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KENWOOD     MODLARI

KENWOOD TM-211 OUT OF BAND MODIFICATIONS

The following is a simple modification for the TM-221 rig:

1- Locate the control unit board (X53-3040-XX) located behind the front panel.

2- Right below the channel select rotary switch and opposite the M.IN Sw.

you will find R24 and R25.(foil side)

3- Remove R25 for 142.00 thru 151.995 Mhz RX TX

4- Move R25 to space for R24 for 138.00 thru 154.000 Mhz TX RX (Range will

vary slightly from set to set)

 

 

EXTENDED RANGE !!

TO GET YOUR 221A TO RECIEVE FROM 138-174 MHZ YOU

NEED TO REMOVE THE FRONT PANEL AND GAIN ACCESS TO THE CHIP RESISTORS

AND REARRANGE THENM AS FOLLOWS:

R22 R23 R24 R25

X O O X X=CONNECTED O=LEFT OUT

IF YOU ARE RUNNING A VK VERSION REMOVAL OF R24 IS ALL THAT IS NEEDED.

THE TX WILL REMAIN AT 144-148MHZ EVEN AFTER THE MOD.

GEOFF VK3KGH @ VK3RPA

A QUICK AND DIRTY FIX FOR THE KNWD TM231A LOW MIC OUTPUT TILL (IF)

KNWD COMES OUT WITH A FIX IS TO BYPASS R 63 (3.3K).

R 63 AND R64 FORM A VOLTAGE DIVIDER AT THE INPUT TO THE MIC AMP.

R63 IS ON THE BOTTOM OF THE RIG. WITH THE BOTTOM COVER OFF AND THE FRONT

OF THE RIG FACING YOU, LOCATE THE MIC AMP BOARD 3610 WHICH STANDS VERTICALLY

OFF THE MOTHER BOARD. FOLLOW THE 3RD PIN FROM THE LEFT TO R63.

A JUMPER HERE GIVES THE TX AUDIO A NICE BOOST.

BE SURE TO READJUST THE DTMF OUTPUT IN THE MIC (THE ONLY POT IN THE MIC).



 

From : DJ9IH

To : KENWOO@EU

Type/status : B$

Date/time : 31-Dec 11:37

BID (MID) : UC8DB0IZ_07L

Message # : 324203

Title : TH-D7E 1.Erfahrungen

Path: !I6BNW!IK6PYS!IK6RUY!I4UKI!IK5CKL!IW5BFZ!IW2FPO!HB9OK!HB9H!HB9OS!HB9EAS!

!DB0CZ!DB0GE!DB0IZ!

From: DJ9IH @ DB0IZ.#NRW.DEU.EU (Gerd)

To: KENWOOD @ EU

X-Info: No login password

Hallo OMs,

ich denke, daá der Erfahrungsaustausch ber Selbstkaufger„te allen

bei der Entscheidungsfindung helfen kann. Meine hier mitgeteilten

Erfahrungen zu Kenwood TH-D7E nach drei Wochen Betrieb sind subjektisch

und nicht meátechnisch untermauert:

Das Ger„t ist ein Computer mit Handsprechfunkger„t fr 2 m und 70 cm mit

(nach Beurteilung von Gegenstationen) guter Modulation. Die

Bedienerfhrung ist nach meinem Eindruck einfacher und logischer als

bei entwicklungstechnisch „lteren Handfunken.

Die Sendeleistung mit externem Anschluá an eine 13,8 V Strom-

versorgung betr„gt max. 5,5 bis 6 Watt. Dabei wird bei l„ngeren

Durchg„ngen der innere Metallrahmen recht heiá. Die Umschalttaste auf

Senden geht zu stramm und fhrt bei l„ngeren Durchg„ngen bei mir

zu Verkrampfungen der Hand.

Die Empfangsleistung l„át nach meiner Beurteilung (ohne exakte Messungen)

im Vergleich zu anderen Duobandern an gleicher Antenne keine Wnsche offen.

Den TNC betreibe ich mit dem Terminalprogramm TERM1040 (liegt u.a.

im EL-Server von DB0GV) ohne Probleme mit 1k2. Bei 9k6 hat das Ger„te

die Nachteile aller PLL-Ger„te, es funktioniert nur bei Digis, deren

TXD etwas langsamer eingestellt ist (z.B. auf 430.775 - DB0IZ ohne

Probleme).

Ein Manko ist bislang folgendes: mit 1k2 und 9k6 geht es

nur auf Digis, die ohne DAMA laufen. Hier muá noch eine L”sung

gefunden werden (Vorschl„ge dazu sind willkommen !).

Ich halte das Ger„t fr den von mir angedachten Zweck, n„mlich fr

fr den Urlaubs- und anderen Portabelbetrieb in Fonie und PR

fr gut geeignet, beim derzeitigen Stand (ohne DAMA) kann

es kein Ersatz fr eine Homestation mit TNC sein.

Ich wrde mich freuen, wenn andere TH-D7E Besitzer sich an dem

Erfahrungsaustausch beteiligen wrden - u.a. DAMA ist noch nicht

gel”st.

vy 73 es alles Gute fr 1999 - Gerd in Solingen DJ9IH@DB0IZ

 

--- End of messsage #324203 to KENWOO from DJ9IH ---

 

From : PE1PYT

To : KENWOO@EU

Type/status : B$

Date/time : 30-Sep 13:28

BID (MID) : 12585_PI8HGL

Message # : 235220

Title : Mods for TH-79A/E

 

Here is a compiled list of modifications and features I've found for the

Kenwood TH79 Dual Band HT.

Thanks to the following for their contributions to this document:

Mike Musick, N0QBF

Cole Cunningham, AA7RD

Duane Voth, KC5BGV

Chuck Scott, N8DNX

Having had many other radios in the past, and certain to have many in

the future, I understand the anticipation of Amateur Radio operators to

find modifications to their equipment. I started this document because I

want to see _quality_ information circulated as quickly as possible, in

order to save a lot of time and effort for others.

If you have any other comments, mods, or information you would like to see

included in this document in the future, please send them to:

Clayton Wagar KD4IDN

[email protected]

Outstanding questions at the time this document was released:

* Rumor of a keypad modification to the radio for "Wide band" TX, RX. If you

know of this mod, please write to me, even if you wish it not to be

published. This would save a number of poor radios from useless torture!

Hope you find all of this information useful. Again, please send corrections

or additions to [email protected]

73 de Clayton

KD4IDN

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Contents of This Document

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer and other foolery

II. Brief Description of the Kenwood TH79A Dual Band Handheld Radio

III. MARS/CAP Modification

IV. Extended TX/RX Modification ('Beyond MARS')

V. Remote Base Operation

VI. Post Modification Specification Chart

VII. Cross Band Repeat

VIII. Other Stuff

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Well, don't you get sick of this stuff? I know, I know. However, I must

say that I cannot and will not be responsible for anything that might

happen to your radio, your person, your dog, or other operators you

might talk to with your th79. In addition, if you decide that, with

your newly modified HT, you just absolutely must cause unlawful

interference with another ham or another radio service, I won't pay your

NAL. Really.

Oh, and while we're at it... The extended RX/TX modifications may

require you to solder or desolder really, really small components. If

you want to know how small, look at the tip of an average ball point pen.

Smaller than that. It takes about 1/2 of a second to wipe out several

components as well as fry the board inside the 79. Please be careful.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

II. TH79 Description and Impressions, by Mike Musick, N0QBF

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Lulled by the sexy small size, I succumbed (or, rather, the

credit card succumbed) and bought a Kenwood TH-79 dual-band H-T

recently. Already owning a TH-78, the comparison comes easy.

SPECS. The TH-79A is a U.S.-spec dual-band transceiver, featuring

coverage from 144-148 and 438-450 MHz. Receive coverage is

extended on the 2M side from 118 to 174 MHz with AM in the

aircraft band; there is no extended UHF coverage without

modification. Max power is rated 5W on VHF and 3.5W on UHF with a

12V source; max power with stock 600 mAH nicad pack is 2.5/2.0.

There are three power levels for each band - high, low, and

extra-low (30mW). There are 80 memory channels, with no evident

expansion capability. U.S./Canada version comes with the CTCSS

encode/decode option. Going price at a 7/17/94 hamfest was $480.

GENERAL IMPRESSIONS. Tiny, tiny, tiny. Imagine putting a small

duckie on the ARRL Repeater Directory - except that the 79 is

narrower by about an inch. With the standard battery and not

counting the belt clip, the dimensions are roughly 2" wide, 5"

tall, and 1" thick. The belt clip adds 3/8" to the thickness; I

left it off so it would be pocketable, and, frankly, it fits

moderately comfortably in my work slacks' front pockets, which

was surprising. It's tiny! (Oh, I said that already.)

The 79's keyboard has larger buttons than it's predecessor (lacks

ENTER = continue, A = Abort, N = Next, C = cancel paging -->

the cover, too) which are much easier to use. Control layout in

general is better and even in just a couple of days I appreciated

the change. No more ambiguous power switch - it's in the primary

band volume knob in a normal OFF/ON/VOL setup. Secondary band

volume control is on the "ring" of the freq/channel encoder knob

in a coaxial arrangement.

There are no squelch knobs; it a key+knob function for both

bands. Squelch control was, well, interesting. There are only six

"settings", with usually only the lowest setting opening the

squelch under no signal. Reading between the lines in the manual,

apparently the squelch circuit is semi-automatic. I expected some

limitations, but had no complaints under actual use - it worked

well.

With my expected habit of putting it in my pocket, I like the

control lock switch - it's *not* an F-key function, but, rather

is a slide switch next to the PTT. No more fumbling around to

unlock it. Unfortunately, the lock function does not lock PTT -

that has to be disabled with the "Tx Stop" menu setting. I found

this out the hard way by putting it in my pocket and

inadvertently keying-up a repeater.

The 79 has an alphanumeric display capability of two lines of 10

characters, which is used in several ways. First, there is a

"guide" facility, which provides online instruction for most

operation features with a scrolling display. Then there is a

"menu" function, which provides access to the settings which were

normally done with obscure F-key commands in the 78. Setting the

various functions is very clear this way. There is also a status

review mode, where the more important settings are displayed.

Finally, the alphanumeric display can be set for each programmed

channel. Seven characters positions are available, and almost the

entire extended ANSI character set - that's right: lower case,

symbols, and accented characters - can be used. However, alpha

display is mutually exclusive with frequency display. Frequency

display mode can be selected in case you forgot what was

"underneath" your programmed channel ID.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

III. MARS/CAP Modification provided by Mike Musick, N0QBF

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is the MARS/CAP modification for the new Kenwood TH-79A

dual-band HT. Usual disclaimers about doing mods apply.

1. Remove battery.

2. Open case by first removing 3 screws (#00 Phillips) on back

and 1 screw on side hidden underneath the rubber flap covering

the DC power jack. Gently pry apart starting at top; BNC

connector will move with back, knobs with front.

3. Spread unit out. Wires will "hinge" on the side with the PTT

button.

4. Looking on the back of the keypad (front) half, locate green

wire on upper left, just below the CTCSS decoder module.

5. Neatly cut this green wire, and tuck back in so ends won't

touch each other or other components.

6. Reassemble.

Programmed memory will be lost since the CPU will notice the

strap change and reset itself.

End result -

Before: VHF RX - 118.000-173.995 TX - 144.000-147.995

UHF RX - 438.000-449.995 TX - 438.000-449.995

After: VHF RX - 118.000-173.995 TX - 142.000-151.995

UHF RX - 420.000-449.995 TX - 420.000-449.995

Automatic repeater offset and shift selections remain normal.

And this tip comes from Duane Voth, KC5BGV...

"The MARS/CAP mod can be made without opening the entire case up. You

can fairly easily cut the green wire by simply (and carefully) removing

the CTCSS decoder cover and using a small pair of diagonal wire cutters."

 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

IV. "Wide Band" Modification, provided by Cole Cunningham, AA7RD

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Following is a modification for the Kenwood TH-79A Dual Band HT which

opens it up to tuning from 67-174 MHz and 400-511 MHz. Actual receive was

85-135.995 AM and 136-179.995 FM with reasonable (0.5 microvolt

or better) sensitivity at all the points I measured. Transmit was

136-179.995 and 400-511 with power dropping off at the ends but still

usable (about 0.5w on the high scale at the band edges).

As usual, I take no responsibility for the mods, or your use of the unit

after mod. Please exercise good judgement and don't endanger our ham bands

with your irresponsible actions.

The observations noted are all I tried and I have no further data.

This is such a delicate operation that one shot was all I wanted to do,

and when it worked I quit!!!

WARNING-CAUTION-LOOKOUT-ETC!!!

The diodes to be moved are microscopic!! About 1mm long by 0.5mm wide.

This mod should be done by professionals on a closed track only.

Children, do not attempt this at home. Requires extremely small soldering

tools and MUCH skill. I had a professional surface mount facility do mine...

 

1. Open the unit by removing three screws from the back and one under the

DC power input cover. Carefully separate the front and back pieces.

The two case halves may be disconnected by pulling the wired plug and by

prying the brown latch on the ribbon cable connector up enough to

release it.

2. On the front PC board in the lower right corner as viewed from the rear

with the knobs pointing up there are seven spots for diodes in a row,

with one diode missing.

|

o o o o x o o |

________________|

2 3 4 5 6 7 8

The numbers are D302-D308, left to right, with D306 missing.

3. Remove D304, and D307. Put them away in a safe place (Just in case...)_

4. You should now have:

|

o o x o x x o |

________________|

2 3 4 5 6 7 8

5. Reassemble and good Luck.

Enjoy, but don't create problems with the new capability...Wouldn't it be

nice if Kenwood would make a RX only mod with these capabilities and we

wouldn't have to worry about accidental transmissions where we shouldn't

be transmitting. I, for one, don't want or need to TX, just RX...

73, Cole, AA7RD

August 11, 1994

(Note - This mod also adds 2 more menu settings. One of which is an

AM/FM demod selector for the 300-400 Mhz band. To access this

band, select the VHF band, press F, then press the Low/Hi key.

Repeat to return to 144 Mhz. The AM/FM selector will allow you

to listen to Military transmissions in the 300Mhz band in

either AM or FM.

- Clayton)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

V. Remote Base Operation with Kenwood 732/733

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Kenwood has now simplified remote base operation of their mobile rigs

with the TH79.

I will not give a step by step on how to control the mobile rigs, since

they are different. Hoewever, to really understand this feature, I would

first get to know the remote control feature on the mobile very well. This

makes the following explanation a little clearer!

To access this feature, hold [PTT] and [MR] while [POWER ON].

The display will indicate -RC-, which I presume means 'Remote Control'.

If you have correctly matched your DTSS codes, frequencies, etc, the

dual bander's keypad now becomes a function pad. Pressing certain keys

enables or disables functions on the mobile rig by sending the DTMF

sequences for you.

Please note that all this fuction does is send the DTMF tones over the air

to control your mobile rig. I have not made a list of what each key does,

but as the 79 sends the DTMF tones, the display will indicate the function.

(i.e. - RPT ON, RPT OFF, TONE ON, TONE OFF, etc.)

73 de Clayton

KD4IDN

And this from Chuck Scott, N8DNX...

"The "RC" function is configured to directly control radios such as

the TM-732. In fact, if you look at the layout of the microphone remote

commands for the 732 it very closely matches the key assignments for of

the "RC" mode. Since I have a TM-732 installed in my car, I had a chance

to try this out and it's VERY convenient. Everything from direct frequency

entry with the "F" key to enabling X-Band repeat. I'm really surprised

ENTER = continue, A = Abort, N = Next, C = cancel paging -->

they aren't marketing this feature of the radio."

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VI. Post Modification Spec Sheet, by Clayton Wagar, KD4IDN

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is a small chart showing the measured specifictions of TH79

S/N 60300272 after modification. The measurements were made with an

IFR 1200S Service Monitor, on the bench, with a 6V power supply.

Your milage may vary - these are just what happened with mine, and

I would suspect that most units are pretty similar.

73 de Clayton

KD4IDN

 

Band - VHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

108 4 - A3

110 2 - "

115 .75 - "

120 .40 - "

125 .30 - "

130 .30 - "

135 .30 - "

140 .12 2.9 F3

145 .12 2.9 "

150 .13 2.8 "

155 .15 2.4 "

160 .18 1.9 "

165 .20 1.45 "

170 .21 1.10 "

175 .30 0.85 "

179.995 .35 0.70 "

 

Band - VHF (2) (set to 300Mhz) --------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

300 50/75 - A3/F3

320 4/20 - "

340 .3/.6 - "

360 .2/.5 - "

380 .2/.6 - "

400 .2/.75 - "

 

Band - UHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

400 11 1.0 F3

410 4 1.5 "

420 1 1.85 "

430 .2 2.2 "

435 .12 2.3 "

440 .10 2.5 "

445 .10 2.5 "

450 .10 2.5 "

455 .15 2.3 "

460 .16 2.3 "

465 .20 2.0 "

470 .45 1.8 "

480 1 1.6 "

490 2 1.3 "

500 6 1.1 "

510 no RX over 509 0.8 "

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VII. Cross Band Repeat, from Chuck Scott, N8DNX

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The TH-79 does go into X-Band repeat. Press the "F" key then the "MONI"

key to enter repeat mode. Use the same to return to normal. There is a

10 min transmit limit so it's not useable for long duration monitoring of

a continuous transmission. That's understandable in light of the number

of horror stories I've heard of people frying their HT's in repeat mode.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VIII. Other Observations, Ramblings, Etc.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

From Chuck Scott, N8DNX....

"Regarding the lack of a memory Lock Out function, I talked at length

with the Kenwood people. They have been inundated calls about this and

have told me that they are preasuring Japan to come up with a processor

replacement to fix this, perhaps as a retrofit. I encourage any owner of

a TH-79 to write to Kenwood insisting on such a modification at no cost

and asking that they be informed when it is available. I think this is

justified for several reasons. First, I have been told by another ham

that the official brochure indicates that such a feature is included.

Second, and more important, it is arguable that the radio is not suited

to the application without memory lockout. After all, it's an 80 channel

radio. To make effective use of that many channels REQUIRES a channel

lockout function. Without effective use of that many channels, the radio

is not comparable to the current standard for such a unit.

BTW, close inspection of the RF deck in my radio shows no obvious

missing parts. I didn't remove the board to check the other side, but

my suspicion is that the 800 MHz parts are installed. I'd be interested

in input from others on that. So far I've not discovered how to make it

display any 800 MHz frequencies though."

=======================================================================

Kenwood TH79 Dual Bander Modification and Feature Guide r1.5 The End!

=======================================================================

 

 

 

--- End of messsage #235220 to KENWOO from PE1PYT ---

******************

Copied fm my local BBS: [email protected]#.TUR.EU;

73' fm TA2CNC, Naci K.

 

----------------------------------------

Here are the mods for the Kenwood Th79-A dual band hand held. I cannot take

credit for any of the mods, however they were given to me so I thought I would

share them. By the way if you have any mods for any other Amateur Equipment

please email them to me and I will be more than willing to share them with

others.

Thanks and 73...Steve VE9SHM

Kenwood TH79 Dual Bander Modification and Feature Guide r1.5 9/13/94

=======================================================================

Clayton Wagar, KD4IDN

920 West Crawford Street #7

Dalton, GA 30720

Here is a compiled list of modifications and features I've found for the

Kenwood TH79 Dual Band HT.

Thanks to the following for their contributions to this document:

Mike Musick, N0QBF

Cole Cunningham, AA7RD

Duane Voth, KC5BGV

Chuck Scott, N8DNX

Having had many other radios in the past, and certain to have many in

the future, I understand the anticipation of Amateur Radio operators to

find modifications to their equipment. I started this document because I

want to see _quality_ information circulated as quickly as possible, in

order to save a lot of time and effort for others.

If you have any other comments, mods, or information you would like to see

included in this document in the future, please send them to:

Clayton Wagar KD4IDN

[email protected]

Outstanding questions at the time this document was released:

* Rumor of a keypad modification to the radio for "Wide band" TX, RX. If you

know of this mod, please write to me, even if you wish it not to be

published. This would save a number of poor radios from useless torture!

Hope you find all of this information useful. Again, please send corrections

or additions to [email protected]

73 de Clayton

KD4IDN

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Contents of This Document

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer and other foolery

II. Brief Description of the Kenwood TH79A Dual Band Handheld Radio

III. MARS/CAP Modification

IV. Extended TX/RX Modification ('Beyond MARS')

V. Remote Base Operation

VI. Post Modification Specification Chart

VII. Cross Band Repeat

VIII. Other Stuff

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Well, don't you get sick of this stuff? I know, I know. However, I must

say that I cannot and will not be responsible for anything that might

happen to your radio, your person, your dog, or other operators you

might talk to with your th79. In addition, if you decide that, with

your newly modified HT, you just absolutely must cause unlawful

interference with another ham or another radio service, I won't pay your

NAL. Really.

Oh, and while we're at it... The extended RX/TX modifications may

require you to solder or desolder really, really small components. If

you want to know how small, look at the tip of an average ball point pen.

Smaller than that. It takes about 1/2 of a second to wipe out several

components as well as fry the board inside the 79. Please be careful.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

II. TH79 Description and Impressions, by Mike Musick, N0QBF

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Lulled by the sexy small size, I succumbed (or, rather, the

credit card succumbed) and bought a Kenwood TH-79 dual-band H-T

recently. Already owning a TH-78, the comparison comes easy.

SPECS. The TH-79A is a U.S.-spec dual-band transceiver, featuring

coverage from 144-148 and 438-450 MHz. Receive coverage is

extended on the 2M side from 118 to 174 MHz with AM in the

aircraft band; there is no extended UHF coverage without

modification. Max power is rated 5W on VHF and 3.5W on UHF with a

12V source; max power with stock 600 mAH nicad pack is 2.5/2.0.

There are three power levels for each band - high, low, and

extra-low (30mW). There are 80 memory channels, with no evident

expansion capability. U.S./Canada version comes with the CTCSS

encode/decode option. Going price at a 7/17/94 hamfest was $480.

GENERAL IMPRESSIONS. Tiny, tiny, tiny. Imagine putting a small

duckie on the ARRL Repeater Directory - except that the 79 is

narrower by about an inch. With the standard battery and not

counting the belt clip, the dimensions are roughly 2" wide, 5"

tall, and 1" thick. The belt clip adds 3/8" to the thickness; I

left it off so it would be pocketable, and, frankly, it fits

moderately comfortably in my work slacks' front pockets, which

was surprising. It's tiny! (Oh, I said that already.)

The 79's keyboard has larger buttons than it's predecessor (lacks

the cover, too) which are much easier to use. Control layout in

general is better and even in just a couple of days I appreciated

the change. No more ambiguous power switch - it's in the primary

band volume knob in a normal OFF/ON/VOL setup. Secondary band

volume control is on the "ring" of the freq/channel encoder knob

in a coaxial arrangement.

There are no squelch knobs; it a key+knob function for both

bands. Squelch control was, well, interesting. There are only six

"settings", with usually only the lowest setting opening the

squelch under no signal. Reading between the lines in the manual,

apparently the squelch circuit is semi-automatic. I expected some

limitations, but had no complaints under actual use - it worked

well.

With my expected habit of putting it in my pocket, I like the

control lock switch - it's *not* an F-key function, but, rather

is a slide switch next to the PTT. No more fumbling around to

unlock it. Unfortunately, the lock function does not lock PTT -

that has to be disabled with the "Tx Stop" menu setting. I found

this out the hard way by putting it in my pocket and

inadvertently keying-up a repeater.

The 79 has an alphanumeric display capability of two lines of 10

characters, which is used in several ways. First, there is a

"guide" facility, which provides online instruction for most

operation features with a scrolling display. Then there is a

"menu" function, which provides access to the settings which were

normally done with obscure F-key commands in the 78. Setting the

various functions is very clear this way. There is also a status

review mode, where the more important settings are displayed.

Finally, the alphanumeric display can be set for each programmed

channel. Seven characters positions are available, and almost the

entire extended ANSI character set - that's right: lower case,

symbols, and accented characters - can be used. However, alpha

display is mutually exclusive with frequency display. Frequency

display mode can be selected in case you forgot what was

"underneath" your programmed channel ID.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

III. MARS/CAP Modification provided by Mike Musick, N0QBF

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is the MARS/CAP modification for the new Kenwood TH-79A

dual-band HT. Usual disclaimers about doing mods apply.

1. Remove battery.

2. Open case by first removing 3 screws (#00 Phillips) on back

and 1 screw on side hidden underneath the rubber flap covering

the DC power jack. Gently pry apart starting at top; BNC

connector will move with back, knobs with front.

3. Spread unit out. Wires will "hinge" on the side with the PTT

button.

4. Looking on the back of the keypad (front) half, locate green

wire on upper left, just below the CTCSS decoder module.

5. Neatly cut this green wire, and tuck back in so ends won't

touch each other or other components.

6. Reassemble.

Programmed memory will be lost since the CPU will notice the

strap change and reset itself.



End result -

Before: VHF RX - 118.000-173.995 TX - 144.000-147.995

UHF RX - 438.000-449.995 TX - 438.000-449.995

After: VHF RX - 118.000-173.995 TX - 142.000-151.995

UHF RX - 420.000-449.995 TX - 420.000-449.995

Automatic repeater offset and shift selections remain normal.

And this tip comes from Duane Voth, KC5BGV...

"The MARS/CAP mod can be made without opening the entire case up. You

can fairly easily cut the green wire by simply (and carefully) removing

the CTCSS decoder cover and using a small pair of diagonal wire cutters."

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

IV. "Wide Band" Modification, provided by Cole Cunningham, AA7RD

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Following is a modification for the Kenwood TH-79A Dual Band HT which

opens it up to tuning from 67-174 MHz and 400-511 MHz. Actual receive was

85-135.995 AM and 136-179.995 FM with reasonable (0.5 microvolt

or better) sensitivity at all the points I measured. Transmit was

136-179.995 and 400-511 with power dropping off at the ends but still

usable (about 0.5w on the high scale at the band edges).

As usual, I take no responsibility for the mods, or your use of the unit

after mod. Please exercise good judgement and don't endanger our ham bands

with your irresponsible actions.

The observations noted are all I tried and I have no further data.

This is such a delicate operation that one shot was all I wanted to do,

and when it worked I quit!!!

WARNING-CAUTION-LOOKOUT-ETC!!!

The diodes to be moved are microscopic!! About 1mm long by 0.5mm wide.

This mod should be done by professionals on a closed track only.

Children, do not attempt this at home. Requires extremely small soldering

tools and MUCH skill. I had a professional surface mount facility do mine...

 

1. Open the unit by removing three screws from the back and one under the

DC power input cover. Carefully separate the front and back pieces.

The two case halves may be disconnected by pulling the wired plug and by

prying the brown latch on the ribbon cable connector up enough to

release it.

2. On the front PC board in the lower right corner as viewed from the rear

with the knobs pointing up there are seven spots for diodes in a row,

with one diode missing.

|

o o o o x o o |

________________|

2 3 4 5 6 7 8

The numbers are D302-D308, left to right, with D306 missing.

3. Remove D304, and D307. Put them away in a safe place (Just in case...)_

4. You should now have:

|

o o x o x x o |

________________|

2 3 4 5 6 7 8

5. Reassemble and good Luck.

Enjoy, but don't create problems with the new capability...Wouldn't it be

nice if Kenwood would make a RX only mod with these capabilities and we



wouldn't have to worry about accidental transmissions where we shouldn't

be transmitting. I, for one, don't want or need to TX, just RX...

73, Cole, AA7RD

August 11, 1994

(Note - This mod also adds 2 more menu settings. One of which is an

AM/FM demod selector for the 300-400 Mhz band. To access this

band, select the VHF band, press F, then press the Low/Hi key.

Repeat to return to 144 Mhz. The AM/FM selector will allow you

to listen to Military transmissions in the 300Mhz band in

either AM or FM.

- Clayton)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

V. Remote Base Operation with Kenwood 732/733

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Kenwood has now simplified remote base operation of their mobile rigs

with the TH79.

I will not give a step by step on how to control the mobile rigs, since

they are different. Hoewever, to really understand this feature, I would

first get to know the remote control feature on the mobile very well. This

makes the following explanation a little clearer!

To access this feature, hold [PTT] and [MR] while [POWER ON].

The display will indicate -RC-, which I presume means 'Remote Control'.

If you have correctly matched your DTSS codes, frequencies, etc, the

dual bander's keypad now becomes a function pad. Pressing certain keys

enables or disables functions on the mobile rig by sending the DTMF

sequences for you.

Please note that all this fuction does is send the DTMF tones over the air

to control your mobile rig. I have not made a list of what each key does,

but as the 79 sends the DTMF tones, the display will indicate the function.

(i.e. - RPT ON, RPT OFF, TONE ON, TONE OFF, etc.)

73 de Clayton

KD4IDN

And this from Chuck Scott, N8DNX...

"The "RC" function is configured to directly control radios such as

the TM-732. In fact, if you look at the layout of the microphone remote

commands for the 732 it very closely matches the key assignments for of

the "RC" mode. Since I have a TM-732 installed in my car, I had a chance

to try this out and it's VERY convenient. Everything from direct frequency

entry with the "F" key to enabling X-Band repeat. I'm really surprised

they aren't marketing this feature of the radio."

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VI. Post Modification Spec Sheet, by Clayton Wagar, KD4IDN

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is a small chart showing the measured specifictions of TH79

S/N 60300272 after modification. The measurements were made with an

IFR 1200S Service Monitor, on the bench, with a 6V power supply.

Your milage may vary - these are just what happened with mine, and

I would suspect that most units are pretty similar.

73 de Clayton

KD4IDN

 

Band - VHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

108 4 - A3

110 2 - "

115 .75 - "

120 .40 - "

125 .30 - "

130 .30 - "

135 .30 - "

140 .12 2.9 F3

145 .12 2.9 "

150 .13 2.8 "

155 .15 2.4 "

160 .18 1.9 "

165 .20 1.45 "

170 .21 1.10 "

175 .30 0.85 "

179.995 .35 0.70 "

 

Band - VHF (2) (set to 300Mhz) --------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

300 50/75 - A3/F3

320 4/20 - "

340 .3/.6 - "

360 .2/.5 - "

380 .2/.6 - "

400 .2/.75 - "

 

Band - UHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

400 11 1.0 F3

410 4 1.5 "

420 1 1.85 "

430 .2 2.2 "

435 .12 2.3 "

440 .10 2.5 "

445 .10 2.5 "

450 .10 2.5 "

455 .15 2.3 "

460 .16 2.3 "

465 .20 2.0 "

470 .45 1.8 "

480 1 1.6 "

490 2 1.3 "

500 6 1.1 "

510 no RX over 509 0.8 "

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VII. Cross Band Repeat, from Chuck Scott, N8DNX

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The TH-79 does go into X-Band repeat. Press the "F" key then the "MONI"

key to enter repeat mode. Use the same to return to normal. There is a

10 min transmit limit so it's not useable for long duration monitoring of

a continuous transmission. That's understandable in light of the number

of horror stories I've heard of people frying their HT's in repeat mode.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

VIII. Other Observations, Ramblings, Etc.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

>From Chuck Scott, N8DNX....

"Regarding the lack of a memory Lock Out function, I talked at length

with the Kenwood people. They have been inundated calls about this and

have told me that they are preasuring Japan to come up with a processor

replacement to fix this, perhaps as a retrofit. I encourage any owner of

a TH-79 to write to Kenwood insisting on such a modification at no cost

and asking that they be informed when it is available. I think this is

justified for several reasons. First, I have been told by another ham

that the official brochure indicates that such a feature is included.

Second, and more important, it is arguable that the radio is not suited

to the application without memory lockout. After all, it's an 80 channel

radio. To make effective use of that many channels REQUIRES a channel

lockout function. Without effective use of that many channels, the radio

is not comparable to the current standard for such a unit.

BTW, close inspection of the RF deck in my radio shows no obvious

missing parts. I didn't remove the board to check the other side, but

my suspicion is that the 800 MHz parts are installed. I'd be interested

in input from others on that. So far I've not discovered how to make it

display any 800 MHz frequencies though."

=======================================================================

Kenwood TH79 Dual Bander Modification and Feature Guide r1.5 The End!

=======================================================================

 

 

 

 

 

ÜÜÜ

CIAO da IK4ZIH Fabio ! ººº³ººº JN64GB Rimini Italy

º ë ë º

___________________________oOOo___­\_é_/­___oOOo_______________________________

 

TH79

Original from N0NEJ to W0XK

#: 288217 S8/Equipment/Antennas

23-Jul-94 23:43:01

Sb: #Kwd TH-79A MARS/CAP Mod

Fm: Mike Musick/N0QBF 71301,3106

 

Here is the MARS/CAP modification for the new Kenwood TH-79A dual-band HT.

Usual disclaimers about doing mods apply.

 

1. Remove battery.

 

2. Open case by first removing 3 screws (#00 Phillips) on back and 1 screw on

side hidden underneath the rubber flap covering the DC power jack. Gently pry

apart starting at top; BNC connector will move with back, knobs with front.

 

3. Spread unit out. Wires will "hinge" on the side with the PTT button.

 

4. Looking on the back of the keypad (front) half, locate green wire on upper

left, just below the CTCSS decoder module.

 

5. Neatly cut this green wire, and tuck back in so ends won't touch each other

or other components.

 

6. Reassemble.

 

Programmed memory will be lost since the CPU will notice the strap change and

reset itself.

 

End result -

 

Before: VHF RX - 118.000-173.995 TX - 144.000-147.995

UHF RX - 438.000-449.995 TX - 438.000-449.995

 

After: VHF RX - 118.000-173.995 TX - 142.000-151.995

UHF RX - 420.000-449.995 TX - 420.000-449.995

 

Automatic repeater offset and shift selections remain normal.

 

If I read the schematic right, the green wire corresponds to "W301", which

also serves the same purpose as removing "D308". More research needs to be

done on other mods; I'm especially interested in extending UHF receive beyond

450.

 

There is a row of diodes right below the uC which appear to be D302 through

D308, the configuration straps. HOWEVER - I need to caution anybody thinking

about playing with the diode straps that it will not be a casual operation.

For one thing, the diodes are SMD "603" style - extra, extra tiny - and the

plastic board hold-downs molded into the front case are right on the landings

for most of the diodes. This means that the board will have to be removed from

the case (a very involved procedure), and working with the tiny diodes *will*

require magnification tools as well as the correct micro-tip iron. It is not a

job for the inexperienced or all-thumbs.

 

Also, as noted previously, the non-US versions of the TH-79 have an 800 MHz

receive section. All RF components of this section are not present in the US

version. Frankly, it would easier to import a gray-market version of the radio

than it would be to attempt restoring this coverage in the US with parts.

 



 

From : CT1FMS

To : MODS@WW

Type/status : B$

Date/time : 07-Jan 17:24

BID (MID) : 60745_CT1FMS

Message # : 325586

Title : MODS -->KENWOOD TH79

Path: !VK7AX!VE1SMU!N5VDA!LX0IST!PP5BLU!KA3FMO!N4ZKF!KP4IG!CX4FY!EB1DIG!

!EA7VA!EA7MU!ZB2BL!CT1XK!CT1FOT!CT1FMS!

 

 

 

From: [email protected]

To : MODS@WW

Kenwood TH79 Dual Bander Modification and Feature Guide r1.5 9/13/94

=======================================================================

Here is a compiled list of modifications and features I've found for the

Kenwood TH79 Dual Band HT.

 

Having had many other radios in the past, and certain to have many in

the future, I understand the anticipation of Amateur Radio operators to

find modifications to their equipment. I started this document because I

want to see _quality_ information circulated as quickly as possible, in

order to save a lot of time and effort for others.

 

Outstanding questions at the time this document was released:

* Rumor of a keypad modification to the radio for "Wide band" TX, RX. If you

know of this mod, please write to me, even if you wish it not to be

published. This would save a number of poor radios from useless torture!

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Contents of This Document

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer and other foolery

II. Brief Description of the Kenwood TH79A Dual Band Handheld Radio

III. MARS/CAP Modification

IV. Extended TX/RX Modification ('Beyond MARS')

V. Remote Base Operation

VI. Post Modification Specification Chart

VII. Cross Band Repeat

VIII. Other Stuff

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I. Disclaimer

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Well, don't you get sick of this stuff? I know, I know. However, I must

say that I cannot and will not be responsible for anything that might

happen to your radio, your person, your dog, or other operators you

might talk to with your th79. In addition, if you decide that, with

your newly modified HT, you just absolutely must cause unlawful

interference with another ham or another radio service, I won't pay your

NAL. Really.

Oh, and while we're at it... The extended RX/TX modifications may

require you to solder or desolder really, really small components. If

you want to know how small, look at the tip of an average ball point pen.

Smaller than that. It takes about 1/2 of a second to wipe out several

components as well as fry the board inside the 79. Please be careful.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Lulled by the sexy small size, I succumbed (or, rather, the

credit card succumbed) and bought a Kenwood TH-79 dual-band H-T

recently. Already owning a TH-78, the comparison comes easy.

SPECS. The TH-79A is a U.S.-spec dual-band transceiver, featuring

coverage from 144-148 and 438-450 MHz. Receive coverage is

extended on the 2M side from 118 to 174 MHz with AM in the

aircraft band; there is no extended UHF coverage without

modification. Max power is rated 5W on VHF and 3.5W on UHF with a

12V source; max power with stock 600 mAH nicad pack is 2.5/2.0.

There are three power levels for each band - high, low, and

extra-low (30mW). There are 80 memory channels, with no evident

expansion capability. U.S./Canada version comes with the CTCSS

encode/decode option. Going price at a 7/17/94 hamfest was $480.

GENERAL IMPRESSIONS. Tiny, tiny, tiny. Imagine putting a small

duckie on the ARRL Repeater Directory - except that the 79 is

narrower by about an inch. With the standard battery and not

counting the belt clip, the dimensions are roughly 2" wide, 5"

tall, and 1" thick. The belt clip adds 3/8" to the thickness; I

left it off so it would be pocketable, and, frankly, it fits

moderately comfortably in my work slacks' front pockets, which

was surprising. It's tiny! (Oh, I said that already.)

The 79's keyboard has larger buttons than it's predecessor (lacks

the cover, too) which are much easier to use. Control layout in

general is better and even in just a couple of days I appreciated

the change. No more ambiguous power switch - it's in the primary

band volume knob in a normal OFF/ON/VOL setup. Secondary band

volume control is on the "ring" of the freq/channel encoder knob

in a coaxial arrangement.

There are no squelch knobs; it a key+knob function for both

bands. Squelch control was, well, interesting. There are only six

"settings", with usually only the lowest setting opening the

squelch under no signal. Reading between the lines in the manual,

apparently the squelch circuit is semi-automatic. I expected some

limitations, but had no complaints under actual use - it worked

well.

With my expected habit of putting it in my pocket, I like the

control lock switch - it's *not* an F-key function, but, rather

is a slide switch next to the PTT. No more fumbling around to

unlock it. Unfortunately, the lock function does not lock PTT -

that has to be disabled with the "Tx Stop" menu setting. I found

this out the hard way by putting it in my pocket and

inadvertently keying-up a repeater.

The 79 has an alphanumeric display capability of two lines of 10

characters, which is used in several ways. First, there is a

"guide" facility, which provides online instruction for most

operation features with a scrolling display. Then there is a

"menu" function, which provides access to the settings which were

normally done with obscure F-key commands in the 78. Setting the

various functions is very clear this way. There is also a status

review mode, where the more important settings are displayed.

Finally, the alphanumeric display can be set for each programmed

channel. Seven characters positions are available, and almost the

entire extended ANSI character set - that's right: lower case,

symbols, and accented characters - can be used. However, alpha

display is mutually exclusive with frequency display. Frequency

display mode can be selected in case you forgot what was

"underneath" your programmed channel ID.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is the MARS/CAP modification for the new Kenwood TH-79A

dual-band HT. Usual disclaimers about doing mods apply.

1. Remove battery.

2. Open case by first removing 3 screws (#00 Phillips) on back

and 1 screw on side hidden underneath the rubber flap covering

the DC power jack. Gently pry apart starting at top; BNC

connector will move with back, knobs with front.

3. Spread unit out. Wires will "hinge" on the side with the PTT

button.

4. Looking on the back of the keypad (front) half, locate green

wire on upper left, just below the CTCSS decoder module.

5. Neatly cut this green wire, and tuck back in so ends won't

touch each other or other components.

6. Reassemble.

Programmed memory will be lost since the CPU will notice the

strap change and reset itself.

End result -

Before: VHF RX - 118.000-173.995 TX - 144.000-147.995

UHF RX - 438.000-449.995 TX - 438.000-449.995

After: VHF RX - 118.000-173.995 TX - 142.000-151.995

UHF RX - 420.000-449.995 TX - 420.000-449.995

Automatic repeater offset and shift selections remain normal.

 

"The MARS/CAP mod can be made without opening the entire case up. You

can fairly easily cut the green wire by simply (and carefully) removing

the CTCSS decoder cover and using a small pair of diagonal wire cutters."

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Following is a modification for the Kenwood TH-79A Dual Band HT which

opens it up to tuning from 67-174 MHz and 400-511 MHz. Actual receive was

85-135.995 AM and 136-179.995 FM with reasonable (0.5 microvolt

or better) sensitivity at all the points I measured. Transmit was

136-179.995 and 400-511 with power dropping off at the ends but still

usable (about 0.5w on the high scale at the band edges).

As usual, I take no responsibility for the mods, or your use of the unit

after mod. Please exercise good judgement and don't endanger our ham bands

with your irresponsible actions.

The observations noted are all I tried and I have no further data.

This is such a delicate operation that one shot was all I wanted to do,

and when it worked I quit!!!

WARNING-CAUTION-LOOKOUT-ETC!!!

The diodes to be moved are microscopic!! About 1mm long by 0.5mm wide.

This mod should be done by professionals on a closed track only.

Children, do not attempt this at home. Requires extremely small soldering

tools and MUCH skill. I had a professional surface mount facility do mine...

 

1. Open the unit by removing three screws from the back and one under the

DC power input cover. Carefully separate the front and back pieces.

The two case halves may be disconnected by pulling the wired plug and by

prying the brown latch on the ribbon cable connector up enough to

release it.

2. On the front PC board in the lower right corner as viewed from the rear

with the knobs pointing up there are seven spots for diodes in a row,

with one diode missing.

|

o o o o x o o |

________________|

2 3 4 5 6 7 8

The numbers are D302-D308, left to right, with D306 missing.

3. Remove D304, and D307. Put them away in a safe place (Just in case...)_

4. You should now have:

|

o o x o x x o |

________________|

2 3 4 5 6 7 8

5. Reassemble and good Luck.

Enjoy, but don't create problems with the new capability...Wouldn't it be

nice if Kenwood would make a RX only mod with these capabilities and we

wouldn't have to worry about accidental transmissions where we shouldn't

be transmitting. I, for one, don't want or need to TX, just RX...

 

(Note - This mod also adds 2 more menu settings. One of which is an

AM/FM demod selector for the 300-400 Mhz band. To access this

band, select the VHF band, press F, then press the Low/Hi key.

Repeat to return to 144 Mhz. The AM/FM selector will allow you

to listen to Military transmissions in the 300Mhz band in

either AM or FM.

- Clayton)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

V. Remote Base Operation with Kenwood 732/733

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Kenwood has now simplified remote base operation of their mobile rigs

with the TH79.

I will not give a step by step on how to control the mobile rigs, since

they are different. Hoewever, to really understand this feature, I would

first get to know the remote control feature on the mobile very well. This

makes the following explanation a little clearer!

To access this feature, hold [PTT] and [MR] while [POWER ON].

The display will indicate -RC-, which I presume means 'Remote Control'.

If you have correctly matched your DTSS codes, frequencies, etc, the

dual bander's keypad now becomes a function pad. Pressing certain keys

enables or disables functions on the mobile rig by sending the DTMF

sequences for you.

Please note that all this fuction does is send the DTMF tones over the air

to control your mobile rig. I have not made a list of what each key does,

but as the 79 sends the DTMF tones, the display will indicate the function.

(i.e. - RPT ON, RPT OFF, TONE ON, TONE OFF, etc.)

 

"The "RC" function is configured to directly control radios such as

the TM-732. In fact, if you look at the layout of the microphone remote

commands for the 732 it very closely matches the key assignments for of

the "RC" mode. Since I have a TM-732 installed in my car, I had a chance

to try this out and it's VERY convenient. Everything from direct frequency

entry with the "F" key to enabling X-Band repeat. I'm really surprised

they aren't marketing this feature of the radio."

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is a small chart showing the measured specifictions of TH79

S/N 60300272 after modification. The measurements were made with an

IFR 1200S Service Monitor, on the bench, with a 6V power supply.

Your milage may vary - these are just what happened with mine, and

I would suspect that most units are pretty similar.

 

 

Band - VHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

108 4 - A3

110 2 - "

115 .75 - "

120 .40 - "

125 .30 - "

130 .30 - "

135 .30 - "

140 .12 2.9 F3

145 .12 2.9 "

150 .13 2.8 "

155 .15 2.4 "

160 .18 1.9 "

165 .20 1.45 "

170 .21 1.10 "

175 .30 0.85 "

179.995 .35 0.70 "

 

Band - VHF (2) (set to 300Mhz) --------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

300 50/75 - A3/F3

320 4/20 - "

340 .3/.6 - "

360 .2/.5 - "

380 .2/.6 - "

400 .2/.75 - "

 

Band - UHF -----------------------------------------------------

Frequency Sens (uV) Power Mode

--------- --------- ----- ----

400 11 1.0 F3

410 4 1.5 "

420 1 1.85 "

430 .2 2.2 "

435 .12 2.3 "

440 .10 2.5 "

445 .10 2.5 "

450 .10 2.5 "

455 .15 2.3 "

460 .16 2.3 "

465 .20 2.0 "

470 .45 1.8 "

480 1 1.6 "

490 2 1.3 "

500 6 1.1 "

510 no RX over 509 0.8 "

 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The TH-79 does go into X-Band repeat. Press the "F" key then the "MONI"

key to enter repeat mode. Use the same to return to normal. There is a

10 min transmit limit so it's not useable for long duration monitoring of

a continuous transmission. That's understandable in light of the number

of horror stories I've heard of people frying their HT's in repeat mode.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 

"Regarding the lack of a memory Lock Out function, I talked at length

with the Kenwood people. They have been inundated calls about this and

have told me that they are preasuring Japan to come up with a processor

replacement to fix this, perhaps as a retrofit. I encourage any owner of

a TH-79 to write to Kenwood insisting on such a modification at no cost

and asking that they be informed when it is available. I think this is

justified for several reasons. First, I have been told by another ham

that the official brochure indicates that such a feature is included.

Second, and more important, it is arguable that the radio is not suited

to the application without memory lockout. After all, it's an 80 channel

radio. To make effective use of that many channels REQUIRES a channel

lockout function. Without effective use of that many channels, the radio

is not comparable to the current standard for such a unit.

BTW, close inspection of the RF deck in my radio shows no obvious

missing parts. I didn't remove the board to check the other side, but

my suspicion is that the 800 MHz parts are installed. I'd be interested

in input from others on that. So far I've not discovered how to make it

display any 800 MHz frequencies though."

=======================================================================

Kenwood TH79 Dual Bander Modification and Feature Guide r1.5 The End!

=======================================================================

 

I would like to inform you about the modification on my TH-79A handheld

according to the information you sent me.

I had an outfit complete the modification - they charged me one hours labour.

Here is what the end result was after they removed dioides D304 and D307

VHF Coverage: Receive and transmit = 136.00 to 173.00 Mhz

UHF Coverage: Receive and transmit = 410.00 to 469.00 Mhz

I was surprised to find out that I lost the extended AM receive coverage,

that is the 118.00 - 135.99 Mhz coverage.

My frequency transmit range is quite different than that described in the

information you sent me. Anyhow, I am pleased that I have extended UHF

receive coverage.

I would like to share a trick. For those that are paranoid in

accidentally trasmitting outside the Ham bands, this can be overcome by

setting the frequencies in the Programmable VHF and UHF frequencies using

the Menu function.

Furthermore, if you would have any information on a memory lockout

function on the TH-79A I would be very much appreciated.

Thankfully Yours,

 

 

 

Best 73. Paulo, [email protected]

 

 

 

 

 

 

 

--- End of messsage #325586 to MODS from CT1FMS ---

 

TH-78A (U.S.A. version) --> TH78E (European version) MODS.

**********************************************************

Hello TH78 user,

If you bought a TH78A in the USA you don't have the 1750 Hz repeater tone

access, but you can change that !

Apart from the well-known six diodes, the new CPU has 2 green wires.

In order to use the TH78A in EU, you must do the following:

- First you have to remove D2 for the standard EU bands (144-146 and

430-440 MHz).

- Now control that the 2 green wires and the 5 other diodes are installed

(D1, D3, D4, D5 and D6).

- If you need band expantion and components location, please see the mods

below.

Although the TH78A has a special bandpass filter for the US 70cm band, I could

not notice a decrease in sensitivity in the EU part of the 70 cm band.

There is a function change for 3 knobs; please see below and also p. 6 and 7 of

your INSTRUCTION MANUAL.

TH-78A --> TH-78E

---------------------------

LAMP --> TONE 1750 Hz

CALL --> LAMP

TONE --> CALL

Now, you can choice between the CTCSS tones and the 1750 Hz with the following

sequence: F + LAMP (the new TONE !) and then the right rotary encoder to make

your frequency choice.

 

*******************************************************************************

KENWOOD TH-78E MODS

*******************

 

Hello TH-78E user,

I recently bought a TH-78E which apparently had a new CPU. You can see this

internally. Apart from the well-known six diodes it also has two green wires,

indicated on the PCB as W1 and W2.

WARNING !!!

-----------

In the course of performing mods on my Kenwood TH-78E dual band handheld,

I've discovered a potential flaw in the case design. While handling my walkie

one day (after the mods were done), the display went blank and I could not

turn the radio back on. With the radio split in half again, I could turn the

radio back on but discovered all the memories were erased. The cause turned

out to be some component pins on the front face coming in contact with the

square bodies of the two volume/channel/squelch switches, when the case is

screwed back together snuggly. I placed small strips of electrical tape on

the sides of the switches to insulate, and reassembled; problem solved. Now,

I had to reprogram the darn thing....

===============================================================================

The Guide to Undocumented Features of the TH-78E

------------------------------------------------

The information contained in this document is derived from many sources. Thanks

to all. This document is probably not complete; if you have more info's, please

send it to me.

1. Hardware Mods

----------------

Hardware modifications for the TH-78E are performed by manipulating 2 green

wires and a series of 6 surface mounted diodes, identified as D1 through D6.

The TH-78E block diagram contains a table identifying configurations involving

D2, D3, D5, and D6. However, none of the configurations described below are

included in that table.

To open the radio, follow the instructions on p. 64 of the INSTRUCTION MANUAL.

The two TX/RX busy indicators (LEDs) have rubber seals placed over them. These

have a tendency to fall off when opening or closing the radio.

The diodes and wires are located on the CPU board, which is mounted inside the

front panel of the radio. The CPU board is readily identified by a brass shield

covering the CPU, as well as the socket for the ME-1 memory expansion chip.

All position references in this document assume that you are looking at the

CPU board with the rotary encoders and TX/RX busy indicators at the top.

If you have installed the ME-1 EEPROM, I recommend that you temporarily

remove it to facilitate access to the diodes.

The diodes are located in a vertical row just below the lower right corner

of the brass shield. The diodes are numbered sequentially, starting with

D1 at the top.

The E3 configuration (144-146 and 430-440 MHz) has diodes D1, D3, D4, D5 and D6

and the 2 green wires in place.

Remove jumper W1 (one of the two green wires).

RX is: 50-136 AM, 136-180 FM, 300-400 AM/FM, 400-512 FM (VHF SIDE).

50-180 FM, 400-512 FM, 800-1000 FM (UHF SIDE).

TX is: 136-180 FM and 400-512 FM.

Now, you can reprogram the vfo's limits like explained on p.15 of the

INSTRUCTION MANUAL.

Crossband repeat mod: Remove D4.

 

2. Software Mod

---------------

If you don't need the TX MOD, try the following:

Push PTT + VFO and POWER ON.

TX is not affected, RX is like above.

 

3. Undocumented Features

------------------------

Crossband Repeater: Press F for 1 second, then 0 (requires D4 mod). Repeat the

same sequence to disable.

Cloning: Press 0 during power-up. Allows cloning over the air. All keys except

PTT and POWER are disabled. Press PTT to send DTMF cloning sequence.

Presumably, receiving TH-78E must be in same mode.

Toggle SHIFT/SPLIT Mode: Press SHIFT during power-up. This is described in

the manual, but the documentation is not complete. The TH-78E can

operate in two modes: In SPLIT mode, non-standard offsets (i.e. split

frequencies) are supported, but the default offset is not programmable.

In SHIFT mode, non-standard offsets are not allowed, but the default

offset is programmable. To select the default offset, press F for 1

second, then SHIFT. See p. 30 of the manual for details on changing the

default offset.

Toggle CALL Button Function: Press CALL during power-up. The CALL button

can operate in one of two modes. In the default mode (CALLSW), it

switches between the call channel and the last memory channel (if in

memory recall mode) or last frequency (if in VFO mode). After toggling

the CALL button functionality (VMC), it will switch from the VFO to the

last memory channel and then back to the CALL channel.

AM/FM switching: Hold down VFO key and switch the POWER ON to switch between AM

and FM reception. This work only in the 300 MHz band !

VHF & UHF expansion: Press the F key for 1 second, then press the BAND key. On

VHF you have now 300-400 AM/FM RX and on UHF 800-1000 FM RX.

Channel display mode: Hold down 3 key and switch the POWER ON. Channels are

displayed by number instead of frequency. (NOTE: this function only works

when Alpha-Numeric memory is enabled).

 

4. Considerations

-----------------

The display range of the TH-78 is very wide, but usefull range is more little

and is different from one set to the other. For some frequencies, the TH-78

will "beep": this is PLL unlock and there is no RX/TX ! For high frequencies

the red TX led will not glow: no TX ! The locking ranges are different on

MAIN BAND and SUB BAND.

When monitoring 2 VHF freq., the sensitivity of the MAIN VHF BAND is attenuated

but VHF SUB BAND is still good. Thus monitor strong VHF signals on VHF MAIN

BAND and weak VHF signals on VHF SUB BAND. VHF SUB BAND work only in FM and

not in AM.

When monitoring (VHF or UHF) out of ham band signals, sensitivity is realy

better in SUB BAND. Also the rubber duck antenna has only a good efficiency

in the ham frequencies, that's why my preference go to the 37 cm long COMET

CH-600MX antenna.

Sensitivity in the 959 MHz portable telephone band is low, but good enough to

listen the neighbours cordless telephones.

Sensitivity in the 300 MHz band is very low.

When charging PB13 battery, you need 15.5 V on the DC IN TERMINAL to have a

charge current of 70 mA (1/10 of C) for 15 H.

 

*******************************************************************************

 

*** GAME *** (Available without any modifications)

--------------------------------------------------

Hold down the M and PTT keys and switch the power ON.

(Be very careful the PTT is depressed or else a memory reset will occur.)

1) Play the memory game.

The radio will beep and display one of the following characters: "1, 2, 3, F"

(top row of buttons). Radio starts with one character and adds a new one on

after every round until 20 characters are reached. You must press the keys in

the same sequence they are displayed. When you can follow the radio for 20

characters, then you will win 100 coins and enter the poker game.

(Note: I am terrible at this game, so I cheated by writing down the character

sequence on paper.)

2) Poker game. (Much more interesting than the first game, IMHO)

Place the bet (1 to 10).

Increase the bet with the up key 2, decrease the bet with the down key 5.

Press F to deal the cards.

Cards are (2,3,4,5,6,7,8,9,+,J,K,Q,A NOTE: 10 = "+")

Press PTT to see the suits.

Press numbers 1 through 5 to change the respective cards.

Press F to deal the new cards.

If you win any amount, you can bet for double or nothing.

Press F to play "BIG or SMALL".

Press LOW to keep your winnings.

BIG or SMALL

------------

Arandom card will be chosen.

Push 2 (big) if you think this card is going to be larger than 8.

Push 5 (small) if you think this card is going to be less and 8.

(if an 8 is drawn, then a tie occurs, and you neither win nor lose)

Press F to draw the random card.

You either double your winnings or lost it all.

Press F to continue playing Big or Small.

Press LOW to keep winnings and continue playing poker.

Push the LAMP key to exit the game mode.

Note: While in game mode, receive functions still operate!

 

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Game Mode: Press M and PTT during power-up (be careful not to accidentally

reset the memory (M+POWER)).

To exit the game mode at any time, press the LAMP key. It is not possible

to change the volume, lamp, or frequency settings while in game mode. The

top part of the display will show H.00, which represents the high score.

The lower part shows a scrolling message, "PRESS ANY KEY". Pushing any key

starts a "Follow Simon" type game. The display will briefly show one of

the characters "1", "2", "3", or "F". Press the corresponding key. The game

consists of repeating the displayed character sequence, which increases by one

character each round.

After you "win" the Simon memory game by getting correctly entering a

sequence of twenty characters, the next game is a draw poker game. The way

it works is that you choose your bet (from 1 to 10) by pressing 2 to

increment the bet and 5 to decrement the bet. Then, press F to deal the

five cards. The face value of the cards is displayed, and the suits can be

seen at any time by holding down the PTT key. Any number of cards may be

discarded, and to select (or deselect) a card for discarding, press the keys

1, 2, 3, 4, or 5. If a card is selected for discard, it is displayed

"face-down".

Press F again to draw new cards. Your new cards will be displayed, and

then if your hand is 2-pair or better, the screen will show the rank of

your hand on the left (2P for 2-pair, 4K for four-of-a-kind, etc.). On the

right the pay- off for that hand will be displayed. Your bet is multiplied

by the pay-off factor,and the resulting pile of cash is displayed in the

right hand side of the upper screen. (The left hand side of the upper screen

contains your table stakes, which are initially 100 coins from winning the

Simon game.)

If you win the poker hand, pressing any key steps into the next stage. If

you lose the poker hand, your bet is deducted from your stakes and you are

asked to start another poker hand. In the next stage, you are asked "TRYB/S"

which means, "Do you want to try double-or-nothing in a guessing game for Big

or Small cards?" Press F for yes, press TONE for no. If you say no, your

winnings are credited into your stakes and you are asked to start another poker

hand. If you say yes, then a single shuffling/incrementing card is displayed

on the left, and three stars are displayed on the right. You have to choose to

go for either BIG or SMALL, by pressing 2 or 5. You can keep pressing 2 and 5

to change your mind. When you are ready, you must try to hit the F key to stop

the rotating card display, and the card will show, and you will either win,

lose, or draw. If you draw, you have to play big/small again, I think. If you

lose, your winnings are gone and you can play poker again. If you win, your

winnings double and you are asked whether you want to play big/small again.

The payoffs on the poker are set against you, odds-wise; the double-or-nothing

game includes a draw, so the odds are against the player there unless you can

time hitting the F key to win more than half the rounds. I haven't managed to

do this, so I don't know if there is anything beyond this, all I know is that

when the table stakes are exhausted, you go back to playing Simon again.

*******************************************************************************

 

KENWOOD @DL de:DG1SFJ 14.01.94 23:38 0 7704 Bytes

9K6Mod fr TH-78E !

*** Bulletin-ID: 0914DB0RBS12 ***

940114/2241z DB0GR , 940109/1721z DB0TEM, 940109/1002z DB0RBS

From: DG1SFJ @ DB0RBS.#BW.DEU.EU

To : KENWOOD @ DL

 

----------------------------------------------------

- 9600 Baud FSK-Modifikation fr das Kenwood TH-78E: -

----------------------------------------------------

 

Hallo Kenwood-Freunde,

hier bekommt Ihr nun die Anleitung zum Modifizieren eures TH-78's, um

damit 9k6 zu machen...

Ich bernehme keine Verantwortung fr die Richtigkeit der in der Anleitung

gemachten Angaben und fr Sch„den die im und am Ger„t durch die Modifikation

entstehen. Die Anleitung ist etwas gr”áer geworden, dafr aber (hoffe ich)

einfacher und auch fr Nicht-Profis (etwas L”terfahrung braucht man schon!!)

verst„ndlich.

1. ™ffnen des Ger„tes:

Alle Stecker incl. Antennenkabel abziehen, die beiden Drehkn”pfe und

danach die Squelch-Regler abziehen. Den Akku entfernen und mit einer

halboffenen Schere oder Zange die beiden Kranz-Muttern an den Squelch-Reglern

rausdrehen. Jetzt f„llt der obere Geh„usedeckel ab, aber auf die beiden

Gummiringe auf den LED's achten, sie fallen leicht runter...

Auf der Rckseite des Ger„tes die 3 Schrauben l”sen, ebenso wie die kleine

Schraube an der Seite beim Antennenanschluá. Vorsichtig das Geh„use

”ffnen. Nun die H„lfte mit der LCD-Anzeige nach links legen, und die

andere nach rechts (wer h„tte dies gedacht :-)

An der Platine mit den Akkukontakten die zwei kleinen Schrauben unten

rechts und links losschrauben, und das Kabel davon abziehen. Diese Platine

k”nnt ihr nun zur Seite legen, und das CTCSS-Modul sollte, falls vorhanden

nun dem Ger„t sanft entnommen werden.

Jetzt nur noch die drei Schrauben auf der Platine l”sen, auf der die Squelch-

Regler sitzen. Dann das geschirmte Kabel, das ebenfalls auf der Platine

sitzt und nachher durch ein Loch in dieser verschwindet, aus der Buchse

rausziehen. Nun die gesamte Platine und die Geh„useh„lfte(LCD) nach rechts

legen, und auf das kleine Kabel von eben und auf das Flachbandkabel

aufpassen...

Damit liegt die Rckseite der Platine mit den Squelchreglern vor euch

bereit fr die Modifikation (letzte M”glichkeit zum Aufgeben des ganzen

Vorhabens ;-)

2. RX-Modifikation:

Auf dieser vorher genannten Platinenseite befinden sich nun 2 Empf„nger-

IC's des Typs MC3372D, je einer fr VHF und UHF. Auf dem Schaltplan

befinden wir uns nun auf der (X57-409X-XX B/4) TR-RX Unit, wobei das

UHF-IC dort IC303 heiát. Dort greift ihr das Diskriminator-Signal

von Pin 9 ab. Um nun den richtigen IC auf der Platine mit dem L”tkolben

zu traktiern, legt ihr diese wie folgt vor euch:

Die Squelch-Regler zeigen nach rechts, ein Flachbandkabel geht von oben

zur Druckguá-Schalenh„lfte des Geh„uses. Nach unten geht das andere

Flachbandkabel Richtung LCD-Geh„useteil. Das UHF-Empf„nger IC liegt nun

weiter rechts, nahe einem IC mit der Aufschrift "4560 246" in der N„he

der Squelch-Regler. Wenn ihr diese habt, so l”tet ihr nun ein Kabel

an Pin 9 an den MC3372D (in diesem Fall oben rechts das letzte Pin). Es

gelten die blichen Tips fr SMD-L”ten (vorher noch mal ben!). Das Kabel

nun um ca. 90 Grad nach rechts biegen, Richtung Squelch-Regler. (solltet

ihr es Richtung Akku biegen, und da auch langfhren, dann bekommt ihr

ein bles Rauschen auf dem gesamten UHF-Band und die Squelch l„át sich

nicht mehr schlieáen...). Abgeschirmtes Kabel ist also anzuraten, ich

habe keines verwendet, allerdings unter Beachtung der Richtung des Kabels

wie oben beschrieben.

Damit ist der Demodulator-Ausgang vom UHF-Empf„nger IC schon mal nach

aussen gelegt und ihr seid (hoffentlich) bereit fr das Abgreifen der

TX-MOD vom Flachbandkabel.

3. TX-Modifikation:

Dieser Teil der "Modifikation" ist eigentlich auch kein Problem, man

sollte nur ruhige H„nde und scharfe Augen haben...

Der Umbau spielt sich wieder in der (X57-409X-XX B/4) TR-RX UNIT ab,

wobei die uns interessierende Leitung vom Mikrofonverst„rker (IC 301)

ber ein Poti (VR302) zum Flachbandkabel links auf dem Schaltplan geht,

welches dort mit B bezeichnet wird. Das Signal liegt von unten aus

gez„hlt an Leitung 11 (MODU) an. Wenn die Platine genauso wie vorher vor

euch liegt, so seht ihr oben ein Flachbandkabel aus Plastik, das in

die Geh„useh„lfte geht, die mit einer Druckguáhaube abgedeckt ist (genau

die mit dem Antennenanschluá), und rechts wieder die Drehregler.

An diesem Flachband-Kabel werden nun von links nach rechts genau 11 in

Worten ELF Leitungen abgez„hlt. Es sieht so aus, als ob keine Leiterbahn

von da aus weiterfhrt, da die Platine aber innen noch eine Schicht hat,

kann man das jetzt noch nicht erkennen. Um die Z„hlrichtung noch mal zu

verdeutlichen: Rechts die Squelch-Regler, links gar nichts, und von

links aus die Leitungen des Flachbandkabels abz„hlen 1,2,3,...,11 und

an dieser Leitung liegt die Modulation fr den VCO. Also genau hier, wo das

Flachbandkabel an der Platine festgel”tet ist, wird nun ein Kabel angel”tet,

aber aufpassen:Erstens h„lt so ein Kunststoff-Flachbandkabel nicht viel

L”terei aus und zweitens ist schnell mal eine danebenliegende Leitung auf

der Platine mitangel”tet (ist mir beinahe passiert...). Das Kabel nun wie

vorher auf dem krzesten Wege nach oben zu den Squelchreglern legen.

4. Letzte Schritte:

So, die typischen 2 Dr„hte sind angel”tet, ist auch keine Brcke

unerwnscht entstanden ?! OK, dann das ganze Ger„t in umgekehrter Reihen-

folge wie beim Zerlegen unter Punkt 1 wieder zusammenbauen, kurzer

Funktionstest, und dann kann das ganze schon an das FSK-Modem angeschlossen

werden. Im TNC-Handbuch sollte man nun nachlesen, wie die Modulation am

besten einzustellen ist (ich habe das mit einem zweiten Empf„nger getan).

Gedanken muá man sich nur noch ber die Verbindung zur Aussenwelt machen,

entweder einen kleinen Platinensteckverbinder (3-polig und einen Pol davon

abfeilen) oder eine 2,5mm Monobuchse (paát wahrscheinlich ebenso nur ab-

gefeilt rein) in den Platz (von oben auf die Funke gesehen) zwischen Antenne

und erstem Drehknopf, weil hier der einzige "groáe" Platz ist. Bei mir h„ngen

zur Zeit einfach die beiden Kabel oben heraus. Wer eine bessere L”sung hat,

sollte mir diese unbedingt schreiben !

5. Ergebnis:

Angeschlossen habe ich mein TH78E an einen TNC 2 H, auf den sich das nun

folgende Ergebnis bezieht:

Die TXDELAY arbeitet mit 10 einwandfrei bei mir, mit 9 wird es etwas weniger

gut, und 8 war bei mir die untere Grenze. Weniger ging absolut nicht, und

ich nehme zur Zeit 10 oder 9.

Die Filter am TNC habe ich noch nicht mit einem Bit-Error-Test geprft,

wenn ihr sowas mal macht wrde ich mich freuen, wenn ihr mir die Ergebnisse

per PR an meine Box DB0RBS schicken k”nntet.

Das TH-78 ist bestimmt nicht ideal fr FSK, aber wenn es wie bei mir das

einzige 9K6-f„hige Ger„t ist, so geht das glaub ich schon. Das ganze habe

ich so seit einem Monat in Betrieb, und es scheint dem Funkger„t nicht

zu schaden. Dankesch”n noch an Andre, DG3SDK, der mir beim Umbau geholfen

hat !

So, und nun viel Spaá mit 9600 Baud PR !

Wenn ihr euren Funk auch mal umgebaut habt, dann schreibt mir doch mal,

damit ich seh, wie es bei euch so geklappt hat ... ihr drft mir

natrlich auch schreiben, wenn es noch Fragen oder Probleme gibt !

Ansonsten 73 und 55 von Jochen, QTH Schwieberdingen, DG1SFJ @ DB0RBS

 

 

(KENWOOD) DD6VD de DB0BRB>

 

From : CT1FMS

To : MODS@WW

Type/status : B$

Date/time : 04-Jan 12:57

BID (MID) : 59707_CT1FMS

Message # : 324913

Title : MODS --> KENWOOD TH78A -1-

Path: !VK7AX!HB9GL!SV1AAW!WB0TAX!KP4IG!EA1RCF!EA8AOP!EA8DW!CT1XK!CT1FOT!

!CT1FMS!

 

From: [email protected]

To : MODS@WW

Subject: Re: Kenwood TH-78 mods / Game

To "open up" as many feature as possible on the TH78A, remove diodes D4 & D5

(located under the copper shield).

This allows the following transmit and receive frequencies

RECEIVE TRANSMIT

--------------- ---------------

VHF BAND

--------

50-135.995 (AM) (NA)

136-179.995 136-179.995

300-399 (AM & FM) (NA)

SUB-UHF

400-511.99 400-511.99

UHF BAND

--------

400-511.99 400-511.99

900-949.9875 (NA)

SUB-VHF

50-179.995 (FM) 136-179.995

 

PERSONAL NOTES:

I found that marine weather reports at 162.40MHz in my area were received much

better on the VHF-SUB band, than on the VHF band. Possible hole?

If you are having problems with intermod, try switching BANDS (ie. USING the

SUB-VHF rather than the VHF etc.)

Cellular Phones are in the 870-890 range, but the frequency increments are

every 30kHz. The TH78A will only increment in 25kHz steps at this frequency

range, so the exact Cellular channel frequency cannot be tuned in (most of the

time).

 

 

 

Removing D4 enables the CROSS-BAND REPEATER function.

CROSS-BAND REPEATER

-------------------

Press [F] key for 1 second, then the [0] (zero) key to turn this function on

and off (MHz dot will flash when in repeater mode).

ANSWERBACK FUNCTION (during paging reception)

---------------------------------------------

Hold down [MHz] key and switch power ON to turn this function ON or OFF.

300 MHz AM/FM SWITCHING

-----------------------

Hold down [VFO] key and switch the power ON to switch between AM and FM

reception.

VHF & UHF EXPANSION

-------------------

Press and hold the [F] key for 1 second, then press the [BAND] key in the

respective bands.

CHANNEL DISPLAY MODE

--------------------

Hold down [3] key and switch the power ON. Channels are displayed by number

instead of frequency. (NOTE: this function only works when Alpha-Numeric

memory is enabled)

CLONE FUNCTION

--------------

Hold down the [0] and switch the power ON.

 

 

*** GAME *** (Available without any modifications)

--------------------------------------------------

Hold down the [M] and [PTT] keys and switch the power ON.

(Be very careful the PTT is depressed or else a memory reset will occur.)

1) Play the memory game.

The radio will beep and display one of the following characters: "1, 2, 3, F"

(top row of buttons). Radio starts with one character and adds a new one on

after every round until 20 characters are reached. You must press the keys in

the same sequence they are displayed. When you can follow the radio for 20

characters, then you will win 100 coins and enter the poker game.

(Note: I am terrible at this game, so I cheated by writing down the character

sequence on paper.)

2) Poker game. (Much more interesting than the first game, IMHO)

Place the bet (1 to 10).

Increase the bet with the up key [2], decrease the bet with the down key [5].

Press [F] to deal the cards.

Cards are (2,3,4,5,6,7,8,9,+,J,K,Q,A NOTE: 10 = "+")

Press [PTT] to see the suits.

Press numbers 1 through 5 to change the respective cards.

Press [F] to deal the new cards.

If you win any amount, you can bet for double or nothing.

Press [F] to play "BIG or SMALL".

Press [LOW] to keep your winnings.

BIG or SMALL

------------

A random card will be chosen.

Push [2] (big) if you think this card is going to be larger than 8.

Push [5] (small) if you think this card is going to be less and 8.

(if an 8 is drawn, then a tie occurs, and you neither win nor lose)

Press [F] to draw the random card.

You either double your winnings or lost it all.

Press [F] to continue playing Big or Small.

Press [LOW] to keep winnings and continue playing poker.

Push the [LAMP] key to exit the game mode.

Note: While in game mode, receive functions still operate!

----------------------------------------------------------

 

 

Best 73. Paulo, [email protected]

 

 

 

--- End of messsage #324913 to MODS from CT1FMS ---

(1) TA2EM BBS (H for help) >

From : CT1FMS

To : MODS@WW

Type/status : B$

Date/time : 04-Jan 12:57

BID (MID) : 59708_CT1FMS

Message # : 324908

Title : MODS --> KENWOOD TH78A -2-

Path: !VK7AX!VE1SMU!N5VDA!N9DBX!N7NEI!KL7IFW!N4ZKF!KP4IG!EA1RCF!EA8AOP!EA8DW!

!CT1XK!CT1FOT!CT1FMS!

 

 

 

 

From: [email protected]

To : MODS@WW

Subject: TH78A mod file, crossband repeat, extended RX/TX, cloning

"TH-78A Modification File"

 

Subject: TH-78A Modification File

Owner assumes all responsibility for modifying or using these

modifications!.

The following mods will provide for Crossband Repeat and extended

receive and transmit on the Kenwood TH-78A HT.

I believe other functions are also enabled by these mods. which I

have not found yet but I will update the file as news progresses.

Diode #4- Crossband Repeat

Diode #5- Extended Receive and out of band Transmit.

Remove all screws and open radio as explained in the Kenwood manual

for installing the memory expansion module.

On the back cover you will find the memory expansion module socket

and a copper shield to the upper left corner of it.

Under this shield their will be a row of SMC diodes which are

unmarked in a vertical configuration to the lower right portion

covered by the shield.

#1 Remove the shield at its four corners with a solder sucker and

SMALL! iron.

#2 Carefully count down from the 1st diode in the row to the fourth

one and remove for crossband repeat.

HINT: I found if you BRIEFLY touch the iron to the right side lead

while gently pulling up on the SMC diode it should completely come

off without needing to apply heat to the other side and further

risk board damage.

I used a pair of right angle surgical tweezers for this.

#3 Just as above you may remove the fifth diode to preform the

extended receive and transmit modification.

#4 Reset the CPU (yes you will loose all of your programed

memories! argh!) by pressing Function for more than one second and

then "0".

YOU HAVE NOW COMPLETED THE MODIFICATIONS!

#5 For 800Mhz go to the UHF band with the band switch and press

Function for more than one second quickly following with a press of

the Band switch again. 8---.-- will appear.

#6 For 300MHz go to the VHF band and repeat as above. Original

bands are restored by repeating the "F Band" sequence.

MY observations... All original functions have maintained the

same which is great. Aircraft band which was accessible before the

mod remains with the same characteristics. It seems that VHF-High

band has improved a bit on sensivity where it was dead as a dog

before the mod (above 155.000MHz) but the 162.000 MHz band where

weather radio is is still a bit deaf for reception at any distance

but about 20 Miles. This depends on your (or my) terrain and

transmitter output power.

On UHF all public safety frequencies up to about 500 MHz seem to

come in well but sensivity greatly drops from there (we really

can't ask for more). Frequencies can be programed in up to the

920MHz ham band but I have no way of measuring sensivity. 800MHz

works but the signals are very weak, you must be near the

transmitter for reception. Assuming you are in the town or city

where the transmissions originate it should work.

Transmit is enabled up to and incl. 500MHz but after testing this

on a frequency counter I find that a signal is only generated to

about 490 MHz, even though the trans. LED shows output in the

higher frequencies.

Crossband repeat seems to work fine but the audio is unacceptable

for use, BE AWARE the radio gets HOT! Prolonged use or use on a

busy frequency would not be recommended. Also remember this is a

dual band HT please use a proper antenna while in this mode to

avoid a high SWR, we should all know better... Right?

After first booting up the CPU in the mod I found that the message

screen showed "Cloning" so it seems that this radio now has cloning

capabilities. After searching I have found that holding the "0" key

and powering up the radio will display the clone feature, see below

for further explination.This leads me to believe that this HT may

have some more "Hidden" features that I am trying to find, some may

be useful.

Thanks to Gary KC8UD who sent me the following via packet .....

CLONING:

The TH-78 can be cloned without cloning cables or special equipment. It is done

entirely with RF, and, in fact, can be transmitted over the air, and even via

repeaters. This may be extremely useful for those users who do not have

the patience to program their own radios themselves. This application would

also be useful for clubs and user groups. (However, this can take as long as

50 minutes with the ME-1 expansion module. It is recommended that a dummy

load be used to prevent unwanted QRM.)

(1) Both radios must be on the same frequency.

(2) Activate both radios by pressing the "0" key while turning the power on.

The radios will display CLONE.

(3) Now, click the PTT of the "master" radio. The radio will transmit in the

conomy low power mode. This may take about 4 minutes for fifty channels.

hen the data has been transferred, both radios will revert back to the

riginal frequency.

(4) Turn both radios off and then on again. They will now operate normaly

while the slave radio has the same memory contents as the master radio.

FREQUENCY EXPANSION

(1) You can receive from 340 - 399.987 Mhz FM by removing chip diode D8 on the

ontrol unit. To access this function, press the [F] key for one second, and then

the [LOW] key. This toggles between AMATEUR, AIR band (AM) and 360 Mhz.

AM and FM modes are selected automatically, depending on frequency.

** Since "F" for a second and "Low" toggles the power output, I wonder **

There is also a couple of arcade type games on the TH-78A. To start the

game you pres and hold [PTT] and [M] keys while turning the unit on. The first

game is a follow me type game. The radio beeps and shows a sequence of

numbers flashing on the screen. You have to match the same sequence on the

tone pad. Each time the sequence gets longer by one number. You have to

keep remembering the sequence as one gets added each time. Once you get to

a certain high score on that game, it breaks into a poker type game. To exit

the game mode press the LAMP key at any time. The receiver still works in

the game mode and you can adjust volume but no other features.

RG> The games seem to work fine and it is interesting that they have

inserted that into the programing of the chips. Does anyone know of any further

features in the radio be it games or radio functions.

=============================================================================

Note: I haven't tried or verified this, proceed at your own risk. And

do not transmit outside of legal bands!

 

 

Best 73. Paulo, [email protected]

 

 

Kenwood TH-77 Extended frequency coverage and dual-band repeater

Kenwood has made this radio compatible with the new ICOM S-Series radios

from what I can tell. It has DTSS (Dual Tone Squelch System) which means

that your radio will not break squelch until it hears a particular

sequence of three DTMF tones (ICOM has this also and they call it

Coded Squelch which also use three tones). The TH77A also has a paging

function that works *exactly* like the ICOM paging. You program the

radio with a personal 3 digit DTMF code and someone pages you by

transmitting YOUR 3 digit code, followed by a * character and then

their own 3 digit code. The ICOM will start to ring to let you know

that you have been paged and display the 3 digit code of the person

that has paged you. The TH77A will beep once and open squelch as

long as the person that paged you does not drop carrier (I prefer

the ICOM method for this part, but there is a work around that I

will mention in a bit). One thing the TH77A does at this point is

bring up a timer so you know how long its been since you've been

paged. Maximum time is 99 hours and 99 minutes. Let's see if your

battery can hold out that long! The workaround so the TH77A will

ring, rather than just beep and open squelch is to put the radio

in the pager mode AND also put it in Tone Alert. When you get

paged... the radio will "beep beep (pause) beep beep" five times

and start up the timer. Kenwood has provided two different types

of BEEPS for you. The second type is to ring like an electronic

telephone. This one *REALLY* sounds nice!! For those of you that

like autodial memories, there are 10 memories that can store 15

characters each. There are 40 regular frequency memories in this

radio and you can make them all UHF if you like (no restriction).

NOW! On to the *EXTRA* capabilities (there are other BASIC functions

that I didn't mention, those were just the highlights).

After making a few modifications to this radio, you can get it to

do the regular stuff that the IC24AT will do, such as AM aircraft,

expanded UHF (400-512 depending on PLL lock) and 800-950 (again,

depending on PLL lock) in addition to cross band repeat.

HOW DO YOU DO THIS!?

-- -- --

|| || ||

/ \ / \ / \

=========================-

| |

| \-\

| |

| /=====----\ |

| | | |

| | | |

| | | |

| | | |

| \=====----/ |

| |

| -- -- -- |

| || || <================== REMOVE THE RIGHT ONE

| -- -- -- | FOR AM/800-950 RX.

| -- | REMOVE BOTH TO ALSO

| || -- -- -- -/ GET EXTENDED TX.

| -- || || || /

| -- -- -- |

| |

| /==========--\ |

| | | |

| | | |

| | | |

| | | |

| | | |

| \==========--/ |

| |

| |

=========================-

Layout shown with electrolytic capacitor C124 removed

The best way to do this is to heat up both sides of the resistor and

push it out of the way with something small. At least this was the

best way for me! Once it's out, put the capacitor back in place and

close it up. (Put the green wire back also, if you are making the

out of band TX mod too!)



 

KENWOOD TH-75A MODS

I have a couple of mods that you may or may not have. For the TH-75A MARS/CAP

mod, removing D4 will allow TX across entire tuning range, except that

actual TX range will be limited by tuning of the PLL.

For the TM-731A, there is a "Beyond MARS/CAP transmit Modification". It

provides TX from 136 to 174 and 400 to 500 MHz. Again, actual TX range limited

by PLL tuning. If you don't already have this and would like it, I'll

send a copy if you furnish me your address. It involves cutting R25 on the

control unit, and installing a jumper (diagram required to locate position),

then two resets in a row.

 

From: WA6TKV

The Kenwood approved MARS mod for the TH-75A is very

simple. Remove the 3 exterior screws. There are 4 screws

where the battery pack slides on. Remove the 2 screws toward

the face of the radio. You now have access behind the front

panel. You will see a green wire near a square chip. Cut the

wire. You will now have transmit from 142-152 and receive from

136-174. Transceive from 420-450. Although you can actually

key in 385-512.

This is truly a fantastic radio! You can take the mod two

steps further. You will definitely need a service manual and a

very delicate touch. (Not for the weak!) Locate and remove D4.

It is in the same vicinity of the green wire. The radio will

now transceive from 136-174, some VCO adjustment may be required

for the entire range. It is also now capable of transceiving

from 385-512. The UHF VCO's have approximately a 50 MHz band-

width so you will only get a 50 MHz wide portion of 385-512.

The second step is adjusting the VCO's. There are separate

adjustments for transmit and receive for both VHF and UHF.

This calls for complete dis-assembly of the radio. Refer to

your service manual.

I have found these mods extremely valuable. Now I have

a dual band ham rig and a police scanner in one. Have fun and

please use EXTREME caution in transmitting only on your amateur

and MARS frequencies.



 

KENWOOD TH45AT MODS & INFO

Subject: KENWOOD TH-25/45 OUT OF BAND MODIFICATIONS

Here are some mods for the TH-25AT and the TH-45AT. Please

note that I do not encourage transmitting on a frequency for which you

do not have a license, nor do I encourage transmitting on a non-amateur

frequency without FCC type accepted equipment (in the United States).

First let me recommend that you buy the service manuals for these

radios. The service manual is not expensive (about $15 I think) and it

will greatly help you in performing these modifications.

Look at the schematic for your radio. In the lower left hand corner is

an IC labled IC2. This is an ASIC microprocessor. At the lower right

hand corner of this uP are several diodes and pull-up/pull-down

resistors. They are D4, D3, R19, R18, R28, R20, R21, R22, R25, R26, and

a couple of resistors that are not even on the schematic that attach to

B2 (pin 51 on IC2) and B3 (pin 50 on IC2). The TH-45AT schematic shows

R23 on the ASIC uP pin B2.

The schematic for the TH-25AT shows:

R18-R21 R25 R26,27 R28 R36

TH-25A M,M2 -12 O X X X X

TH-25A M3,M4,X -23 O X X O X

TH-25AT K -11 O O X X X

TH-25AT M,M2 -12 O X X X X

TH-25E T -52 X X O O O

TH-25E W -62 X O O O O

And the schematic for the TH-45AT shows:

R19-R21 R22 R23 R25 R26,27 R28 R36

TH-45A M1,M2,X -21 O O O X X O X

TH-45A M3,M4 -22 O X O X X X X

TH-45AT K -10 O X O X X O X

TH-45AT M1,M2 -21 O O O X X O X

TH-45AT M3,M4 -22 O X O X X X X

TH-45E T -51 X O X X O X O

TH-45E W -61 X O X O O O O

where O means USED, and X means NOT USED.

 

On the TH-25AT:

(All frequencies given in MHz.)

R22 in

R28 out

This is how the radio is delivered in the USA. TX 144-1, 141-163

(I think).

R22 out

R28 in

The radio tunes from 142-151. This may be the modification given

to US MARS members. I don't remember where the unit will transmit. It

may or may not transmit outside the range from 144-148.

R22 in

R28 in

The radio tunes only from 144-148.

R22 out

R28 out

Frequencies may be selected from 100-200 MHz (on the display only - your

PLL will not lock up in this entire range). In addition, TX is possible

where your PLL locks up.

R25 out

Removing R25 disables automatic offset selection.

R23 and R24 are used for selecting the step size for tuning. I can't

remember which positions are for which step sizes, and alas I didn't

write down what I found. If you want to play with this, go ahead.

On the TH-45AT:

(All frequencies are given in MHz.)

R18 in

R28 in

This is how the radio is delivered in the USA. The radio covers

438-450 MHz.

R18 in

R20 out

The radio is prohibited from tuning outside 440-450 MHz.

R18 out

R28 in

The radio will only tune from 215-230 MHz. Note that the PLL would not

lock up! (What did you expect?) Could it be possible that Kenwood

originally planned a 220 version of this radio, but then scrapped their

plans?

R18 out

R28 out

The radio will tune from 200-500 MHz (on the display only - your PLL

will not lock up over this entire range). Transmitting is possible

anywhere your PLL will lock up.

I have found a quick and easy way to retune your PLL (in the TH45-AT)

with a minimum of test equipment. All you need is a scope and a small

tuning tool. First, take off the battery pack holder plate. Then,

remove the silvery sticker covering the tuning pot access holes. If the

radio is positioned on its back, with the top folded over so that the

touch tone pad is also facing down, the test point you want (TP1) is on

the bottom half of the radio, near the center (left to right), and close

to the battery; the tuning pot you want (TC1) is on the bottom, and

closest to the PTT switch. Under no circumstances change the tuning of

TC51. This is used to calibrate the output of the radio with the

display the radio is giving; you don't want to mess with it. Once

again, the Service Manual makes it very clear where these points are, if

you are having trouble with my descriptions. On with retuning the PLL.

With the radio on, and receiving, monitor the voltage and the waveform

on test point TC1.

Tune the radio DOWNWARDS in frequency until the PLL

unlocks. Note that the radio will beep when this happens, and the

waveform on TP1 will change. Tune the radio about 1 MHz higher so that

the PLL locks up again, and note the voltage on the testpoint, TP1.

Now, tune the radio to the LOWEST frequency that you want to be able to

receive. Adjust TC1 until the voltage on the test point TP1 is the same

as what was noted earlier. Button the radio back up, and you're

done. You will not be able to tune the PLL to any range you want.

There are limits. On my radio, I have been able to retune the radio so

that I can recieve from 439.2-468.6 MHz with a set of batteries fresh

out of the charger. The tuning range will probably diminish as the

battery voltage decreases. I have not retuned the PLL on my 2m HT, but

I'd imagine the same technique will prove fruitful.

I may have some more information on these radios someplace. If I can

find it, I will add to this posting, and post it again with the updated

information.

 

Some of the above codes are:

K USA

T England

X Australia

M Other Areas

These components are found on the flexible circuit board under the

display. To get to them, take the radio apart. Some unsoldering of

obvious grounding wires may be necessary. You will see where the

flexible circuit board plugs into a socket on the main circuit board.

Before unplugging it, make sure you know what's in the memories, because

they will be lost. Unplug the flexible circuit board and unfold it so

that the components are accesable. One of the fold-out parts of the

flexible board will look something like this:

 

+----------------+

! R R R D3 R R !

! 2 2 2 7 2 !

! 5 3 2 1 !

! !

! R O O R20! The O's are solder pads.

! 2 O O R19!

! 6 O O R18!

! O O R28!

! !

! R !

! D4 6 !

! +-------+

! !

! !

The fold out board is actually square, but with only characters for

graphics, I couldn't draw it that way.

On both radios, R36 is for the European tone burst to "whistle up"

repeaters.

On both radios, D4 is for selecting the type of display. With D4 in,

the display is normal. With D4 removed, the display is a channel

display.

D3 is for selecting VHF or UHF. With D4 in, the radio thinks its a VHF

radio. With D4 removed, the radio thinks its a UHF radio. Don't change

this on your radio.



 

TH26AT

EXTENDED TX COVERAGE ON THE KENWOOD: TH-26AT/TH-45AT/TH-75A HT's

================================================================

 

On the three above units a jumper wire controls the TX frequency coverage. By

removing the jumper you will extend TX from 142-152Mhz. By removing a diode

you can extend the TX coverage to the limits of the VCO. Both the jumper wire

and the diode are located on the "CONTROL UNIT". On the TH-26AT this is just

a bare jumper wire, TH-45AT ???, TH75A it is a green wire labled W1. Removing

or lifting D4 on the TH-75A extends TX from 136-174Mhz and 335-512Mhz. On the

TH-26/TH-46 models this would be 136-174Mhz and 335-512Mhz respectivly.

 

Thanks to Ray WA6TKV @ N6IIU for TH-75A mod.

TH-26A/TH-26AT/TH-26E, TH46A/TH-46AT/TH-46E mod Doug VE3IYB @ VE3EUK



 

MOD TO OPEN TX ON THE

KENWOOD TH-2600-A

1. TO ACCESS THE 2600 LOOSEN THE TWO LARGE SCREWS ON THE SIDES OF THE UNIT

WITH A COIN.

 

2. REMOVE THE 3 VERY SMALL PHILLIPS HEAD SCREWS ON THE BACK-SIDE OF

THE UNIT

 

3. REMOVE THE BATTERY.

4. IN THE BASE OF THE UNIT YOU WILL SEE FOUR PHILLIPS HEAD SCREWS

REMOVE THE TWO THAT HOLD DOWN THE FRONT OF THE UNIT (SPEAKER SIDE)

5. INSERT SCREWDRIVER INTO BASE & TWIST --YOU WILL HEAR A "POP" AS

THE TWO HALVS SEPARATE.

6. CAREFULLY LIFT FRONT & LET IT TURN TO THE RIGHT, AS THERE IS A

RIBBON CONNECTION BETWEEN THE FRONT COVER & THE CHASSIS.

7. IN THE LOWER RIGHT HAND CORNER OF THE P.C. BOARD YOU WILL SEE

A ROW OF DIODES ON END (ABT 7), SNIP THE TOP TWO. (THEY MAY

ALREADY HAVE A SOLDER JOINT, AS THESE ARE USED IN BENCH TEST)

8. NOTE: THESE ARE DIODES D-32 & D-33 THE BOARD YOU ARE WORKING ON

IS X55-1380-10 A/2

9. REVERSE THE PROCESS, & THERE YOU HAVE IT......

 

KENWOOD TH25AT MODS & INFO

The Mars & Cap mod for the Kenwood TH-25AT is to remove resistors R18-21.

They are located on a panel under the display. This one is a real pain to

access but this mod gives transmit coverage from 140-163 Mhz.

 

*************************************************************

TH-25AT MARS/CAP MODIFICATION

 

The following modification will allow the TH-25AT to transmit

from 141.000 Mhz to 162.995 Mhz. Specifications are guaranteed

for the Amateur band only. The transceiver may require

realignment of the PLL circuits.

 

1. Disconnect the battery pack and antenna.

 

2. Remove the VOLUME, SQUELCH, and TUNING control knobs by

pulling them straight up from the top panel.

 

3. Using a 7mm spanner wrench, remove the nut from the VOLUME

control and the nut from the TUNING control.

 

4. Remove one screw located by the PTT switch.

 

5. Remove one screw located by the speaker jack.

 

6. Remove two screws from the battery terminal plate.

7. Carefully pull the front panel up from the transceiver (do

not break the wires connected between the front panel and the

body of the transceiver). Lay the front panel to the side of

the transceiver (keep track of the PTT and F.LOCK covers if

they come off).

 

8. Gently lift the top panel from the transceiver by pulling it

forward and then up (the "O" ring on the BNC connector will

produce some tension).

 

9. Rotate the top panel toward the front of the radio to expose

the 3/4 x 3/4 inch board.

 

10. Using a 45 watt (or less) soldering iron that has an isolated

or grounded tip, unsolder and remove chip resistors R19 - 21

from the Control Unit (X53-3080-02).

 

11. Carefully assemble the transceiver by reversing steps 1-9.

Pull the BNC connector "O" ring up a little before installing

the top panel.

 

12. Reset the microprocessor by the following the preocedure in

the instruction manual (page 16) called CLEARING ALL MEMORY.

 

 

********************************************************

to unlock the kenwood 25at.......

take the rig apart and find chip resistors r-19 r-20 r-21..

cut them, reset the cpu, put back togeather.... thats all

 

*************************************************************

Subject: KENWOOD TH-25/45 OUT OF BAND MODIFICATIONS

Here are some mods for the TH-25AT and the TH-45AT. Please

note that I do not encourage transmitting on a frequency for which you

do not have a license, nor do I encourage transmitting on a non-amateur

frequency without FCC type accepted equipment (in the United States).

First let me recommend that you buy the service manuals for these

radios. The service manual is not expensive (about $15 I think) and it

will greatly help you in performing these modifications.

Look at the schematic for your radio. In the lower left hand corner is

an IC labled IC2. This is an ASIC microprocessor. At the lower right

hand corner of this uP are several diodes and pull-up/pull-down

resistors. They are D4, D3, R19, R18, R28, R20, R21, R22, R25, R26, and

a couple of resistors that are not even on the schematic that attach to

B2 (pin 51 on IC2) and B3 (pin 50 on IC2). The TH-45AT schematic shows

R23 on the ASIC uP pin B2.

The schematic for the TH-25AT shows:

R18-R21 R25 R26,27 R28 R36

TH-25A M,M2 -12 O X X X X

TH-25A M3,M4,X -23 O X X O X

TH-25AT K -11 O O X X X

TH-25AT M,M2 -12 O X X X X

TH-25E T -52 X X O O O

TH-25E W -62 X O O O O

And the schematic for the TH-45AT shows:

R19-R21 R22 R23 R25 R26,27 R28 R36

TH-45A M1,M2,X -21 O O O X X O X

TH-45A M3,M4 -22 O X O X X X X

TH-45AT K -10 O X O X X O X

TH-45AT M1,M2 -21 O O O X X O X

TH-45AT M3,M4 -22 O X O X X X X

TH-45E T -51 X O X X O X O

TH-45E W -61 X O X O O O O

where O means USED, and X means NOT USED.

Some of the above codes are:

K USA

T England

X Australia

M Other Areas

These components are found on the flexible circuit board under the

display. To get to them, take the radio apart. Some unsoldering of

obvious grounding wires may be necessary. You will see where the

flexible circuit board plugs into a socket on the main circuit board.

Before unplugging it, make sure you know what's in the memories, because

they will be lost. Unplug the flexible circuit board and unfold it so

that the components are accesable. One of the fold-out parts of the

flexible board will look something like this:

 

+----------------+

! R R R D3 R R !

! 2 2 2 7 2 !

! 5 3 2 1 !

! !

! R O O R20! The O's are solder pads.

! 2 O O R19!

! 6 O O R18!

! O O R28!

! !

! R !

! D4 6 !

! +-------+

! !

! !

The fold out board is actually square, but with only characters for

graphics, I couldn't draw it that way.

On both radios, R36 is for the European tone burst to "whistle up"

repeaters.

On both radios, D4 is for selecting the type of display. With D4 in,

the display is normal. With D4 removed, the display is a channel

display.

D3 is for selecting VHF or UHF. With D4 in, the radio thinks its a VHF

radio. With D4 removed, the radio thinks its a UHF radio. Don't change

this on your radio.

On the TH-25AT:

(All frequencies given in MHz.)

R22 in

R28 out

This is how the radio is delivered in the USA. TX 144-1, 141-163

(I think).

R22 out

R28 in

The radio tunes from 142-151. This may be the modification given

to US MARS members. I don't remember where the unit will transmit. It

may or may not transmit outside the range from 144-148.

R22 in

R28 in

The radio tunes only from 144-148.

R22 out

R28 out

Frequencies may be selected from 100-200 MHz (on the display only - your

PLL will not lock up in this entire range). In addition, TX is possible

where your PLL locks up.

R25 out

Removing R25 disables automatic offset selection.

R23 and R24 are used for selecting the step size for tuning. I can't

remember which positions are for which step sizes, and alas I didn't

write down what I found. If you want to play with this, go ahead.

 

On the TH-45AT:

(All frequencies are given in MHz.)

R18 in

R28 in

This is how the radio is delivered in the USA. The radio covers

438-450 MHz.

R18 in

R20 out

The radio is prohibited from tuning outside 440-450 MHz.

R18 out

R28 in

The radio will only tune from 215-230 MHz. Note that the PLL would not

lock up! (What did you expect?) Could it be possible that Kenwood

originally planned a 220 version of this radio, but then scrapped their

plans?

R18 out

R28 out

The radio will tune from 200-500 MHz (on the display only - your PLL

will not lock up over this entire range). Transmitting is possible

anywhere your PLL will lock up.

I have found a quick and easy way to retune your PLL (in the TH45-AT)

with a minimum of test equipment. All you need is a scope and a small

tuning tool. First, take off the battery pack holder plate. Then,

remove the silvery sticker covering the tuning pot access holes.

If the

radio is positioned on its back, with the top folded over so that the

touch tone pad is also facing down, the test point you want (TP1) is on

the bottom half of the radio, near the center (left to right), and close

to the battery; the tuning pot you want (TC1) is on the bottom, and

closest to the PTT switch. Under no circumstances change the tuning of

TC51. This is used to calibrate the output of the radio with the

display the radio is giving; you don't want to mess with it. Once

again, the Service Manual makes it very clear where these points are, if

you are having trouble with my descriptions. On with retuning the PLL.

With the radio on, and receiving, monitor the voltage and the waveform

on test point TC1. Tune the radio DOWNWARDS in frequency until the PLL

unlocks. Note that the radio will beep when this happens, and the

waveform on TP1 will change.

Tune the radio about 1 MHz higher so that

the PLL locks up again, and note the voltage on the testpoint, TP1.

Now, tune the radio to the LOWEST frequency that you want to be able to

receive. Adjust TC1 until the voltage on the test point TP1 is the same

as what was noted earlier. Button the radio back up, and you're

done. You will not be able to tune the PLL to any range you want.

There are limits. On my radio, I have been able to retune the radio so

that I can recieve from 439.2-468.6 MHz with a set of batteries fresh

out of the charger. The tuning range will probably diminish as the

battery voltage decreases. I have not retuned the PLL on my 2m HT, but

I'd imagine the same technique will prove fruitful.

I may have some more information on these radios someplace. If I can

find it, I will add to this posting, and post it again with the updated

information.



 

TH22AT

copied from the Internet Usenews:

From: [email protected] (Brent Forsberg)

Newsgroups: rec.radio.amateur.equipment

Subject: TH-22AT Beyond MARS ModificationDate: November 17, 1993

This procedure will expand the transmit capabilities from 136.000 MHz to

173.995 MHz.

PROCEDURE:

This modification is provided "as is" and is subject to change witwitwithout no

tice.

no warranty of any kind with regard to this modification procedure, including,

but not limited to, the implied warranties of merchantability and fitness for a

particular purpose. shall not be liable for any error or for incidental or

consequentialdamage in connection with the furnishing, performance, or use of

this modification procedure.

1. Turn off the power.

2. Remove the battery pack.

3. Remove the two long screws from the rear of the rADIO CASE.

4. Remove the two knobs from the top of the unit.

5. Remove the rubber top panel.

6. Squeeze the bottom of the front panel together and gently separate the two

case halfs. Use caution so that you do not damage the thin ribbon cable

connecting the front panel to the main unit.

7. Remove diode D208. Located on the circuit board behind the front panel.

See diagram.

8. P P Place the diode you just removed [D208] in the location shown for (D212

) and

solder in place. Observe proper polarity. The diode should face the same

direction as diode D210 and D211.

9. Reverse steps 1 - 6 to reassemble.

10. Reset the microprocessor.

CAUTION: This modification requires soldering equipment rated for CMOS type

circuits. It also requires familiarity with surface mount soldering techniques

.

If you do not have the proper equipment or knowledge do not attempt this

modification yourself. Seek qualified assistance.

Time required for this modification is 30 minutes or less.

! ======== W201

!

! ======= W202

!

! ______________

-------------------! ! [D206] [D210]

! !

thin ! CN203 ! [D207] [D211]

ribbon ! Q

! ! [D208] (D212)

! !

! ! (D213)

! !

! !

! !

-------------------!______________! ____________

! _________________! !

! ! ! !

! ! SP ! MIC !

!_________________________!_______________!____________!______

! ! ! !

X57-4370-11 (B/4)

 

 



 

th225 144 - 165 TX/RX MOD

TO OPEN YOUR TH-205,215,OR 225 ALL YOU HAVE TO DO IS TAKE OUT THE SCREWS

ON THE BACK, AND GENTLY OPEN UP THE FRONT OF THE UNIT...LOCATE THE OBVIOUS

4 JUMPER BRIDGES ON THE PC BOARD. THE BRIDGES ARE NUMBERED J-1, J-2, J-3,

AND J-4..JUMPER J-3 HAS ALREADY BEEN CUT...CAREFULLY SNIP JUMPERS J-1 AND

J-2 AND EVER SO SLIGHTLY SEPERATE THE SNIPPED BRIDGES TO INSURE NO-CONTACT

BETWEN THE POINTS.. REASSEMBLE THE UNIT..LOOK AT YOUR INSTRUCTION MANUAL

AND RESET THE MICROPROCESSOR..THE MOD WILL NOT WORK UNTIL YOU RESET THE MPU...

THE INFO. FOR RESET IS NEAR THE BACK OF THE MANUAL..AFTER THAT THE UNIT IS

WIDE OPEN TO OPERATE BETWEEN 144 TO 165.



 

From : PB0AFK

To : MODS@WW

Type/status : B$

Date/time : 20-Dec 08:50

BID (MID) : 21767-PB0AFK

Message # : 322104

Title : KENWOOD TH2600A

Path: !I6BNW!IK6PYS!IK6RUY!IW0QMN!WB0TAX!N4ZKF!N4ZKF!KA3FMO!SR9ZAA!SR6DJG!

!DB0GRL!SP6KBL!OK0PHL!OK0PPL!DB0RGB!DB0MAK!DB0SON!DB0ERF!DB0SHG!DB0HSK!

!PI8DRS!PI8ZWL!PI8APD!PI8GCB!PI8WFL!PI8MBQ!PI8VNW!

From: PB0AFK@PI8VNW.#ZH2.NLD.EU

To : MODS@WW

* TstHost for Dos v1.43b - registered to PB0AFK *

* UTC diff: -1, Local time: 18-12-1998 00:35:45 *

* The world according to Garp and PB0AFK(Henk) *

* Msg:41771 Bid:21767-PB0AFK

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĶToplogo creator (c) 1997-1998 by PD0OLNºÄÄÄÄÄÄ

 

Subject: MOD TO OPEN TX ON THE KENWOOD TH-2600-A

1. TO ACCESS THE 2600 LOOSEN THE TWO LARGE SCREWS ON THE SIDES OF THE

UNIT WITH A COIN.

 

2. REMOVE THE 3 VERY SMALL PHILLIPS HEAD SCREWS ON THE BACK-SIDE OF

THE UNIT

 

3. REMOVE THE BATTERY.

4. IN THE BASE OF THE UNIT YOU WILL SEE FOUR PHILLIPS HEAD SCREWS

REMOVE THE TWO THAT HOLD DOWN THE FRONT OF THE UNIT (SPEAKER SIDE)

5. INSERT SCREWDRIVER INTO BASE & TWIST --YOU WILL HEAR A "POP" AS

THE TWO HALVS SEPARATE.

6. CAREFULLY LIFT FRONT & LET IT TURN TO THE RIGHT, AS THERE IS A

RIBBON CONNECTION BETWEEN THE FRONT COVER & THE CHASSIS.

7. IN THE LOWER RIGHT HAND CORNER OF THE P.C. BOARD YOU WILL SEE

A ROW OF DIODES ON END (ABT 7), SNIP THE TOP TWO. (THEY MAY

ALREADY HAVE A SOLDER JOINT, AS THESE ARE USED IN BENCH TEST)

8. NOTE: THESE ARE DIODES D-32 & D-33 THE BOARD YOU ARE WORKING ON

IS X55-1380-10 A/2

9. REVERSE THE PROCESS, & THERE YOU HAVE IT......

73 de Henk

Pc 486dlc 5MB Svga 210MB Hdd Svga Cdr-player Tnc AEA Pk-88

Hp 100Lx PortFolio Psion user / TelephoneCard Collector /Jimi Hendrix devotee

 

'I use NO invisible TAG-line. Do NOT send me 10dollars for a invisible one'

Created by Mes_filter v1.06c

 

--- End of messsage #322104 to MODS from PB0AFK ---

 

From : PB0AFK

To : MODS@WW

Type/status : B$

Date/time : 20-Dec 12:18

BID (MID) : 21768-PB0AFK

Message # : 322125

Title : KENWOOD TH215

Path: !I6BNW!IK6PYS!IK6RUY!IW0QMN!WB0TAX!N5VDA!LX0IST!SR9DIP!SR6DOP!SP6KBL!

!OK0PHL!OK0PPL!DB0RGB!DB0MAK!DB0ERF!DB0HSK!PI8DRS!PI8ZWL!PI8APD!PI8GCB!

!PI8WFL!PI8MBQ!PI8VNW!

 

 

 

From: PB0AFK@PI8VNW.#ZH2.NLD.EU

To : MODS@WW

* TstHost for Dos v1.43b - registered to PB0AFK *

* UTC diff: -1, Local time: 18-12-1998 00:35:46 *

* The world according to Garp and PB0AFK(Henk) *

* Msg:41772 Bid:21768-PB0AFK

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĶToplogo creator (c) 1997-1998 by PD0OLNºÄÄÄÄÄÄ

KENWOOD TH-215A handheld transceiver out-of-band modification:

1. Remove two screws from belt clip

2. Remove 4 screws from back of radio

3. Slide front assembly off

4. Locate set of 4 jumpers:

(top front inside)

+--------------------------------------+

| |

| |

| +--------+ |

| | | |

| | | |

| +--------+ |

| |

| +--------+ |

| | | |

J4: intact | J4 o---o | | |

J3: cut | J3 o) (o +--------+ |

J2: cut | J2 o) (o |

J1: cut | J1 o) (o |

| |

| |

| |

| SPKR |

| |

| |

| mic |

| |

+--------------------------------------+

5. Reassemble radio.

6. Reset microprocessor: Turn radio on while simultaneously pressing

both _F_ key and _ENTER_ key.

--

DISCLAIMER: I do not own a TH-215A and have not verified the above

information. Hopefully, the modified frequency range includes 162 MHz

weather-broadcast freqs. Remember, it is ILLEGAL to transmit outside

the ham band with non-FCC-type-accepted equipment, even if you are

licensed to use such frequencies.

73 de Henk

Pc 486dlc 5MB Svga 210MB Hdd Svga Cdr-player Tnc AEA Pk-88

Hp 100Lx PortFolio Psion user / TelephoneCard Collector /Jimi Hendrix devotee

 

'I use NO invisible TAG-line. Do NOT send me 10dollars for a invisible one'

Created by Mes_filter v1.06c

 

 

 

 

--- End of messsage #322125 to MODS from PB0AFK ---

 

KENWOOD TH215 MODS & INFO

Subject: a TH215 no audio fix

PROBLEM:

In a sample population of about 60 amateurs in this town, three of us

own Kenwood TH-215A HT's, all purchased separately at different times

from different sources....

ALL THREE have developed an audio problem in the last eight months:

the audio (both from the microphone and from the keypad) simply

disappears at unpredictable intervals. And all three can be "fixed"

by WHACKING the HT with the palm of one's hand--until it happens again.

A POSSIBLE FIX:

You guys may be in luck, since I fixed mine -- I have the service manual

and decided to jump in (I had upgraded the software and you have to pull the

unit completely open to do it -- ). Anyway, I was using the rig one day and

the next -- no audio -- just a slight noise that appeared to be white noise

from the final audio buffer. When plugging in the speaker mike -- same

problem. Touch the TTPAD and get your ears blown away -- I think beep also

worked. Kenwood had no knowledge of previous problems.

I had to rig-up a jumper ribbon cable so I could lay the rig out for

testing and immediately checked the input audio to the volume control.

No problem -- but there was nothing coming out the other side. I

jumpered the pot (i.e. simulate pot max volume) and my ears were

hurting. Upon removal of the pot I found a crack on the ALPS pc board

that has the leads mounted to it. Apparently, I must have hit the

volume control pot the previous day and cracked the pot trace (again

this trace was part of the pot not the rig pcb). I had noticed when I

disassembled the unit that there was no nut on the pot to hold it in

place (none on the squelch either). The volume pot is right at the edge

of the unit and is the most likely knob to get hit.

When parts arrived, it came with a nut so I installed it to help prevent

this problem in the future -- no problems since.

I think the switched volume pot cost $4.95 + $3.00 shipping.

I also picked up a set of backcase screws -- very small

heads but very long screws to replace my old ones -$.05 - Make sure you have a

"good" screwdriver that really fits.)

All these problems sound like the same thing. I have never had any problems

with my rig, and I bought one of the first ones out. (Hence, the software

update to give me the ability to lock out memory channels during scan.)

 

*********************************************************

Kenwood TH-215A / TH-215E Frequency Modification.

_____________________________________________

I'm not quite sure why we all do this, but here's how anyway.

In order to increase the frequency coverage of the Kenwood TH-215

Series Handheld Transceivers, a few jumpers inside the radio need to be cut.

No retuning is necessary. WARNING: The radio is compact internally; if

you do not have the delicate touch of a surgeon, forget this mod or get a

radio surgeon friend to do it for you.

Tools you will need : #1 Phillips Screwdriver

#2 Phillips Screwdriver

Diagonal Cutters (Very Small!)

Remove the Battery Pack, Antenna and Belt Clip.

Remove the 4 small screws in the recesses near the 4 corners

of the back of the radio. Do not separate the cases yet!

Place radio on a clean soft work surface Face-Up. With the

antenna connector facing away from you.

Lift the front case of radio STRAIT-UP. When clear of the rear

case, rotate the front case to the right and lay it on the

work surface Face-Down. Do Not Damage the Flat Cables.

KEEP YOUR FINGERS OFF THE ELECTRONICS!

Notice the 4 Copper colored jumpers on the surface of the circuit

board inside of the front case cover. These are located 1.5

inches "NorthWest" of the center of the speaker. They are

numbered J1 thru J4 from the bottom to the top. J3 is already

cut on the TH-215A.

Remove the jumpers as selected from the table below by cutting

through the thin area at the center of the jumper. BE CAREFUL!

Reassemble Radio. All memories will be clear and the display will

be at the lowest Transmittable Frequency (i.e. 141 or 144).

_____________________________________________________________________________

The Operating Frequencies are programmed by cutting jumpers as follows :

 

Jumpers. Transmit Freqs. Receive Freqs. Remarks.

No Cuts 144.0 - 145.995 144.0 - 145.995 TH-215E

J3 144.0 - 147.995 141.0 - 162.995 TH-215A

J3,J1 141.0 - 150.995 141.0 - 162.995

J3,J1,J4 141.0 - 162.995 141.0 - 162.995

Note: J2 has no apparent function, leave it IN.

 

*********************************************************************

KENWOOD TH-215A handheld transceiver out-of-band modification:

1. Remove two screws from belt clip

2. Remove 4 screws from back of radio

3. Slide front assembly off

4. Locate set of 4 jumpers:

(top front inside)

+--------------------------------------+

$ $

$ +--------+ $

$ $ $ $

$ $ $ $

$ +--------+ $

$ $

$ +--------+ $

$ $ $ $

J4: intact $ J4 o---o $ $ $

J3: cut $ J3 o) (o +--------+ $

J2: cut $ J2 o) (o $

J1: cut $ J1 o) (o $

$ $

$ SPKR $

$ $

$ mic $

$ mic $

$ $

+--------------------------------------+

5. Reassemble radio.

6. Reset microprocessor: Turn radio on while simultaneously pressing

both _F_ key and _ENTER_ key.

 

*********************************************************************

Subject: KENWOOD TH-215A TO TNC

THE HOOK-UP OF A TH-215A TO MY PAC-COMM TINY 2 TNC WAS VERY EASY.

THERE ARE NO COMPONENTS INVOLVED IN THE CONNECTION. ALL YOU NEED ARE

TWO PHONE PLUGS: 1 SUB MINI, AND 1 STEREO(3 CONDUCTOR) MINI.

BOTH AVAILABLE FROM RADIO SHACK,TWO TO A PACK.

IF YOU HAVE A KENWOOD SPEAKER MIKE, THEN THE INSTRUCTION SHEET WILL

CONTAIN A DRAWING SHOWING THE BASIC CONNECTING LINES. IF NOT, HERES

HOW ITS DONE:

THE SUB-MINI IS THE SPEAKER PLUG. THE CENTER PIN GOES TO THE SPEAKER PIN

ON THE 5 PIN DIN ON THE TNC, THE SHAFT IS THE GROUND.

ON THE MINI STEREO PLUG, YOU DONT USE THE CENTER PIN, JUST THE TWO

SHAFT CONNECTIONS. THE SHORT SHAFT GOES TO MIKE, THE LONG SHAFT IS THE

PUSH TO TALK......THATS IT, FOUR WIRES TO THE CONNECTOR THAT GOES TO

THE TNC PLUG, AND YOURE IN BUSINESS!!

ONE VERY VERY IMPORTANT THING-----ALWAYS MAKE SURE THAT ALL BATTERY

SAVE FUNCTIONS ON THE HANDY TALKIE ARE OFF. IF IT ISNT, A SLIGHT DELAY

IN RECEIVING WILL CAUSE RETRYS FROM THE STATION SENDING TO YOU, AND

WILL DELAY PACKET RECEPTION AT YOUR END. PLEASE MAKE CAREFUL NOTE OF THIS.

ANY QUESTIONS, REPLY TO K2JOV, HARRY, AT N2ELC-4 BBS IN N.J......GOOD LUCK!!th215a.2 144 - 165 TX/RX MOD

TO OPEN YOUR TH-205,215,OR 225 ALL YOU HAVE TO DO IS TAKE OUT THE SCREWS

ON THE BACK, AND GENTLY OPEN UP THE FRONT OF THE UNIT...LOCATE THE OBVIOUS

4 JUMPER BRIDGES ON THE PC BOARD. THE BRIDGES ARE NUMBERED J-1, J-2, J-3,

AND J-4..JUMPER J-3 HAS ALREADY BEEN CUT...CAREFULLY SNIP JUMPERS J-1 AND

J-2 AND EVER SO SLIGHTLY SEPERATE THE SNIPPED BRIDGES TO INSURE NO-CONTACT

BETWEN THE POINTS.. REASSEMBLE THE UNIT..LOOK AT YOUR INSTRUCTION MANUAL

AND RESET THE MICROPROCESSOR..THE MOD WILL NOT WORK UNTIL YOU RESET THE MPU...

THE INFO. FOR RESET IS NEAR THE BACK OF THE MANUAL..AFTER THAT THE UNIT IS

WIDE OPEN TO OPERATE BETWEEN 144 TO 165.



 

From : PB0AFK

To : MODS@WW

Type/status : B$

Date/time : 20-Dec 12:24

BID (MID) : 21769-PB0AFK

Message # : 322126

Title : KENWOOD TH22AT

Path: !I6BNW!IK6PYS!IK6RUY!IW0QMN!WB0TAX!N5VDA!LX0IST!SR9DIP!SR6DOP!SP6KBL!

!OK0PHL!OK0PPL!OK0PKL!DB0MAK!DB0ERF!DB0HSK!PI8DRS!PI8ZWL!PI8APD!PI8GCB!

!PI8WFL!PI8MBQ!PI8VNW!

 

 

 

From: PB0AFK@PI8VNW.#ZH2.NLD.EU

To : MODS@WW

* TstHost for Dos v1.43b - registered to PB0AFK *

* UTC diff: -1, Local time: 18-12-1998 00:35:46 *

* The world according to Garp and PB0AFK(Henk) *

* Msg:41773 Bid:21769-PB0AFK

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĶToplogo creator (c) 1997-1998 by PD0OLNºÄÄÄÄÄÄ

SUBJECT: KENWOOD TH22AT extended frequency operation.

This procedure will expand the capabilities from 136.000 to 173.995 MHz.

PROCEDURE:

1. Turn off power and remove battery pack.

2. Remove antenna and two knobs from top r 322104

of unit.

3. Gently pry the rubber escutcheon off the top of the unit.

 

4. Remove the two long screws from the rear of the radio case.

5. Squeeze the bottom of the front panel together and gently separate

the two case halves. Use caution so ar 322125

s to not damage the thin

ribbon cable connecting the front panel to the main unit.

6. Remove diode D208 located on the circuit board behind the front

panel.

7. Place the diode just removed in the location shown for diode D212

and solder in place. Observe proper polarity. The diode should

face the same direction as diodes D210 and D211.

8. Reverse steps 1-5 to reassemble.

9. Reset the microprocessor.

CAUTION: This modification requires soldering equipment rated for CMOS

type circuits. It also requires familiarity with surface mount soldering

techniques. If you do not have the proper equipment or knowledge do not

attempt this modification yourself. Seek qualified assistance.

PHYSICALr 322098

LOCATIONS

 

! ======== W201

!

TOP ! ======== W202

!

! __________________

! ! ! [D206] [D210]

----------------------- !

! ! [D207] [D211]

! CN203 !

! ! [D208] (D212)

thin ribbon ! !

! ! (D213)

! !

------------------------ !

! ! !

! ------------------ ___________

! __________! !

!_______________________________!__SPKR___!___MIC____!________

 

X57-4370-11 (B/4)

==========================================================================

73 de Henk

Pc 486dlc 5MB Svga 210MB Hdd Svga Cdr-player Tnc AEA Pk-88

Hp 100Lx PortFolio Psion user / TelephoneCard Collector /Jimi Hendrix devotee

 

'I use NO invisible TAG-line. Do NOT send me 10dollars for a invisible one'

Created by Mes_filter v1.06c

 

 

 

 

 

 

 

--- End of messsage #322126 to MODS from PB0AFK ---

 

KENWOOD TH-series HT TNC Interconnection

The following is a suggested circuit for connecting a packet TNC

to a Kenwood TH-series HT. Included is the TH-21/31/41, the TH-

205/215/315/415, and the new TH-25/45 series HTs.

The connections are as follows:

A sub-miniature plug is used for receive audio. The tip of

this plug is audio out; the sleeve of this plug is the

common ground for PTT, transmit audio, and receive audio.

A miniature stereo plug is used for transmit audio and PTT.

Connect the middle "ring" of the plug to the TNC audio out

through a 0.2 uf cap (for DC isolation). Connect the sleeve

of the plug to the TNC PTT. The plug's tip is unused.

Set the TNC audio for 50 to 80 mv audio output into a 2K ohm

impedance.



 

TH205 144 - 165 TX/RX MOD

TO OPEN YOUR TH-205,215,OR 225 ALL YOU HAVE TO DO IS TAKE OUT THE SCREWS

ON THE BACK, AND GENTLY OPEN UP THE FRONT OF THE UNIT...LOCATE THE OBVIOUS

4 JUMPER BRIDGES ON THE PC BOARD. THE BRIDGES ARE NUMBERED J-1, J-2, J-3,

AND J-4..JUMPER J-3 HAS ALREADY BEEN CUT...CAREFULLY SNIP JUMPERS J-1 AND

J-2 AND EVER SO SLIGHTLY SEPERATE THE SNIPPED BRIDGES TO INSURE NO-CONTACT

BETWEN THE POINTS.. REASSEMBLE THE UNIT..LOOK AT YOUR INSTRUCTION MANUAL

AND RESET THE MICROPROCESSOR..THE MOD WILL NOT WORK UNTIL YOU RESET THE MPU...

THE INFO. FOR RESET IS NEAR THE BACK OF THE MANUAL..AFTER THAT THE UNIT IS

WIDE OPEN TO OPERATE BETWEEN 144 TO 165.



 

From : CT1FMS

To : MODS@WW

Type/status : B$

Date/time : 04-Jan 12:57

BID (MID) : 59707_CT1FMS

Message # : 324913

Title : MODS --> KENWOOD TH78A -1-

Path: !VK7AX!HB9GL!SV1AAW!WB0TAX!KP4IG!EA1RCF!EA8AOP!EA8DW!CT1XK!CT1FOT!

!CT1FMS!

 

From: [email protected]

To : MODS@WW

Subject: Re: Kenwood TH-78 mods / Game

To "open up" as many feature as possible on the TH78A, remove diodes D4 & D5

(located under the copper shield).

This allows the following transmit and receive frequencies

RECEIVE TRANSMIT

--------------- ---------------

VHF BAND

--------

50-135.995 (AM) (NA)

136-179.995 136-179.995

300-399 (AM & FM) (NA)

SUB-UHF

400-511.99 400-511.99

UHF BAND

--------

400-511.99 400-511.99

900-949.9875 (NA)

SUB-VHF

50-179.995 (FM) 136-179.995

 

PERSONAL NOTES:

I found that marine weather reports at 162.40MHz in my area were received much

better on the VHF-SUB band, than on the VHF band. Possible hole?

If you are having problems with intermod, try switching BANDS (ie. USING the

SUB-VHF rather than the VHF etc.)

Cellular Phones are in the 870-890 range, but the frequency increments are

every 30kHz. The TH78A will only increment in 25kHz steps at this frequency

range, so the exact Cellular channel frequency cannot be tuned in (most of the

time).

 

 

 

Removing D4 enables the CROSS-BAND REPEATER function.

CROSS-BAND REPEATER

-------------------

Press [F] key for 1 second, then the [0] (zero) key to turn this function on

and off (MHz dot will flash when in repeater mode).

ANSWERBACK FUNCTION (during paging reception)

---------------------------------------------

Hold down [MHz] key and switch power ON to turn this function ON or OFF.

300 MHz AM/FM SWITCHING

-----------------------

Hold down [VFO] key and switch the power ON to switch between AM and FM

reception.

VHF & UHF EXPANSION

-------------------

Press and hold the [F] key for 1 second, then press the [BAND] key in the

respective bands.

CHANNEL DISPLAY MODE

--------------------

Hold down [3] key and switch the power ON. Channels are displayed by number

instead of frequency. (NOTE: this function only works when Alpha-Numeric

memory is enabled)

CLONE FUNCTION

--------------

Hold down the [0] and switch the power ON.

 

 

*** GAME *** (Available without any modifications)

--------------------------------------------------

Hold down the [M] and [PTT] keys and switch the power ON.

(Be very careful the PTT is depressed or else a memory reset will occur.)

1) Play the memory game.

The radio will beep and display one of the following characters: "1, 2, 3, F"

(top row of buttons). Radio starts with one character and adds a new one on

after every round until 20 characters are reached. You must press the keys in

the same sequence they are displayed. When you can follow the radio for 20

characters, then you will win 100 coins and enter the poker game.

(Note: I am terrible at this game, so I cheated by writing down the character

sequence on paper.)

2) Poker game. (Much more interesting than the first game, IMHO)

Place the bet (1 to 10).

Increase the bet with the up key [2], decrease the bet with the down key [5].

Press [F] to deal the cards.

Cards are (2,3,4,5,6,7,8,9,+,J,K,Q,A NOTE: 10 = "+")

Press [PTT] to see the suits.

Press numbers 1 through 5 to change the respective cards.

Press [F] to deal the new cards.

If you win any amount, you can bet for double or nothing.

Press [F] to play "BIG or SMALL".

Press [LOW] to keep your winnings.

BIG or SMALL

------------

A random card will be chosen.

Push [2] (big) if you think this card is going to be larger than 8.

Push [5] (small) if you think this card is going to be less and 8.

(if an 8 is drawn, then a tie occurs, and you neither win nor lose)

Press [F] to draw the random card.

You either double your winnings or lost it all.

Press [F] to continue playing Big or Small.

Press [LOW] to keep winnings and continue playing poker.

Push the [LAMP] key to exit the game mode.

Note: While in game mode, receive functions still operate!

----------------------------------------------------------

 

 

Best 73. Paulo, [email protected]

 

 

 

--- End of messsage #324913 to MODS from CT1FMS ---

(1) TA2EM BBS (H for help) >

From : CT1FMS

To : MODS@WW

Type/status : B$

Date/time : 04-Jan 12:57

BID (MID) : 59708_CT1FMS

Message # : 324908

Title : MODS --> KENWOOD TH78A -2-

Path: !VK7AX!VE1SMU!N5VDA!N9DBX!N7NEI!KL7IFW!N4ZKF!KP4IG!EA1RCF!EA8AOP!EA8DW!

!CT1XK!CT1FOT!CT1FMS!

 

 

 

 

From: [email protected]

To : MODS@WW

Subject: TH78A mod file, crossband repeat, extended RX/TX, cloning

"TH-78A Modification File"

 

Subject: TH-78A Modification File

Owner assumes all responsibility for modifying or using these

modifications!.

The following mods will provide for Crossband Repeat and extended

receive and transmit on the Kenwood TH-78A HT.

I believe other functions are also enabled by these mods. which I

have not found yet but I will update the file as news progresses.

Diode #4- Crossband Repeat

Diode #5- Extended Receive and out of band Transmit.

Remove all screws and open radio as explained in the Kenwood manual

for installing the memory expansion module.

On the back cover you will find the memory expansion module socket

and a copper shield to the upper left corner of it.

Under this shield their will be a row of SMC diodes which are

unmarked in a vertical configuration to the lower right portion

covered by the shield.

#1 Remove the shield at its four corners with a solder sucker and

SMALL! iron.

#2 Carefully count down from the 1st diode in the row to the fourth

one and remove for crossband repeat.

HINT: I found if you BRIEFLY touch the iron to the right side lead

while gently pulling up on the SMC diode it should completely come

off without needing to apply heat to the other side and further

risk board damage.

I used a pair of right angle surgical tweezers for this.

#3 Just as above you may remove the fifth diode to preform the

extended receive and transmit modification.

#4 Reset the CPU (yes you will loose all of your programed

memories! argh!) by pressing Function for more than one second and

then "0".

YOU HAVE NOW COMPLETED THE MODIFICATIONS!

#5 For 800Mhz go to the UHF band with the band switch and press

Function for more than one second quickly following with a press of

the Band switch again. 8---.-- will appear.

#6 For 300MHz go to the VHF band and repeat as above. Original

bands are restored by repeating the "F Band" sequence.

MY observations... All original functions have maintained the

same which is great. Aircraft band which was accessible before the

mod remains with the same characteristics. It seems that VHF-High

band has improved a bit on sensivity where it was dead as a dog

before the mod (above 155.000MHz) but the 162.000 MHz band where

weather radio is is still a bit deaf for reception at any distance

but about 20 Miles. This depends on your (or my) terrain and

transmitter output power.

On UHF all public safety frequencies up to about 500 MHz seem to

come in well but sensivity greatly drops from there (we really

can't ask for more). Frequencies can be programed in up to the

920MHz ham band but I have no way of measuring sensivity. 800MHz

works but the signals are very weak, you must be near the

transmitter for reception. Assuming you are in the town or city

where the transmissions originate it should work.

Transmit is enabled up to and incl. 500MHz but after testing this

on a frequency counter I find that a signal is only generated to

about 490 MHz, even though the trans. LED shows output in the

higher frequencies.

Crossband repeat seems to work fine but the audio is unacceptable

for use, BE AWARE the radio gets HOT! Prolonged use or use on a

busy frequency would not be recommended. Also remember this is a

dual band HT please use a proper antenna while in this mode to

avoid a high SWR, we should all know better... Right?

After first booting up the CPU in the mod I found that the message

screen showed "Cloning" so it seems that this radio now has cloning

capabilities. After searching I have found that holding the "0" key

and powering up the radio will display the clone feature, see below

for further explination.This leads me to believe that this HT may

have some more "Hidden" features that I am trying to find, some may

be useful.

Thanks to Gary KC8UD who sent me the following via packet .....

CLONING:

The TH-78 can be cloned without cloning cables or special equipment. It is done

entirely with RF, and, in fact, can be transmitted over the air, and even via

repeaters. This may be extremely useful for those users who do not have

the patience to program their own radios themselves. This application would

also be useful for clubs and user groups. (However, this can take as long as

50 minutes with the ME-1 expansion module. It is recommended that a dummy

load be used to prevent unwanted QRM.)

(1) Both radios must be on the same frequency.

(2) Activate both radios by pressing the "0" key while turning the power on.

The radios will display CLONE.

(3) Now, click the PTT of the "master" radio. The radio will transmit in the

conomy low power mode. This may take about 4 minutes for fifty channels.

hen the data has been transferred, both radios will revert back to the

riginal frequency.

(4) Turn both radios off and then on again. They will now operate normaly

while the slave radio has the same memory contents as the master radio.

FREQUENCY EXPANSION

(1) You can receive from 340 - 399.987 Mhz FM by removing chip diode D8 on the

ontrol unit. To access this function, press the [F] key for one second, and then

the [LOW] key. This toggles between AMATEUR, AIR band (AM) and 360 Mhz.

AM and FM modes are selected automatically, depending on frequency.

** Since "F" for a second and "Low" toggles the power output, I wonder **

There is also a couple of arcade type games on the TH-78A. To start the

game you pres and hold [PTT] and [M] keys while turning the unit on. The first

game is a follow me type game. The radio beeps and shows a sequence of

numbers flashing on the screen. You have to match the same sequence on the

tone pad. Each time the sequence gets longer by one number. You have to

keep remembering the sequence as one gets added each time. Once you get to

a certain high score on that game, it breaks into a poker type game. To exit

the game mode press the LAMP key at any time. The receiver still works in

the game mode and you can adjust volume but no other features.

RG> The games seem to work fine and it is interesting that they have

inserted that into the programing of the chips. Does anyone know of any further

features in the radio be it games or radio functions.

=============================================================================

Note: I haven't tried or verified this, proceed at your own risk. And

do not transmit outside of legal bands!

 

 

Best 73. Paulo, [email protected]

 

 

 

 

 

 

 

--- End of messsage #324908 to MODS from CT1FMS ---

 

KENWOOD R5000

Kenwood R5000 Modification Notes

The following describes some option jumpers and other features I have

found in the Kenwood R-5000 receiver.

The R5000 is fairly delicate internally, so you should not undertake

these modifications if you are not fairly confident of your ability to

work with delicate electronics (or to repair it if necessary). In

particular, the receiver's numerous circuit boards are connected

together with wire harnesses made of relatively fine and delicate

wires. Also, some of the boards (particularly the IF board) have small

"daughter boards" containing small surface mount parts vertically

attached to the main board. These are also fairly fragile, and caution

is required in handling them.

 

EXPANSION FEATURES

The R5000 has six "Expansion Feature" options which are not documented

in the user manuals. These are controlled by jumpers (actually diodes)

on the CPU board, which is attached to the back of the receiver's front

control panel, underneath a metal RF shield. Unfortunately, you must

completely remove the receiver's covers, and unfasten the front panel,

in order to access these.

Gaining Access to the Jumpers

To access the jumpers, remove the top and bottom covers of the receiver

by removing the eight silver screws which hold each cover in place. Use

caution at this point, since the radio will be sitting only on its

internal chassis, and delicate parts will be exposed.

Next, remove the four flat silver screws which were *under* the covers

(NOT the black screws that are visible with the covers on) which hold

the front panel onto the main chassis. Be sure the receiver is sitting

on a solid table so that the front panel will not fall off when you do

this, since there are a large number of wire harnesses connecting to the

CPU board. Very carefully pull the front panel forward and rotate it so

that you can get access to the back of the front panel.

Loosen the five small metal screws (two at the top, three at the bottom)

which hold the RF shield in place over the CPU board. The holes in the

shield the screws go into are slots, which allow you to slide the shield

off without removing the screws completely. This is fortunate since the

screws are fairly small. Remove the RF shield.

 

One other thing to note involves installing the optional filters.

First, I found that the AM filter which came with the radio introduced a

whistle into most AM signals. I replaced it with the optional AM

filter, and it eliminated the whistle (and gave a "fuller" sound to the

AM).

Also, note that if you install other filters, you have to install them

"in order" -- in other words, the narrowest has to go in the N position,

the next narrowest in the M1 position. Note that the M2 position is

already occupied (as shipped) by a high-quality SSB filter. The reason

they have to be in order is that as you select narrower and narrower

filters, the wider filters remain in the circuit, so if you put a

narrower filter in M1 than you have in N, it will stay enabled even when

you select the wider filter, causing the wider filter to have no effect.

It's a little unfortunate that it works that way, since the M1 filter is

only enabled by the switch (not in AUTO mode), which would be ideal for

the very-narrow YK88CN filter.



 

KENWOOD MC-85 MOD INFO

MOD FOR MC-85 MIC AND RC-1A PHONE PATCH

I am a Ham Radio Operator (call signed 4Z4MJ). My station is

exclusively Kenwood (TS-940s, TL-922, TR-2400, TR-7950, MC-

85, and the PC-1A phone patch) and I'm very content of having

the honor to belong to the Kenwood family.

In Israel, I work as an electronic design engineer and on my

free time, I'm always anxious to solve design problems and

add my own modifications to the shack. I would like to

present you the modifications I have made and hope they might

be helpful. (The mods deal with the MC-85 microphone and the

PC-1A phone patch; I enclose them with this letter and

emphasize the changes with the yellow marker, So let's

start........

When I purchased my TS-940S with the MC-85 microphone, I was

very happy with the 940 but sad about the 85. The problem

was R.F. feedback when I was touching the microphone's goose-

neck with my hand, (or when the linear was on, it happened

without even having to touch the mic).

Not only that, I was

not able to function the S-201 (mic selector of the MC-85) if

I was connecting more than one rig to the MC-85. At first I

thought my MC-85 is malfunctioning, but from talking with

five other hams in Israel who own the MC-85, I heard that

they all suffer the same problems!!

The main problem was caused because of a ground loop. There

were two (2) grounds to ECM unit (you know it's illegal).

The ground on the p.c. near the Q1 transistor is absolutely

fine, but what about the one that makes a ground connection

between the ECM unit and the top of the goose neck? The

solution is described on the enclosed paper marked (1). The

addition of (2) and (3) were needed to give more R.F.

attenuation to the common mode and to the differential mode

rejection respectively.

In summary, (2) and (3) are

necessary but (1) is a MUST. These mods cured completely all

the RF feedback problems that one can have with the MC-85.

Before closing the microphone's base cover, I added a few

more mods. I hope they are clear from the modified scheme

and the notes. (Notice that all these mods can be done

without having to remove the printed circuit board.) A

similar thing happened wtih the PC1-A phone patch...started

because of a "serious" problem and ended with extra "very

helpful" mods.

The "serious" problem was that no matter how loud I put the

RX gain control, there was never enough audio to the

telephone line, and not only that, the audio was distorted!

(See IRI of April, 1987, Issue No. 64, Page K64, where C.M.

Luchessa WN6O, suffers a similar problem and asks: "Any

remedial information will be appreciated".) The problem was

solved by changing D5 and D6 (originally they were clipping

the audio at 0.7 volts). I made the change by putting 3

silicon diodes on each leg, so now the clipping is done above

2 volts, and not at 0.7 volts, R11 was changed from 27 to 10

ohms. Again, before closing the patch's cover, I added a few

more mods.

A. I couldn't work vox properly with the PC-1A because

I couldn't null deep enough the bridge. VR1 was partly

nulling at the far end of it's position. Adding a 1.5k ohm

in parallel with R5 (or alternatively just changing R5 to a

single 470 ohm resistor) brought the null to the mid-position

of VR-1.

B. Although the null is now centered, it was not deep

enough. Adding on 0.1 uf disk capacitor in parallel with RF

balanced the reactive component of the bridge, the null

became extremely sharp!

C. An addition of a high pass filter to the patch that

gives the same effect as the "low cut" position on the MC-85

microphone was "very helpful" when the PC-1A was connected to

the SSB HF ring. The filter is simply made of a 10K ohm

resistor and an 0.02 uf capacitor. (see it on the modified

scheme (next month)).

With all the changes I made to both the PC-1A and the MC-85,

I'm most satisfied and I would very much like to hear your

remarks (maybe published in the I.R.I. too!).



 

Kenwood Mods.(1/2) Juli 1994

Erweiterungen an Kenwoodgeraeten

====================================

Hallo Kenwooduser !

Immer wieder lese ich Anfragen zu Erweiterungen verschiedener Kenwoodgeraete.

Um nun die Sucharbeit durch verschiedene Rubriken und/oder Boxen zu verein-

fachen, habe ich alle mir zu aktuellen Geraeten bekannten Aenderungen

zusammengestellt ( hauptsaechlich Frequenzerweiterungen ).

Ich liste sie in kuerzester Form stichwortartig auf.

Dazu moechte ich noch bemerken, dass die meisten Info's von Meldungen

anderer OM aus der Rubrik Kenwood der DB0HB-Box stammen, ich also nicht

alle Aenderungen selbst probiert habe und deshalb keine Garantie fuer ein

Funktionieren uebernehmen kann.

Uebrigens Garantie: Die Kenwood-Garantie e n t f a e l l t bei selbst

modifizierten Geraeten !!

Natuerlich sei noch darauf hingewiesen, dass die gesetzlichen Bestimmungen

zu beachten sind !

Fuer Korrekturen, Erfahrungsberichte und weitere Info's ueber Erweiterungen

bedanke ich mich im Voraus.

----------------------------------------------------------------------------

 

R 2000 :

-------

D 58 auf SW-Unit (hinter Frontplatte) raus

( RX bis 30 MHz)

R 5000 :

-------

D 73-76 auf Counter-Unit raus

( RX bis 30 MHz)

Suchlauf traeger- oder zeitgesteuert:

auf IF - Unit bei Steckverbindung 10 (3 Pins) Kabel zu Pin 3 trennen

und ueber Schalter legen

TH 22-42 :

--------

gruenes Kabel ( W 202 ) trennen - Achtung: NICHT W 201 !

TH 25 :

------

Auf Control - Unit ( X 53-3080-02 ) R19 - 21 raus,

Reset ( = clearing all memories )

Erfolg : 141 - 162,995 MHz

TH 26 :

------

JP 1 - Draht (links neben dem Akku-Pack) trennen

dann: 136 - 174 MHz

TH 27 :

------

Gruenen Draht unter Frontplatte trennen

Reset (" M " bei Einschalten druecken )

Frequenz etwa wie TH26

TH 28/48 :

---------

Diode D 10 auf Control - Unit entfernen

(sitzt halb rechts ueber CPU)

Erfolg : TH28 : 136 - 174,250 MHz FM

TH48 : 400 - 470 MHz FM

Bei TH28 : D 8 raus : 340 - 400 MHz

Bei TH48 : D 8 raus : 340 - 400 und 800 - 950 MHz

Bandwechsel : "F" 1 sec druecken, dann "LOW"

Cross Band Repeater :

Diode D 4 raus, dann "F" 1 sec druecken, dann "0"

TH 75 :

-------

gruene Drahtbruecke (hinter Tastatur) trennen; Reset machen

TH 77 :

-------

W 5 = gruene Drahtbruecke unter HD 404608 H (auf Seite mit Lithium-

batterie) trennen

( 136-174,400-512 MHz)

TH 78 :

------

RX:

PTT+ VFO druecken, dann Power on

Erfolg:

108 - 136 AM ; 136 - 174 ,320-390,405-485 FM in VHF;

in UHF: 410-510, 800-950 MHz

TX :

D 6 auf Control - Unit raus

Cross-Band-Repeater :

D 4 raus, dann fuer 1 sec. F druecken, dann 0 druecken

Clonen :

PTT und VFO beim Einschalten festhalten,

beim naechsten Einschalten 0 ( L.OUT ) festhalten:

im unteren Display steht CLONE, zum Senden PTT druecken

beim empfangenden Geraet genauso vorgehen ( bis CLONE - Anzeige )

dann beim sendenden Geraet PTT druecken, nach einigen Minuten

erscheint auf beiden Geraeten END

TH 79 :

------

gruene Drahtbruecke unter schwarzem Deckel ( fuer CTCSS-Unit) trennen

Erfolg:

67 - 179 MHz ( Menue Nr. 13 )

400 - 511 MHz ( Menue Nr. 14 )

300 - 399 MHz ( Menue Nr. 20 )

800 - 999 MHz ( Menue Nr. 21 )

TH 215 :

------

Unter Frontabdeckung halb links ueber Lautsprecher liegen 4 Bruecken :

J 4

J 3

J 2

J 1 , J 1,3,und 4 trennen

Reset : "F" und "ENTER" bei Einschalten druecken

Erfolg : 141 - 162,995 MHz

TL 922 :

-------

auf WARC-Baendern fahren:

fuer 18 MHz: auf 21 MHz schalten

Plate ca. 14 MHz abstimmen

fuer 24 MHz: auf 28 MHz schalten

Plate ca. 21 MHz abstimmen

TM 211 :

------

Auf Control - Unit (X53 - 3040 - XX) hinter Frontplatte neben

Kanalschalter liegen R 22, R 23, R 24, R 25

nach sich w i d e r s p r e c h e n d e n Informationen soll :

a) R 25 raus : RXund TX : 142 - 151,995 MHz

b) R 25 auf den Platz von R 24 setzen :

RX und TX : 138 - 154 MHz

c) R 23 und R 24 raus , R 22 und R 25 rein : RX 138 - 174 MHz

was wie stimmt, weiss ich nicht - macht was drauss !

TM 221 :

------

R 22 und 24 rein ; R 23 und 25 raus

( hinter Display )

RX und TX dann : 138 - 174 MHz

 

TM 231 : 118 - 174 MHz

-------

TM 431 : 340 - 470, 850 - 950 MHz

-------

TM 531 : 850 - 950 MHz, 1212 - 1320 MHz

-------

fuer alle drei Geraete:

Draht, der aus Display ins Innere haengt (in Ecke ueber IC 9 )

trennen

TM 241 :

------

Gruenes Kabel auf Control - Unit trennen und abisolieren

Reset ( " MR " bei Einschalten druecken )

TM 701 :

-------

Gruenes Kabel links unter Frontplatte trennen und abisolieren

Reset ( " MR " bei Einschalten druecken )

Erfolg : 142 - 151,995 MHz

TM 702 :

-------

Halbschale mit Speaker abnehmen; gruenes Kabel,das in Schleife aus

Front kommt und wieder reingeht, trennen

bei Wiedereinschalten erfolgt Reset = Memories weg; rig gibt

" congratulations" in CW; jetzt 136 - 174, 340 - 512 MHz

TM 721 :

-------

Unteren Gehaeusedeckel abnehmen

R 57 ( = schwarze Bruecke im Ausschnitt des metallenen Frontrahmens )

rausnehmen

Erfolg : 138 - 174 MHz

TM 731 :

-------

Widerstaende R25 und R 124 raus

Widerstaende R 123 und R 125 rein ( sind wahrscheinlich bestueckt !)

( R 123 bis 125 auf Control - Unit, links neben Lithiumbatterie,

R 25 auf Control - Unit, Unterseite ) ; RESET! (= MR+Power on)

Erfolg: RX/TX 136 - 174, 400 - 500 MHz

 

TM 732 :

-------

im Bedienteil 0-Ohm-Widerstaende (SMD-Bruecken,blau)

19 und 22 ausloeten

( es liegen 4 Stueck in einer Reihe;der ganz linke und der ganz

rechte sollten es sein )

Erfolg: 118 - 174, 410 - 470 MHz

118 - 136 : AM ohne TX

136 - 174 : FM auch TX

410 - 470 : FM RX und TX

Wenn nur RX - Erweiterung gewuenscht: auch R 21 raus

auf 64 Speicher erweitern:

Nach Anleitung im Manual Split-Kanaele auf "0" setzen

Ergebnis: 64 Normal-Kanaele

diese lassen sich aber auch mit =,- und + speichern !

auf 800 - 1000 MHz erweitern:

mit BANDSELECT UHF einschalten ; RX in VFO - Betrieb schalten,

dann MHz-Taste laenger als zwei Sekunden druecken

Ergebnis: eine QRGzwischen 800 und 1000 MHZ wird angezeigt

( wahrscheinlich nur RX , und funktioniert nur bei erweiterten

Geraeten , habe ich noch nicht probiert )

TM 733 :

-------

0 - Ohm - SMD - Widerstaende auf Rueckseite der Prozessorplatine

R 410 und R 414 entfernen

Erfolg:

118 - 174 MHz, ca. 350 - 470 MHz

( AM automatisch unter 136 MHz )

800 - 999 MHz, wenn MHz-Taste laenger als 1 sec gedrueckt

( auf 70 cm natuerlich )

 

 

TM 741 : ( einige Geraete sind schon ab Werk erweitert ! )

-------

fuer RX:

W 1 = gruenes Kabel vorn links bei abgenommenem Bedienteil trennen:

118 - 174, 410 - 470, 1100 - 1400 MHz

fuer TX:

im Bedienteil: Widerstand R 54 raus ( links neben Lithium-Batterie)

TX auf 2m: 136 - 174 MHz; RX 118 - 174 MHz, dabei 118 - 136 nur AM

800 - 1000 MHz :

70 cm-Band anwaehlen;VFO druecken, MHz-Taste laenger als 1 sec druecken

zurueck auf 70 cm : gleiche Prozedur

10 m : 18 - 54 MHz / AM auf 10 : F , SHIFT nacheinander druecken

zurueck in FM : wieder F, SHIFT

200 Speicher pro Band : MR, dann F + REV druecken

zurueck auf erste 100 : F + REV

TM 742 :

------

Unter der unteren Gehaeusehalbschale ( vordere Platine, rechter Rand )

sitzen acht 47 KOhm - Widerstaende auf einer Leiste.

Fuer jeden sind drei Loetpunkte vorhanden, so dass sie jeweils nach

oben oder nach unten ( O , U ) eingeloetet werden koennen.

nur RX auf : U U U O O U O O

RX + TX auf: U U U O O U O U ( Reset: MR + Power on )

Erfolg : 118 - 174 MHz ( 118 - 136 MHz AM ), dabei durch Halten der

MHz-Taste AM-FM umschaltbar

410 - 470 MHz

800 - 1000 MHz ( nur RX )

TM 941 A:

--------

gruene Drahtbruecke auf Hauptplatine trennen

( hinter Speakerbuchse fuer Speaker alle Baender )

TR 751 :

------

auf Control - Unit D 1 und D 12 raus

Erfolg: 140 - 160 MHz

D 16 raus : 1 Khz-Schritte in SSB und CW

TR 2600 :

-------

Dioden D 32 und D 33 raus

( untere rechte Ecke des PC - Boards = X 55-1380-10 A2 )

Frequenz : ca. 140 - 160 MHz

TR 9130:

-------

auf Control - Unit D 18 bestuecken

Lithiumbatterie rausnehmen

Geraet aus- und wieder einschalten

Betterie wieder rein

TS 50 :

------

TX durchschalten:

auf Platine unter Bodenplatte Diode D 5 nahe back-up-Betterie raus

TX - output regelbar :

ueber kleines weisses Plastikpoti in der Mitte der Platine unter der

oberen Gehaeusehalbschale rechts neben Lautsprecherhalter

10/1 Hz - Anzeige :

a) Menue ueber F.Lock anwaehlen

b) 2. Menueebene einschalten, Nr. 70 anwaehlen

c) mit UP/Down Nr. 85 der PF 4 ( Miketaste ) zuweisen

d) mit F.Lock aus Menue

Jetzt kann mit Miketaste 4 ( ganz rechts ) 10/1 Hz - Anzeige

eingeschaltet werden

Falls letzte Stelle nicht im 5 - Hz - Raster, Abstimmknopf schnell

hin und herdrehen ( evtl. mehrfach )

FM - Bandbreite auf 10 KHz :

Austausch des Keramikfilters der 3. ZF (CF1) auf TX/RX-Platine neben

Quarz F1 und ZF-Baustein IC2. CF1 = schwarzer Wuerfel, bezeichnet:

CFW455F.

Dieser wird getauscht gegen +/- 6 KHz Version CFW455HT.

Dabei muss Pin 1 mit einem Draht etwas verlaengert werden, um ihn

etwas versetzt und zu Pin 5 ausgerichtet einloeten zu koennen.

 

TS 140 :

-------

D 31 auf Control-Unit raus

TX: 1,6 - 32 MHz, RX bis 35 MHz

TS 430 :

------

D 39 und D 40 auf RF - Unit ( Platine 44 151 000 ) raus

( liegen bei Q 22, neben 2 - und 3 - poligem Stecker)

Erfolg : TX laeuft durch

TS 440 :

------

D 80 auf Control - Unit ( hinter Frontplatte ) raus

dann TX 1,6 - 30 MHz

D 66 raus : 10 - Hz Anzeige

FM-RX schmalbandiger:

auf RF - Platine ( Unterseite des Geraetes ) Leiterbahn zwischen

R 59 und C 131 trennen,

eine Diode ( z.B.: 1N4148) mit Anode an R 59 und Kathode an C 131

loeten, zweite Diode 1N4148 mit Anode an R 58/C 130 und Kathode an

C 131 loeten, R 57 entfernen

jetzt wird das 8,83 MHz-Filter der 2. ZF auch bei FM benutzt !

 

TS 450 :

------

D 27 auf Digital - Unit raus (= TX durch )

( ACHTUNG : sitzt unbeschriftet auf der Rueckseite (!) der Platine,

es ist die obere Diode ! )

D 23 raus, dann RX 30 KHz - 40 MHz, aber 10m-Output dann nur 50 W ?

D 20,21,23 raus, D 22 rein : RX 30 KHz-40,5 MHz bei 100 W

TS 680 :

-------

In der Mitte der Platine unter dem unteren Gehaeusedeckel Diode

D 31 raus

Erfolg : TX + RX : 1,6 - 33 MHz

49 - 56 MHz ( mit 50 MHz Option )

TS 690 :

------

wie TS 450, wenn auch D 23 raus : RX 30 KHz - 60 MHz

TX 1,6 - 30 MHz + 49 - 54 MHz

TS 711 :

-------

D 30 auf Control - Unit raus: 144-154 MHz o d e r

D 34 auf Control - Unit raus: 141-151 MHz

Scanner wahlweise nf- oder zeitgesteuert:

D 28 auf Control - Unit ueber Schalter legen

( Platz fuer 1-mal-um Mini-Schalter auf Frontplatte zwischen

RF-Power und Shift-Reglern )

 

TS 790 :

-------

D 29 hinter Display raus

Reset ( A/B bei Einschalten druecken )

RX : 135 - 174 , 300 - 950 MHz

fuer TX : D 29 und D 30 raus

TX dann : 136 - 170 , 420 - 470 MHz

TS 811 :

-------

fuer Scannerumschaltung wie TS 711

Frequenzerweiterung nicht bekannt

TS 811 mit PR

-------------

wenn zu wenig NF an ACC 2 - Buchse, R 2 = 10 KOhm auf SW - Unit

( kleine Platine an ACC 2 - Buchse ) kurzschliessen

TS 850 :

-------

D 11 hinter Frontplatte auf freier Unit raus

( Platine vor Luefter,in der Mitte IC 18, darunter Diodenreihe)

D 11 kann auch auf Rueckseite der Platine sitzen !

Achtung white sticker !

Beim Einschalten VOICE gedrueckt halten

Erfolg : Jeder Knopf auf der Frontplatte bestaetigt Betaetigung

mit CW - Signal !

TS 940 :

------

Diode D 130 auf Digital-B2-Unit raus

( Unit liegt hochkant hinter LCD-Display;

Frontplatte runterklappen,auf Unit sitzen in Reihe 3 28pol. ICs,

zwischen mittlerem und rechtem, etwas oberhalb, sitzt D 130 )

Reset ( A=B beim Einschalten druecken )

Erfolg : RX 30 KHz - 30 MHz

TX 1,5 - 30 MHz

TS 950 :

-------

D 17 auf Digital - Unit raus

Reset ( beim Einschalten A=B druecken ) machen

--------------------------------------------------------------------------

Das ist alles, was ich bisher gesammelt habe.

Wenn Ihr nicht ganz sicher seid, lasst lieber die Finger davon.

Besonders bei der SMD - Technik geht leicht mal was daneben !

( Ich spreche aus Erfahrung , hi )

Und nicht vergessen:

Keine Kenwood - Garantie bei selbst modifizierten Geraeten !!!

Nicht alle Modifikationen habe ich selbst ausprobiert, kann also keine

Garantie fuer deren Richtigkeit uebernehmen.

Wer mehr Informationen zu einem der aufgefuehrten Geraete braucht, findet

diese in den Boxen unter der Rubrik Kenwood oder direkt von mir, soweit

vorhanden.

73 es 55 beim Basteln de Winni, DL3XU / DB0HB