Modifications for the Yaesu FT-470

19-07-1998 FT-470 Undocumented feature

The yeasu 470 2 meter/440 handie has a number of undocumented feature that can add to your enjoyment of this neat ht. Two modification can easily be performed from the keypad itself. This first allows the 470 to function as a 2 meter to 440 crossband repeater. The second allows you to increase the vhf receiver range.

Before you can put the 470 into repeater mode, you need to construct the following cable to p
                          8 OhmS

After constructing and installing this cable on the handie you need to put it into repeater mode. This is done by setting the 2 meter receiver transmit frequencies (the repeater does support transmitting an offset of the receiver frequency). second turn off the 470, hold down the rpt button on the keypad and turn the power backions!

73'S DE Karl N0IHY @ WB0GDB MSYS @ BBSIHY in bloomington

19-07-1998 Extended receive by the Up and Down Key

Increasing the receiver coverage of the ft-470 is also very easy to perform. Turn off the 470, while holding down the up down arrow on the keypad now turn the 470 back on. You have now increased your receiver coverage to 130-180 MHz.

73'S DE Karl N0IHY @ WB0GDB MSYS @ BBSIHY in bloomington

19-07-1998 FT 470 Unlimited (more or less) Rx mod

by N8ORO, relayed by N2KYW @ W2SEX.#WNY.NY.USA.NA

It's probably best to start with a clean slate, so reset your rig with the following RESET mod I recently saw on the bbs (I'm sorry but I didn't write down the contributor)

Put rig on 2m band
Turn rig off
Hold down MR, 2, VFO, and turn rig on
Let go, turn rig off
Turn rig on
Let go, then press DOWNARROW

Now for the actual mod. This mod is outlined for one band, but must be repeated on the other band (the following mod, not the RESET mod).
Remember, hardware will only support so much. Outside that all you will hear is transistor noise. (thus it's really not a tragedy that 1450 is the upper limit.) Another note of interest - after doing this mod you may observe a repeating pattern of stations as you traverse the spectrum, as if the band repeats, while the display continues to increment (Upon doing a similar, but hardware, mod to my FT 411, I noticed this condition with a cycle of 34.6 MHz. If you want this mod (411) please send me a note). This condition has been observed on the 411, but hasn't been verified on the 470. Keep an eye out just the same. You might also notice this mod is similar to many of the other mods for this rig sent lately - this is in fact a 'mod'ification of those mods. Thanks to the original contributor (again, I've lost track of who that was)
  1. Make UHF the primary band, VHF the secondary.

  2. Tune to 450 MHz.

  3. Press FM, RPTSET, and dial 0000 with the keypad.

  4. Turn rig off, then on again.

  5. Set the RPTSET to "+".

  6. Hit REV. Display should read 1450 MHz.

  7. Store this in the "U" memory.

  8. Hit REV.

  9. Tune to 430 MHz.

  10. Set RPTSET to "-".

  11. Hit REV.

  12. Tune down (and ONLY down) to 600 MHz.

  13. Press REV. Display should read 000.00 MHz.

  14. Store this in the "L" memory.

  15. Press UPARROW once to restore to 430 MHz.
To tune in any freq:

Press MR to bring up the U or L memory.
Put rig in MT (memory tune) mode by hitting MR again.
Use UPARROW or DOWNARROW to scan to freq, then store in mem.
The VFO's operate normally, and TX is still standard.
Have fun, and thanks again to N8ORO.

19-07-1998 YAESU FT-470 STRAPS

I Have located a total of eight straps, four to the left of the lithium battery, and four others located under the flat white cable that interconnects the upper half with the lower half.


R69 Vertical, at the 10 o'clock position by the lithium cell.
R68 Horizontal, to the lower left of R69.
R67 Horizontal, just below R68.
R66 Horizontal, just below R67.

R71 Vertical, the leftmost of three, to the left of the upper corner of the ribbon cable connector.
R70 Vertical, the center of three of which R71 is the leftmost.
R72 Vertical, the rightmost of the three.
R74 Vertical, to the left of the ribbon cable connector, below the three. (Note that R74 is below an unpopulated capacitor that does not have a C number.)

There is no R73, or at least it is not on the circuit board and it is not in the schematic. And, yes, the order of those three is indeed R71, R70, R72, left to right.

R70, R71, R72 select the mode for the UHF portion of the FT-470. The choices are :

                     UHF CHOICES
R71   R70   R72         Rx and Tx.          Receive only
 0     0     0          430 to 440 Mhz      430 to 500 Mhz
 0     0     1          430 to 450 Mhz
 0     1     0          430 to 440 Mhz
 0     1     1          432 to 438 Mhz
 1     0     0          430 to 440 Mhz
 1     0     1          220 to 225 Mhz
 1     1     0          430 to 440 Mhz
 1     1     1          210 to 235 Mhz

R66, R67, R68 and R69 select yhe mode for the VHF portion of the FT-470. The choices are :

                     VHF CHOICES
R66   R67   R68   R69   Rx and Tx          Receive only
 0     0     0     0     144 to  146 Mhz   130 to 180 Mhz
 0     0     0     1     144 to  146 Mhz
 0     0     1     0    1260 to 1300 Mhz
 0     0     1     1    1240 to 1300 Mhz
 0     1     0     0     140 to  150 Mhz   130 to 180 Mhz
 0     1     0     1     140 to  174 Mhz
 0     1     1     0     303 to  343 Mhz
 0     1     1     1     8AL to  242 Mhz
 1     0     0     0     144 to  148 Mhz
 1     0     0     1     144 to  146 Mhz
 1     0     1     0    1240 to 1300 Mhz
 1     0     1     1     404 to  444 Mhz
 1     1     0     0     140 to  160 Mhz
 1     1     0     1    1260 to 1300 Mhz
 1     1     1     0     101 to  141 Mhz
 1     1     1     1     1R3 to 158L Mhz

(Note: The receive only ranges are enabled by powering up the unit with the up and down arrow buttons depressed...)

When there is more the one combination which has the same frequency range, the difference is the default step size and/or the default repeater offset. Of course, choices that do not match the VCO and filters do not actually transmit or receive on those frequencies. A particularly strange example is that the VHF side of the set can be set to tune from 404 to 444 Mhz, but again, it won't actually lock. Even in the 101 to 141 mode, the VHF VCO will not lock - this mustbe for use with some other sort of VCO (It looks like this would cover the aeronautical band rather nicely.) There are two really wierd VHF settings, those for 8AL to 242 and 1R3 to 158L. These must be for use with some other LCD controller - it displays truly unusual and non seguential thins when stepped through the "bands".

R74 seems to have something to do with something like selecting the IF frequency, or something else like that. When set, it really srews up the VHF reception.

My technique for determining these straps is to remove the straps that come in the unit, solder wires to each pad, run the wires out of the unit to a bank of DIP switches, screw the unit back together, and the go trough all of the DIP switch combinations. I usually use a stereo microscope and 30 guage wire for this. Since I didn't try powering the unit on with every combination of keys held down for each DIP switch combination, there may still be other secrets possible.


The unit does a very good job as a cross-band repeater.

To enable this, turn off the radio, hold down the 'RPT' key and turn on the radio. Now, anything heard on EITHER band will be re-transmitted on the other band. There are, however, a few problems.

First, there is no real internal path for the audio to get from the receiver to the transmitter, so you either have to modify the radio, to provide a path, or do what I did which is to build a short loop back cable connecting the tip of the earphone jack to the tip of the microphone jack like this:

      Mick <-------------IIIII------------> Ear.


This is the way I did it, others have talked tohave used either just a resistor like me or a small capacitor, or a combination. On my radio, this value of resistor gave me a good range of transmitted audio levels by adjusting the volume control.

The other small problem is that the radio automatically selects low power on transmit in this mode. This is probably because of the lack of a real duplexer.

19-07-1998 Sensitive for the FT-470, from 130-180, to 430-500 MHz

Empfindlichkeit FT470

MHz µV
130 1
135 0,44
140 0,22
145 0,21
150 0,26
155 0,6
160 0,9
165 2,4
170 8,1
175 27
180 90

430 0,21
435 0,21
440 0,21
445 0,21
450 0,24
455 0,31
460 0,5
465 0,9
470 1,2
475 1,3
480 2,9
485 6,9
490 5
495 6,9
500 14

Signalgenerator (Marconi 2022) an Antennenbuchse. Am Lautsprecherausgang der Funke wird die NF-Spannung (FM-Rauschen) ohne Signal auf 100mV eingestellt. Dann wird das unmodulierte HF-Signal im Pegel soweit erhöht, bis das Rauschen um 20dB zurückgegangen ist.
Vorteil dieser Methode: Sie ist äußerst einfach durchzuführen.
Allerdings können mit dieser Methode die Propagandadaten der Prospekte nicht erreicht werden weil hier ohne Modulation und ohne CCITT-Filter gemessen wird. Zum Vergleich mit anderen Funken geht dies aber hervorragend und der Empfindlichkeitsverlauf über die Bandbreite läßt sich sehr schön darstellen wenn man die Meßwerte in z.B. Excel graphisch auswertet.

19-07-1998 YAESU FT470 cross-band repeater

If you turn on the radio with the RPT key depressed, the radio becomes a crossband repeater. Dial up two frequencies you want to crosslink (be sure to pay attention to transmit offsets, if any), turn the radio off. Depress the RPT key while turning it back on.
The tone encode/decode flags and the -+ flags will be flashing. When either band's squelch opens, the other band is moved into the primary frequency display and the transmitter keys.
Note that the power output is decreased to LOW power. I made up an audio interface, using a mini and sub-mini phone plug. Tie the grounds together, and connect the center pins through a 0,01 uF cap. and 47K resistor in series.
Adjust the volume control to about the 11 O'clock position. It work for both simplex cross-band and using a repeater on one band and a simplex freq on the other band. You do have to wait for the repeater to drop before you transmit on the simplex freq.

19-07-1998 Software RX frequency expansion

  1. Program 144.000 simplex into VHF vfo.

  2. Press Function key F/M and then press RPT key to obtain the repeater shift.

  3. Enter the code 0000 (four time zero).

  4. Turn the radio off and then back on.

  5. Press the RPT key twice to set + offset.

  6. Press REV key once. Now display is 1.144.000 MHZ.

  7. Enter this freq. into the U memory (Upper scanning limit) without the repeater offset.

  8. Now from 1.144.000 MHZ with + displayed in VFO, go to 1.100.000 MHZ. The fastest way is to push F/M key and DOWN key but if you pass 1.100.000 MHZ, you will need to restart from the beginning.

  9. Push REV key to obtain 100.000 MHZ on the display.

  10. Enter this into the L memory (Lower scanning limit) without the repeater offset.

  11. Enter a value of 200.000 MHZ in U memory.

  12. Now you can use the two limit memories L AND U as a third VFO able to scan from 100 to 200 MHZ (push F/M and MR when you are in L memory).

  13. For UHF repeat same process at UHF vfo starting from 430.000 MHZ to obtain a range of 400 to 500 MHZ.

  14. The sensitivity is lower than specifications outside the amateur band, but there are many transmitters you can stil monitor.

  15. After this modifications restore your repeaters offsets.

19-07-1998 ***TURBO SCAN*** 20 frequency in sec

The way to get it to turbo scan is easy. it's done all on the key board. here's how it goes:
  1. Bring up your main band and your sub band on screen

  2. Press fm then the alt key

  3. Press either the up or down button to scan in alt mode

  4. Open sql and look at your main frequency
    a) if it stopped on a uhf frequency close sql and try again until you get a vhf frequency on main band

  5. Now comes the easy part. while the sql is still open hit the vfo button

  6. Close the sql and hit either the up or down to scan again.
Bang!!! you got it at 20 frequencies per second.

***To get out of this mode***
  1. Hit either the up or down button to stop scan mode

  2. Hit the fm button

  3. Then hit the alt button right after and your back in regular mode.
You will not loose any memory with this mode

19-07-1998 VHF xmit and UHF recive

Here is a reposting of the mod to extend the receive range of the new Yaesu dual band handie to 130 - 180:
  1. Turn radio OFF.

  2. Hold down both UP and DOWN arrows.

  3. Turn radio back ON.
I will trade the mod for VHF xmit for one to open up UHF for recieve...I want to listen to UHF public service (450-470).

To enable VHF transmit:
  1. Open the radio such that the two halves open like a sandwich.

  2. Locate the internal lithium battery

  3. Locate several solder pads to the left of the lithium battery.

  4. Just to the top left of the lithium battery is ONE vertical solder pad. It is almost under the top left edge of the battery.

  5. solder a jumper accross this pad.

The other solder pads do several things, none of which seemed interesting to me: one set VHF band to 144-146, one replaces 2m band with 1260Mhz (would be nice if there was a 1260 Mhz RF module available...), two others seem to disable the squelches for the separate bands...etc. like I said, not too interesting.

Also note that for some reason the automatic repeater shift (- offset below 147, + above etc...) goes away when you enable VHF xmit using this mod. I guess you can't have your cake and eat it to. Oh well...

19-07-1998 1240-1300 TX & RX...and...220-225 MHz TX & RX

I have been reviewing the ft-470's capabilities for some time now, and was just wondering if anyone out there in rf land has done two neat mods that i have here! we all know that by removing r69 and jumppering it, you will be able to tx & rx from 140-174 mhz! well, further reviewing made me quite curious!

There are two more mods that you can do with only two (2) micro dip switches, which will give you: 1240-1300 tx & rx...and...220-225 mhz tx & rx! gee, that is two more ham bands, and with the aid of the dip switches, we have a total of 4 ham bands! this idea is not mine in it's entirety, it has been here for some time, but with only two dip switches it is a welcome treat indeed! for the vhf side of things:

Remember r69 that you removed and jumpered? well, if you remove r68 and and a dip, when you engage the switch it will give you 1240-1300 mhz tx & rx! you see, it actully takes two switches, one for r69 and one for r68. Well, r69 is already done so don't worry about it! and when you disengage it, it will perform as normaly as it did before!

UHF side of things:

If your rig already can tx from 430-450 mhz, you are half done! when this mode was performed, you removed and jumperedr72, right? now, all you have to do is remove and jumper r71, which will coexist with r72, and get 220-225 mhz tx & rx! gee, that was neat huh!?
Of course, you did use a dip switch for r71, right!?
I recieved the mods from my local bbs, and at the moment can not remember who gave all this neat info, but there is sure a lot of it! i figured that if you are boared of a certain band, You could change it! i have not done this yet, and am wondering if anyone out there has, and what type of sucess he/she had! what kind of tuning was necessary,(if any!) output power, you know, the rundown bit! well, hope this helps, and again, hats off to all those who contrib uted!

Info from [email protected] Jim Spragg

The mod floating around (for quite a while now) that tells how to get the FT-470 to tx & rx in the 220 & 1250 mhz bands does NOT work. I have this radio and tried the mods for the rig. The rig will convert to those bands, but only for looks. It niether tx or rx there. I contacted Yaesu directly and they confirmed this. Would ha been a nice touch! Oh well!

Jim Spragg KA8LGF

19-07-1998 Strappings for FT470-R

A2650 FT470 Strappings

TYPE    Freq.Range        preset freq.   Repeater shift
====    ===============   ============   ==============
 A1     144-148/430-450    144/430        0,6 /  5 Mhz
 A2     140-174/430-450    140/430        0,6 /  5 Mhz
 A3     140-174/430-450    140/430        0,6 /  5 Mhz  
 B1     144-146/430-440    144/430        0,6 /  7,6 Mhz
 B2     144-148/430-440    144/430        0,6 /  7,6 Mhz
 B3     140-174/430-440    140/430        0,6 /  7,6 Mhz
 C1     144-146/430-440    144/430        0,6 /  1,6 Mhz
 C2     144-148/430-440    144/430        0,6 /  1,6 Mhz
 C3     140-174/430-440    140/430        0,6 /  1,6 Mhz
 D      144-146/432-438    144/432        0,6 /  1,6 Mhz
 F      144-146/430-440    144/440        0   /  5 Mhz

TYPE    R66   R67  R69   R70   R71   R72
====    ===   ===  ===   ===   ===   ===
 A1      x                            x
 A2            x                      x     (TX= 140-150)
 A3            x    x                 x
 B1      x          x     x     x
 B2      x                x     x
 B3            x    x     x     x
 C1      x          x           x
 C2      x                            x
 C3            x    x           x
 D       x          x     x           x

 Control Unit jumper position   x = Available zero ohm resistor
                                  = open

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  !                               R 6 8               /            !
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  !                             R 6 7            6/                !
  !                                             /9                 !
  !                             R 6 6          /    battery        ! 
  !     R R R        ==                       .                    .!
  !     7 7 7        ==                                          / !
  !     1 0 2        ==                                        /   !
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            Onderkant print verder niet getekend.......

For packet : power save OFF!!!!
             C 3089 and C 3093   out!!!(squelch faster((4,7 uf))

19-07-1998 FT-470 fuer 9600 bps packet


ich habe mein FT470 fuer den Betrieb mit 9600Bd-PR "umgebaut" und moechte mein Vorgehen beschreiben. Vielleicht interessiert es ja den Einen oder Anderen FT470-Besitzer. Ich gehe bewusst ausfuehrlich vor, damit die Problemchen die ich hatte, nicht nochmal auftreten.

Zunaechst sollte man bedenken, dass der Bertrieb in 9600Bd mit einer Handfunke (aber auch mit diversen Mobilgeraeten) sicher nicht das Optimum darstellt. Wie schon mehrfach an anderer Stelle gesagt, ist die Modulation an einem VCO der an eine PLL angebunden ist, problematisch. Fuer eine optimale, retry-arme Uebertragung muss der gesamte NF-Bereich von einigen Hz bis knapp 10KHz ohne nennenswerten Frequenz- und Phasengang uebertragen werden koennen...

Wer also etwas Optimales fuer 9600Bd haben moechte, sollte von VCO-modulierten Geraeten (wie z.B. Handfunken) die Finger lassen.

Doch nun zur Praxis:

- Jegliche Ersatzansprueche bitte nicht an mich -

Das Geraet muss komplett zerlegt werden.
Wer so einen Geraeteeingriff vornimmt, sollte ueber einige Loeterfahrung und etwas Fingerspitzengefuehl verfuegen !
Ausserdem sollte man sich verschiedene, genau passende Kreuzschlitz- schraubendreher bereitlegen, um die z.T. festsitzenden Schrauben im Geraet sauber loesen zu koennen.

  1. Der Akku bzw. der DC-Adapter wird entfernt und die Geraeteknoepfe auf der Oberseite des FT470 werden abgezogen. Die Guertelklemme auf der Rueckseite wird abgeschraubt. Die beschriftete Deckplatte (Geraeteoberseite) wird abgeschraubt und die Gummidichtung wird ueber die Knopfachsen und die BNC-Buchse abgezogen.
  2. Das Geraet wird mit dem Display nach oben hingelegt und die beiden frontplattenseitigen Schrauben in der Akkubefestigungsplatte werden entfernt.
  3. Die drei von der Geraeterueckseite zugaenglichen Schrauben die die Gehaeuse- halbschalen zusammenhalten werden entfernt.
  4. Nun werden die auf den Knopfachsen sitzenden, mit jeweils zwei Schlitzen versehenen Befestigungsmuttern ein paar Umdrehungen gelockert. Ebenso die Befestigungsmutter der BNC-Buchse.
  5. Das Geraet liegt nun wieder -Frontplatte nach oben- vor dem Umbauer und die beiden Gehaeusehalbschalen werden wie ein Buch v o r s i c h t i g auseinander geklappt.
  6. Das Flachbandkabel wird von dem Platinenstecker geloest der sich auf der Platine befindet, die in der linken Gehaeusehalbschale (schwerere Haelfte mit Geraeterueckseite) sitzt. Nicht mit Gewalt ziehen, sondern erst die beiden Kunststoffklaemmerchen an den Seiten des Steckers in Richtung des herausgefuehrten Flachkabels loesen.
  7. Beide zu erstellenden Anschluesse, sind in der schweren Gehaeusehaelfte auszufuehren. Um moeglichst nahe an die Kapazitaetsdioden zu kommen, muss die Platine mit dem eben geloesten Platinenstecker entfernt werden. Diese ist mit einem weiteren Platinenstecker huckepack auf der unteren Platine aufgesteckt. (Schrauben waren hier keine zu loesen - glaub ich..) Man kann den Stecker sehen, wenn man den rechteckigen Gummistopfen in der rechten Seite der Halbschale entfernt. Das Abziehen des Platinensteckers wird erleichtert, wenn man das Oberteil des Steckers mit einem kleinen Schlizschraubendreher etwas anhebelt, bis sich die obere Platine loesen laesst.
  8. Die nun sichtbare Platine wird abgeschraubt. Dazu muessen nur die von oben sichtbaren Schrauben geloest werden, nicht die an den Seiten des Gehaeuses. Wenn die Schrauben geloest sind, kann die Platine senkrecht nach oben heraus- gehoben werden. Dabei sollte man die Warmeleitpaste an den PA-Modulen nicht allzusehr verschmieren. Die Platine wird nun mit der Loetpunktseite nach oben und mit der BNC-Buchse vom Bastler wegzeigend auf den Tisch gelegt.

    Die PLL-Einheit mit dem zu modulierenden VCO befindet sich in einem der beiden auf der Bestueckungsseite sitzenden Abschirmgehaeuse. Auf dem Aufdruck der Platine steht 144 PLL UNIT und 430 PLL UNIT letztere ist hier interessant. Man sucht sich die 430 PLL UNIT heraus und verfolgt nun wieder auf der Loetseite der Platine, die 11 Loetstifte dieses 430 PLL UNIT. Pin Nr. 1 liegt an Masse und an Pin Nr. 10 wird nun ein duenner Draht angeloetet. Vorsicht: Keinen Kurzschluss loeten ! Pin 10 ist der vorletzte Pin von rechts.

    Man sollte parallel zum Umbau den Schaltplan konsultieren.

    Der Draht sollte ca. 10cm lang und flexibel sein (Litze).

  9. Die Platine wird nun wieder in die Halbschale eingebaut und der Draht kann zwischen rechter Platinenkante und Gehaeusewand herausgefuehrt werden. Die BNC-Mutter kann wieder festgezogen werden. Die obere Platine wird nun wieder mit dem Platinenstecker aufgesteckt. Dabei sollte man N I C H T auf die Platine druecken, sondern mit einem Schrauben- zieher durch die Oeffnung in der der Gummistopfen in der Gehaeusewand war, auf den Stecker druecken.
    Nun koennen auch die Knopfmuttern wieder festgezogen werden.
  10. Nun kommt der Anschluss des Demodulators. Das Demodulator-IC befindet sich unter der Abschirmplatte die man nun auf der Platine sehen kann. Diese wird an einigen Punkten abgeloetet und leicht hochgebogen. Es geht um das IC mit der Nummer "10487" in der Aufschrift, welches unter der Abschirmung sitzt. Man nimmt einen ca. 10 cm langen Draht und loetet diesen an Pin 11 des ICs an. Pin 1 des IC ist da, wo der Punkt sitzt. Pin 11 ist der 11. Pin im Gegenuhr- zeigersinn.
    Die Abschirmung wird wieder angeloetet und der Draht so herausgefuehrt, dass die Isolierung nicht durch spitze Bauteilebeinchen durchstochen/durchscheuert werden kann.
  11. Die Herausfuehrung der beiden Signale aus dem Geraet bleibt der Phantasie des Verbastlers ueberlassen.
    Ich habe sie ueber 10KOhm-Widerstaende und eine 2-adrige, abgeschirmte Walkmannkopfhoererleitung durch den seitlichen Gummistopfen herausgefuehrt. Die Abschirmung der Leitung habe ich am naechstgelegenen Massepunkt der Platine angeloetet.
    Es geht aber sicher auch anders... 3-pol-Klinken-Stereobuchse o.{. ...
  12. Das Flachbandkabel wird nun wieder in dem zugehoerigen Platinenstecker befestigt und das Geraet in der umgekehrten o.g. Reihenfolge zusammengebaut. Dabei aufpassen, dass die eingebauten Draehte und Widerstaende nicht irgendwo eingeklemmt werden. Man kann dazu die Draehte und Widerstaende mit Klebeband so ueber die Platinen fuehren, dass dies nicht passiert.

Das wars schon !

Falls das Geraet nun noch funktionieren sollte, kann man mit dem 9600er-Vergnuegen beginnen.


Aber im Ernst: Der Umbau ist wirklich nicht besonders problematisch und kann von jedem vorsichtigen nicht-Steckdosenamateur erfolgreich durchgefuehrt werden.

Wenn einem Umbauer Verbesserungen, oder ein gaenzlich anderes Vorgehen einfaellt waere es nett, diese Gedanken in der Rubrik 9600Bd Allen zugaenglich zu machen !

Ich verwende ein TNC2H (ufb!) mit den Filterstellungen 5:0 6:0 7:1 8:1 9:0 (empirisch gefunden, vermutlich nicht optimal ..)
Fuer die PTT-Umschaltung wird der entsprechende Anschluss des TNC mit der MIC-Buchse des FT470 verbunden. Das TX-Delay muss so bei ca.20 eingestellt werden , d.h. 200ms. Dies ist im Vergleich zu wirklich optimalen 9600er-Geraeten sehr langsam, aber es geht trotzdem recht ordentlich.

BER-Tests oder sonstige wirkliche Messungen habe ich bisher nicht gemacht.
Aber man kann sagen, dass es auf jeden Fall mit den hiesigen Digis DB0IZ-9 und DB0AMU(etwas besser von hier) reichlich gut geht. Es gibt ab und zu mal Rejects aber die gabs auch schon bei 1200Bd ..
Alles in Allem hat sich der Umbau voll gelohnt !

73 + viel Erfolg !

de Andreas in Rheinbach nr Bonn. DL2KCL @ DK0MWX

19-07-1998 FT-470 9k6 mods

sorry but I didn't realized that the german discription of the modifikations have no use for you. I hope my english is not too bad to translate it into proper english (that may help you). So know my try:

First you have to get the transmitter unit with the BNC connector on it out of the ft. You have to made the connections to pin 1 and pin 10 of the 430 PLL UNIT (it ist printed )on the rear. Pin 1 is ground an pin 10 will be the new RX. Use aprox. 10 cm cables.

Know the TX: You can reassemble the unit because the point you need is on the front of it. What you need is pin 11 on IC 10487 (it is under the shield). Pin 1 of 10487 is marked with a dot and it counts against clockwise.
The guy who have done this recommended to use 10KOhms resistors in line. The TX switch is like in 1200bd packet.

So Peter, i hope this will help you.
As you can see I have some problems in finding the right word for the electrical things ... sorry.

73, 55 from Carsten [email protected]#BLN.DEU.EU

19-07-1998 Full Reset

Effect: Severe! :-)

  1. Make hard (paper) copy of all memory info
  2. Turn radio off
  3. Hold down VFO and MR and turn radio on
  4. Replace all memory contents
This will reset the auto repeater offset function, so you will need to re-enable it if you use it. This will also disable (mask) all memories except #1, so you will have to enable each of them by hand.

Attributed: Yaesu

19-07-1998 FT-470 Clone Mode

Effect: Allow editing of transmit and receive frequencies.

1) Turn radio off.
2) Hold down F key and turn radio on.

Result: All segments of display are turned on. The radio will send data out the microphone tip when up-arrow is pressed. The radio will receive data when the down-arrow is pressed.

Bugs: I have yet to hear of someone who has done this successfully. Please tell me if you know how it works!

Attributed: [email protected] (William J. Szarek)

19-07-1998 1750Hz tone burst

FT470's in the UK come with the 1750 Hz tone burst option built in. It is on a tiny sub card that is wedged in down the bottom at one side. I bought one from the UK distributors and figured out how to connect it when I got back to the US. As far as I can tell my mod is the same as would be done if it was officially installed although the service manual doesn't show where to connect it. It has just 3 wires, power, ground and audio out. It is activated by applying power using the small button above the PTT so you can press both at once to call and then slide your thumb down to release the tone button.

The board consists of a 2*color burst freq xtal and a 74HC4060 CMOS oscillator divider giving 7.16MHz divided by 4096 = 1748 Hz. The chip is surface mounted so they can get the whole thing down to less than 0.5" square.

Attributed: gingell%aurfs1%[email protected] (Mike Gingell)

19-07-1998 Opening Battery Cases

I`ve opened several FNB-x cases in order to replace the cell pack. The procedure that I've used is very simple, but does require patience to prevent damage to the case:
  1. Cut the white label with a sharp knife by following the case separation line. DO NOT remove the nut on the charging connector.

  2. Pry the case halves apart by placing a thin wide bladed screwdriver into the case line on the label end. It may be necessary to separate the black band from one case half with a knife tip when it is evident that glue has penetrated the joint. NOTE: The black band is permanently attached to one case half.

  3. Use continuous pressure, not excessive force, to separate the case halves. Concentrate the separation procedure on the label end of the case. The steady pressure will allow the glue to cold flow and release its grip.

  4. Yes, a frustration level will occur, but then success will appear as the glue gives up after a few minutes.

  5. Make a note of where the wires attach to the battery and thermal switch. Also note the pack orientation.

  6. Connect the replacement pack into the case and attach the wires per your note in step 5.

  7. Close the pack, charge the cells, attach to the radio for a test.

  8. If satisfied, place a spot (1/2 inch dia) of clear RTV on each side of the cell pack and press the case together and place it under a weight for a short time until the RTV cures. Because of the reduced amount of glue, the case will have a more flimsy feel than previous to replacement, but will perform like the original.

  9. For the next replacement, the RTV will give up much easier than the original glue.
Attributed: Hugh Wells, W6WTU

19-07-1998 Hyperscan Mode on the FT-470

  1. Go into Alt mode by pressing [F] 2 (Alt).

  2. Press the Up or Down Arrow to activate the Memory Scan.

  3. When the Scans stops on a VHF frequency on the Left Display (The Main Band), Hit [F] VFO.

  4. Press the Up or Down Arrow to activate the HyperScan.

  5. To Stop the Function, Press [F] Alt.
A preliminary guess is that there is a software loop underway in the VFO and the Memory Scan features. By pressing these sequences of buttons, the register holding the delay count is changed , resulting in a faster loop.

19-07-1998 Yaesu FT 470 Extended Tx. Side effect from keyboard Entry Mod

26 Sep 91

I discovered a side effect from using the Keyboard Entry Modification... I noticed by accident that when inputting a frequency (from 140 Mhz to 155 Mhz instead of the usual 144 to 148 Mhz range), and setting the standard frequency offset of 60 Khz or none at all), i could Transmit. I used a dummy load on the HT and experimenting further and discovered i can use either the standard offset (- or +) or just plain simplex mode and still be able to Transmit without getting the usual "ERROR" message on the display. I verified the transmission capability by using my Scanner and a Spectrum analyzer with a small whip antenna to monitor the output of my Yaesu FT 470 at work. At the Low Power setting, with a 7.2 volt battery, i was able to get approximately +46db at the 0db attenuation level on the analyzer using from 140 Mhz all the way to 155 Mhz range, so the transmit level at the extended frequency ranges of 140 to 144 Mhz and 148 to 155 Mhz matches the same Transmit level elsewhere in the band. That's 4 Mhz and 7 Mhz respectively on the extended Transmit!!!
This side effect comes about when you use the Extended Frequency Keyboard Entry Mod. That's when you select a VFO and enter "50 Mhz), set offset to zero by entering four zeroes, turning the HT off/on, hitting FM key and then REVerse key, then RPT to either "-" or "+" and pressing REVerse to select the frequency range(s) you want and storing the Upper and Lower limits...

You might want to try this side benefit yourself and see what you come up with...

I tried to 70 cm side, but the side effect isn't to be found (yet), but i'm still experimenting with the 470.
73 de KC6VKZ