1. Remove the 3 screws from the top of the radio.
   
   
2. Remove the dial knob
   
   
3. Remove the 2 screws from the back of the radio.
   
   
4. Remove the battery
   
   
5. Remove the 6 screws on the bottom of the radio, where the battery attaches.
   
   
6. CAREFULLY remove the front of the radio.
   
   
7. To the left of the microprocessor and battery are several printed circuit pads. The pair labeled 7 will have a blob of solder across them. Using a small soldering iron and solder wicking, remove the blob of solder.
   
   
8. Re-assemble the radio in the reverse order of these steps.
   
   
9. The Microprocessor will PROBABLY reset all the memory contents.
   
   
10. Operation of the radio remains the same, except that the transmit and receive coverage will now extend from 140.000 Mhz to 164.000 MHZ.
    
    

      JUMPER         CONFIG                DISPLAY MODE
   7    8    9       NUMBER

  open open  in        1        140 to 164 MHz, amateur mode
  open  in   in        2        140 to 160 MHZ, amateur mode
   in  open  in        3        144 to 148 MHz, amateur mode
   in   in   in        4        144 to 146 MHz, amateur mode
  open open open       5        220 to 550 MHz, commercial mode
  open  in  open       6        440 to 450 MHz, amateur mode
   in  open  in        7        50 to 300 MHz, commercial mode
   in   in  open       8        430 to 440 MHz, amateur mode

1. When in the MR mode, the channel number will be displayed instead of frequency. You can toggle back to the original "amateur" mode display by pressing F. Pressing F takes you back to commercial mode. However, when switching from D to MR, the display will always revert to the commercial mode.
   
   
2. The function of the Dot button will be exactly reversed. That means now you can press just one button (Dot) to get into or out of the Primary function. The Pri funtion (in memory mode) will be indicated by a large "P" on the left side of the display.
   
   
3. The only indication of low power operation is in the memory mode. A "C" will appear in the upper left corner of the display (where the primary "P" used to be). The bargraph will always read 100%.
   
   
4. The band scan is now even more useless. The uP will painfully count from 50 to 300 MHz.

• the just say Mao feature (**)
  (NO FREQUENCY READOUT: Ch 1 thru Ch 9 appear on your display.
  Great when you aren't looking and some fellow ham tries to rip off your simplex frequency)
  
  
• the GREAT WHOPPER
  (opens the CPU to 50-300 Mhz or 220-550 Mhz coverage. Full (.100 Mhz to 999.9995 Mhz) adjustable freq coverage available so far only on the FT-33R;this doesn't mean you can actually transmit but the Activity light goes in TX and you get a good fake RF bargraph that indicates that you can transmit on 750 MHz.

1. Contemplate invalidating your warranty. No beginners beyond this point. If you don't know how to solder, don't learn here. Ask an elmer to assist.
   
   
2. If you treasure your memories, write out your contents of your radio on a piece of paper. When you make the changes, the CPU runs a small diagnostic and see that the jumpers have been changed. It will ERASE ALL PRIOR SETTINGS.
   
   
3. Dissassemble your tranceiver.
   
   
4. Find the line of solder connections running down the CPU board. GENTLY move all wires aside so you won't melt them.
   
   
5. Using solder wick and a Good low-power soldering Iron, see chart. Read special notes for the FT-33R.
   
   
6. Rebuild radio and count your blessings.
   
   

+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
+=+=+=+=+=+=+=+=+=+=+= FT-23, FT-73R Chart =+=+=+=+=+=+=+=+=+=+=+=+=

   50 to 300 Mhz spread        220 to 550 Mhz spread
   --------------------        ---------------------

   Open bridges 8,9  Open bridges 7,8,9

+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
+=+=+=+=+=+=+=+=+=+=+=FT-33R Chart =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=

, the CPU cleared and showed me a L and a freq. I put .100 in.
Press D/MR. Then a U appeared. I turned the VFo knob until 999.999 appeared. Press D/MR.

I also had to reenter the Repeater Split to the proper value.

On the VFO, I could QSY down to those limits (using F UP/DN) and listen to my local Channel 13 on 215.720/.660.

Yes, 216-220 Mhz is available with this mod. Great if 216-220 is the next 220 subband.

Notes
1 Cold Reset of the CPU Board.
With the radio upright and your nose pointing at the CPU board, look at the Lower Right Corner of the CPU chip. You will see two parallel SMT resistors. Below them is a screw with possibly a paper washer. To the right is a SMT device (it's a cap) with a pointed end facing Left. Ground that point to the screw or to the case with a flat screwdriver. Awhile doing that, cycle on/off the radio to ensure a good reset. Remove screwdriver and then reassemble radio.

Dedicated to:
----- the knuckleheads in Barry Electronics who said it was impossible.
----- Yaesu Tech Support who claimed that there are no RESET circuits in their radios, when their schematic diagrams say otherwise.



22-08-1998 Yaesu FT-23R 2m walkie talkie anthology

by Frank Reid, W9MKV1
As the happy owner of several Icom radios, I went to a hamfest intending to buy a new IC-u2AT but my friends talked me into a Yaesu FT-23R instead. I'm glad!

Construction: The case is die cast metal (u2AT is plastic) and is well protected against weather except as noted below (see DTMF). The carrying case is rather unattractive, made of odd smelling material; I don't trust its belt loop or Velcro flap closure. I removed the belt loop and cut a slit for the (optional) belt clip. I used a paper punch to round the ends of the slit to prevent tearing.

Human Engineering: Yaesu did an excellent job of making a complex radio easy to operate. I especially like the rotary knob which selects presettable channels (10) or tunes in 5 or 10 kHz steps. Six keyboard buttons (one is an alternate function key) control programming and scanning. UP/DOWN keys duplicate the knob's function, and have an alternate 1 MHz "giant step" capability.

The keyboard lock function does not affect the rotary switch. Keyboard lock (indicated by an "L" symbol on the display) is remembered when the radio is turned off (good idea!). The FT-23R has odd offset capability. A button above the transmit switch unsquelches the receiver (transmits tone burst on European model).

There is no display illuminator, which would be practical with knob tuning; display lights in keyboard controlled rigs are nearly useless when it's too dark to see the keyboard.

Audio:
Not surprisingly, the tiny flat speaker isn't very loud, and rattles terribly at full volume. Speech from a belt mounted FT-23R is easily drowned out. It fits a shirt pocket, somewhat inconveniently with DTMF2 and large battery installed. It can be secured in a shirt pocket by hand lanyard attached to epaulet of military style shirt, or longer string with sliding cord lock, over the shoulder with loop around opposite armpit.

Antenna:
Standard BNC connector. The "short rubber duckie" supplied with the radio is more flexible than most similar antennas, and appears very durable.

DTMF:
The optional Touch ToneTM generator mounts between the radio and battery, plugs into a 4 pin internal socket, and is attached by 4 long screws. It makes the radio about 3/4 inch taller, and 1/8" thicker. Other accessories, e.g., the mobile power adapter, also mount between radio and battery; one envisions a future fully equipped wlakie-talkie 3 feet long!

The delicate looking membrane type DTMF keyboard is not sealed around the edges. There could be trouble if it takes water. The DTMF keyboard has neither tactile nor audio feedback, however, an LED lights when a button is successfully pressed.

CTCSS:

3 The optional subaudible tone squelch module provides "PL" encode . Actual tone squelch frequency is displayed during programming (nice!). The tiny module ($61) mounts above the battery attachment plate, and does not extend the radio's length. CTCSS modes are "Encode" and "Encode/Decode" but no decode without encode.

Memory Cloning: A cable from the earphone jack of one FT-23R to the microphone jack of another transfers memory contents (useful for emergencies). A switch on the bottom of the radio (accessible by removing the battery) puts the radio into clone mode. You cannot reach the clone switch if the DTMF module is installed.

Scanning:
The FT-23R has CHANNEL-SCAN (all 10, with lockout), PRIORITY SCAN (checks ch. 1 every 4 seconds) and BAND SCAN (no presettable limits). There is no timeout resume scan mode. Scan rate is 2 preset channels per second. Band scan is much faster; 1 MHz in 9 seconds @ 10 kHz/step, 18 sec @ 5 kHz/step. I encountered NO "BIRDIES" (spurious receiver responses) during 140-164 MHz band scan, with a shielded 50 ohm dummy antenna.

Instructions: Well written in good English, but the book contains NO schematic or block diagram (Boo!). The receiver first IF is 10.7 MHz (not listed in specifications). Being careful not to transmit, I connected the antenna jack to a spectrum analyzer and found a -6 dBm (75 ohms) local oscillator signal 10.7 MHz below the receiving frequency. The spectrum analyser revealed a unique signature: the FT-23R's battery saver feature turns the receiver off (for 600 ms) and on (300 ms), in a cycle beginning a few seconds after the receiver is squelched (and not scanning). I have observed no bursts of TVI when the PLL relocks. Knowing the IF allows using the image response trick to listen to ATC while at airports. (Multiply first i.f. by 2, add to the desired aircraft frequency, tune the radio to the sum; AM comes through weak but readable.) I tried it at the local airport; the Yaesu's FM detector does not perform nearly as well on AM as does the Icom IC-02AT or IC-28H.

Extended Frequency Range:

"Circumcising" the FT-23R is remarkably simple. Removing one solder blob (pad #7, clearly marked, 10 o'clock position from the speaker, 9 o'clock from the microprocessor) lets the radio receive and transmit from 140.0 to 163.995 MHz. Too bad it won't do National Park frequencies.

The two circuit boards with surface mount components are uncluttered. When opening the radio, be careful not to lose the tiny coil spring inside the battery release button. I haven't measured receiver sensitivity, nor do I know about performance in big city RFI; the FT-23R is considerably more sensitive at 162 MHz weather frequencies than is my modified Icom IC-02AT.

Power:
Receiver drain is 19 mA in power save mode. The FT-23R operates at any voltage from 6 to 15v. Three rechargeable battery options offer small size, long duration, or high power. Rated output at 7.2 v is 2.5 watts; a friend's rig and my own both produce 3.5 w with FNB-10 (7.2 v, 600 mAH) battery packs. Two replaceable cell battery packs are available (six AAA and six AA). Alkaline cells are invaluable for emergency service; AA cells are more cost-effective than AAA's. The three NiCd battery packs require three different wall-charger types (15-hour charge time). The optional automatic fast charger charges any NiCd pack in 5 hours.

Speaker Microphone: One is available from Yaesu. The Icom speaker-microphone works with Yaesu transceivers if a resistor inside the spkr-mic is replaced with a lower value, and It still works with Icom radios afterward.

My FT-23R, with DTMF and 7.2 volt 600 mAH battery, was $249 from some nice folks from Kansas City who didn't soak me for sales tax, at least overtly.

MORE ON THE YAESU FT-23R

by Bob Parnass, AJ9S
Frank's comments on the FT23R walkie-talkie were persuasive. I bought an FT23R, an extra 7.2 V 600 mAH battery, mobile DC adaptor, PL encode/decode deck, and the AA dry cell case.

I filled the $12 AA dry cell case with six 550 mAH Sanyo NiCd batteries, purchased for an additional $12 at a hamfest.

The Yaesu belt clip looks flimsy, so I bought an ICOM belt clip (for the ICOM mini-talkie) and reamed the holes to fit the FT23R. The spring steel ICOM clip is $2 cheaper and fits my belt better.

If I had bought the Touch ToneTM pad with the radio, it would have cost and additional $30. If pad is $50 if purchased separately.

Since the same radio case is used in the FT23R and its industrial cousin, the FT23R is built rugged, much more so than its Kenwood and Icom competitors. Reminds me of how my Motorola HT220, or a GE Pocket-Mate feels. The rubber gasketing on the case top and side is impressive. In contrast, the case bottom, near the battery plate, is open, although dust should be prevented from entering as long as the battery is in place.

My fingers aren't big, but seem huge when trying to push the closely spaced rubber buttons or twist the knobs on the Yaesu.

After verifying that the stock radio worked, I carefully opened the case, then made the modification for full 140-164 MHz coverage. There appears to be no modification to enable out of band receive without transmit. This made my dealer nervous, and fearing FCC action, he posted a sign warning that no out of band receive modification was available. The tiny surface mount components on the circuit boards mark a turning point in amateur radio construction, when owners may no longer be able to service their walkie-talkies.

I connected the FT23R to a variable voltage, current limiting bench power supply. The receiver section must have voltage regulation, as increasing the voltage input from 7.2 to 13.6 VDC caused no difference in receiver current consumption.

The fastest charger available for the FT23R is a 5 hour unit. It contains a timer, rather than the more sophisticated thermistor and temperature sensing arrangement of the Kenwood and Motorola rapid chargers. Rather than buy the fast charger, I use a bench power supply connected though a power resistor, and adjust the current for 180 mA, the appropriate 5 hour charge rate.4

When in battery save mode, the current consumption alternates between 5 mA and 50 mA.

Based on comparative S-meter readings, the 4.5 inch flexible antenna supplied with the FT23R doesn't hear quite as well as its longer counterpart.

The method of locking out channels is cumbersome, and it's too bad that channel 0 cannot be locked out of the scan. There must have been an early batch of 23R's with a firmware bug, as my unit was packed with an errata sheet, which said early units behaved differently when using the priority mode on certain channels.

I just purchased an FT23R, and like it very much. It was chosen as the least expensive 2 M walkie talkie with over 3 memories available at the Rochester (NY) Hamfest. I considered the DTMF pad as part of the unit and price. The unit turns out to also be rugged and well built; audio is excellent, and size is handy. The PL does need to be purchased as a single (very simple) unit. Installation of the PL is shown in the manual, and is simple. The microprocessor does all the programming and remembering of PL frequencies along with the transmit and receiver frequencies.

My only reservation is the relative complexity of the controls -- that seems to be common in modern ham gear -- and the size of the knobs and buttons. There is a lot more functionality than you would ever expect in an walkie talkie. I would also recommend purchasing the quick charger and the large battery pack.

I hope you enjoy the unit as much as I have.