KL503 junk

[Klondike Mike]

I can concur with your finding. Initially got good reports but I'm assuming people weren't listening close enough. Started to get negative reports from better ears and unit is now back in the box.

At some point in time I pulled it out of the box and tried again. I found that a max. input of 10w on SSB was what was needed to get good reports and around 200w out.

 

[Tib2K]

Exit13

This is the kl503 schematic it looks like it has biasing I traced it in red does this look right to you?
it looks odd as it had to pass through the transformer to get to the other fets but I guess it doesn't matter as it is only DC...

@KD2GOE any chance you still have the schematic?

 

[Tib2K]

ok well I have it working good I have been looking at schematic all day comparing most of the RM line of amps.
now talking to my friends and they gave me good SSB auto reports. :drool:

what I did was just disable the pre-driver on the amp and bypass it. i have included a pic.. you can also just cut the pre-driver out and cut R26 and C30 but I didn't feel like removing the board...

Again the picture?
In the directions you say just cut the driver out, and cut c30 and r26.

Don't you have to jumper where the driver was to allow the rf signal to continue to flow to the next stage of the amp? what pin to what pin needs a jumper?