After finally getting my hands on an 8528S, the marine version, I discovered
that on channel 1, 2182khz the radio transmits in AM mode. After some thinking,
I decided that I could make a land based 8528 do this also, but on all channels.
My main reason was for the 27mhz CB band, but then I realised it may be
popular on the amateur bands as well.

I spent a lot of time studying the manual, burning eproms and general fiddling before
I stumbled on this simple mod. At first I had carrier, but no modulation. Then I thought
that bypassing the crystal filter would give me Double Side Band (DSB) which would
probably do, but that was unsuccessfull. But finally, here it is.

Instructions.

CLICK HERE for pictures showing locations of sections relating to the mod.

Remove both lids of the radio.

Locate the RF Mixer board. It is on the side with the shorter lid and has the 2 VCO cans and filter can on it.

Remove R76 (I just snipped one side which is easier than removing the whole PCB).

Turn the radio over. Locate J2 on the micro-controller board , which is the section with the EPROM.

Run a wire from Pin 8 of J2, via a switch to earth. This is the output from the micro that switches AM
in the 8528S and also when tuning an autotune antenna which is done with AM, not SSB.

The function of this switch is as follows.

Switched to earth is AM mode.

Not switched to earth is SSB, note LSB & USB can still be selected normally when in this position.

The removal of R76 has no other effect on the radio when in SSB mode.