Subject: FT23, 33, 73 extended range mods
From: [email-masked] (robert.f.casey)
Date: 1 Dec 91 03:09:53 GMT
Newsgroups: rec.radio.amateur.misc

copied from packet:
w2fwd.ny.usa.noam
allbbs
Subject: Yaesu FT-23,33,73 Mods Revised

---------------------------------------------------------------------
WARNING: Out-of-band operation is unlawful.
         This electronic document is for informational purposes only.
 Try this at your own risk.     
---------------------------------------------------------------------

>From the Bench of: KB2Jpd
======================================================================
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:

0. 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.

1. 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.

2. Dissassemble your tranceiver.

3. Find the line of solder connections running down the CPU board.
   GENTLY move all wires aside so you won't melt them.

4. Using solder wick and a Good low-power soldering Iron,
   see chart. Read special notes for the FT-33R.

5. 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   <see below>, 
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-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-NOTES-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.

Special Thanks to:

Ken, N2MUK, for playing the guinea pig.
Bobbie, KB2IFJ, for playing surgeon when I told him not to.

Please don't play with matches.
W2Fwd.NY.USA.NA
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Note: I haven't tried or verified this, proceed at your own risk.  And
don't transmit out of band!  WA2ISE