Sorry to be a wet blanket, but from my current standpoint, I'd be grateful to find just the one spurious signal from the KPA.
I have literally dozens of spurii on all bands that are S2 or greater. Some read S9+40 and would read higher if the S-meter could indicate that. They all emanate from that dratted HV bias supply and moving between high and low power on the K2's power control doesn't affect the birdie count. I haven't found any that move, either. Turning off Q8, the bias supply osc. transistor, turns off all the spurii. All components have been checked most carefully for value and all have been re-soldered. The KPA was constructed to the latest revision and with R4 at 100k, the bias voltage was just over 140v. Increasing R4 to 220k has dropped the bias voltage to 128v, but hasn't reduced the spurii. They are not entering the K2 via the speaker lead, aux. power or RF connections but are present at rock-crushing levels with just the ribbon cable connected. It's been a great disappointment to find this problem, as everything else has worked beautifully (after minor debugging). I note the various comments regarding the difficulties experienced by others in their attempts to "tame" the situation, so with my limited expertise, I don't hold out a lot of hope. Just in case it's the MAX1406, I'll try lifting one end of D7 to disconnect its input, but after that I'll probably resort to replacing each and every component in that area one by one, in case there's a "rogue". 73 and Season's Greetings to everyone. Dave L G3TJP, who's feeling very sorry for himself just now ;-( Quote: Julius, N2WN Just out of curiousity, after spending some time on 10M during ARRL 10, I noticed a birdie around 28.019/20. Is there a way to eliminate this or move it below 28.000? _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
