AMC Modification
Add a 8.2KOhm in series with R249 and a 1KOhm resistor across D92 to give more AMC adjustment range.
Super-talk
Lift leg of R-238. Insert a 1N4745 Zener Diode (a 16V, 1 W type), band side up.
Solder the Zener diode to the PCB.
Next, solder the resistor lead you lifted from the PCB to the banded end of the Zener diode.
DOING THIS WILL GIVE YOU FULL MODULATION SWING AT LOW POWER.
PLUS, IT GREATLY INCREASES YOUR RMS WATTS TOO.
Stabilise Talk BackBridge C-155/R-207 junction to the C-187/R-235 junction with a 470K resistor.
THIS WILL DO AWAY WIYH FADING IN AND OUT, PLUS TAKE AWAY ANY SQUEEL IN THE TALK-BACK YOU MAY HAVE.
YOU CAN CHANGE THE LOUDNESS BY CHANGING THE RESISTANCE THE 470K PROVIDES GOOD LOUD TALKBACK.
Channel Expansion Version 1
1) Open up your radio.
2) Find the small circuit board on the left of the radio.
3) Cut the (usually) green wire and tape it off.
4) There is an unplugged connector by this board….plug it in.
5) Near the front of the radio there is a connector marked +10K. Reconnect the plug to the board.
6) That’s it.!You now have 8 bands of 40 channels.25.165-28.755.
Channel Expansion Version 2 (more detailed, but the same)
Remove the bottom cover.
On the left side of the radio (Front panel facing you) look for a red wire on the small pc board. (foil side up)
Unsolder this wire at both ends and dispose of it.
Be certain that the solder pads, from which the wire was removed, are soldered correctly.
Remove the screw holding the board onto the chassis.
On the top side of that board (component side-which was down) there is a row of pins with nothing plugged into it.
There will be a matching plug close by that is lying loose.
Plug it onto the row of pins and replace the screw holding the board to the chassis.
Near the front of the main pc board there will be a small 3 pin plug lying loose.
Plug it on to the matching pins located next to the channel board.
The radio will now work on the C. B. band.
Tweaks
Audio Limiter - R249
AM Power - VR13
