FT-73r  Mods
 

Extended frequency for FT-23,33, and 73                                                            
Extended Frequency Enhancements for the Yaesu FT-23R(2M), FT-33R(220), and FT-73R(70cm). (Revised)

Greetings and hello radio amateur operators.

The topic is increasing the functional frequency coverage of what has been probably Yaesu's most popular handheld tranceivers.

To save manufacturing costs, Yaesu engineers designed multiple personalities in the same CPU module found in the FT-23R, FT-33R,UHF FT-73R and the FT-2008/7008 tranceiver. The FT-2008/7008 tranceiver is the commercial version of the Ft-x3R series.

Unique features of this mod include
 
  • 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.
How to do it:
 
  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.

     
(**)NO FREQUENCY READOUT

Removal of the solder bridge labeled number nine will activate the commercial side of the CPU module. To flip to the amateur mode, you would press F UP Arrow. To flip to the commercial mode, you would press F Down Arrow.

 
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
+=+=+=+=+=+=+=+=+=+=+= 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 =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
Same chart as above, but I wanted to add my experience of the Yaesu FT-33R 220 Mhz radio.
When I removed number 7 and then did a cold reset , 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.

 

9600 BPS with Yaesu FT-211RH

                       MODS FOR FT-23 / 73  / 211
                       **************************



                      9600 BPS with Yaesu FT-211RH
                     ----------------------------

RX AUDIO:
---------
On the RX "IF UNIT" (sub board F2869104) connect the screened lead inner to
the TK10420 IC pin 9 with the outerscreen to pin 15. Caution should be taken to
solder these if soldered to the underside of the board.

TX AUDIO:
---------
On the rear of the "MAIN UNIT", a small potentiometer will be seen (peak devia-
-tion adjust.). Unsolder the leg nearest to the rear of the set, and connect
the inner of the screened TX leads to this point, the outer to the earth plane
adjacent to this point. To ensure that the 9600 bauds modem is terminated in
the required impedance, it is essential that a suitable terminating resistor be
placed across the screened lead inner/outer (a 560 ohm resistor); this may
usefully be done at the FT-211RH potentiometer connection.

No further adjustments need to be made to the radio. On the tested modem a
suitable level of 2.5 kHz deviation was achieved with one third rotation clock-
-wise of the modem TX AF level potentiometer.


YAESU FT-23R case disassembly:
------------------------------

1)  Remove the black screws from the top panel of the radio.
2)  Remove the knobs.
3)  Remove the black screws from the rear panel 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 panel of the radio.
7)  In the left of the microprocessor and battery are several printed circuit
    jumpers. The jumpers labeled 7, 8 and 9 are for the frequencie mods, like
    explained in the following.
8)  Re-assemble the radio in the reverse order of these steps. 
9)  The Microprocessor will loose all what the memory contains.


YAESU FT211/23/73 band mods:
----------------------------

The uP's in the FT-23/73 and the FT-211 can be set for many frequency and
memory mode combinations. These modes are controled by the jumpers (solder
pads) marked 7,8 and 9 on the "CONTROL UNIT" board of either radio. Here is a
list of what is possible:

      JUMPER         FREQUENCIES
   7    8    9         COVERED

  open open  in     140 to 164 MHZ
  open  in   in     140 to 160 MHZ
   in  open  in     144 to 148 MHZ
   in   in   in     144 to 146 MHZ
  open open open    220 to 550 MHZ
  open  in  open    440 to 450 MHZ
   in  open  in      50 to 300 MHZ
   in   in  open    430 to 440 MHZ

The FT-211 has separate VCO's for transmit and receive and will lock over about
38 MHZ from approx. 130 to 180 MHZ. The FT-23 has only one VCO and the overlap-
-ping lock range (Xmt & Rcv) is about 25 MHZ from approx. 135 to 175 MHZ. Don't
forget, if you adjust the VCO you must realign every electronically tuned stage
in the front-end of the radio. The transmitters can be tuned for somewhat
higher power output above 164 MHz but at a great power loss at 2m.

The non-amateur (commercial) memory mode will cause these functions changes:

 1.When in the MR mode, the channel number will be displayed instead of fre-
 -quency. You can toggle back to the original "amateur" mode display by pres-
 -sing F<up-arrow>. Pressing F<down arrow> bring 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<Pri> 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.


FT23/73 in packet-radio:
------------------------

If you want to work in packet-radio, open jumper 10 to dissable the battery
save.
 


 

ATTENTION
The KB2LJJ takes no responsibility for any damage during the modification or for any wrong information made on this modification.