Change final to 2SC1969.
If the driver final is a 2SC2029, change it to a 2SC1957.  Some radios
 come with this driver already installed.
Change R123 to a 0.47 ohm resistor.  Do not jump this resistor because
 it could overdrive the final.
Change R58 to a 2.7 ohm resistor.
Replace D8 with 2 1N5817 diodes. One on top of the board and one on the
 bottom. This will prevent voltage spikes between the driver, final, and
 modulation transformer.
Change C71 to a 33uf 25v. electrolytic capicitor.
Place a 47pf disc cap across C57
Place a 47pf disc cap across R55
Adjust L17, L20, L21, L16, and L14 for max RF output.
Do not cut D11. This will cause over modulation.  Adjust VR4 for
 optimum modulation. No more than 110%
Adjust L12, Sometimes stretching gets a "little" more power.

========================================================================
 
  CARRIER MOD (required for amp):

Remove JP36.
Solder a 220uf or larger 25v. Electrolytic capicitor in the holes,
 negative side to final.
Cap with 50 to 100 ohm 1 watt resistor.
The lower the resistor value, the higher dead key will be.

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

VR1.....Recieve gain
VR2.....Signal meter
VR3.....Squelch
VR4.....AMC
VR5.....Transmit power meter 
VR6.....Antenna warning light

L11.....TVI trap-DO NOT ADJUST!

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

RECIEVE BOOST:

If D17 has a resistor (8k) soldered to it, remove it. Solder the diode
 back to the board. This is only on the newer models.
Locate pin 14 of the PLL.
Install a 22k-220k ohm resistor between these two points.
The smaller the value, the more the recieve is boosted.
Mine is wired into my bright/dim switch. you can add a small toggle switch
 if you desire.  I highly recommend a switch. If you are talking to someone
 close, you can't understand them unless this is disabled.

If your recieve audio is weak, check R31.  Replace it with a
1/4 watt 47k resistor. 

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

VARIABLE POWER:

Remove JP36, VR4, and C73 (near the final).
Desolder the orange and brown wire from the RF Gain Controll (RFGC).
Solder the wires togather to restore recieve.
Solder a TIP-120 Darlington transistor where JP36 was removed.
Solder the emitter (rt. leg) into the hole near the final.
Solder the collector (center leg) into the other hole.
Solder a wire from the base (left leg) to the center tag of the RFGC.
Solder a 100 ohm resistor to the bottom tag of the RFGC.
Then solder a wire from the resistor to L6 pot.
Solder a wire from the top tag of the RFGC to the VR4 hole nearest
 the back of the radio.
Mount TIP-120 to heatsink using new hardware and insulating pad.
 Don't forget the heatsink compound. Take extra care not to ground the
tab.

You can mount to the heatsink behind R114 or add your own.  Being a
 firm believer in keeping the components cool, I removed the factory
 heatsink in my radio. I removed the tag on the back of my radio and
 cut out a square section large enough to mount a much larger heatsink
 (3"x2"x1.25" ribbed). My final is mounted to it and my Var. transistor
 is mounted to a 1.5"x.75"x.5" ribbed heatsink. I thought this would
 be better than a fan. Filtered vent holes work fine too. Anything you
 do to keep your finals cool is well worth the trouble.

If your radio has a carrier circuit, and you don't want to remove it
 you can do this. Personally, I don't like this method, but it works:
Desolder orange and brown RFGC wires from board.
Solder a jumper in the holes to restore recieve.
Remove the resistor (dead key limmiter) from the bottom of the board
 that jumps the JP36 modulator cap (220uf 25v.).
Solder the wires to the legs of the capacitor.

This mod is very touchy. You don't have to turn the knob much.

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

Sound Tracker radios require that the sound tracker feature be
disabled before any modifications.  I was sent this mod from a
visitor:
  29WST- RemoveC809 and C821 (C809 and C819 for 25WST) short
pins 1&2 of IC802.  
 
 

  7:09 PM 12/15/01