At 12:46 PM 1/29/2009, Ron D'Eau Claire wrote: >Wow, Pete, what a puzzle! > >You might make up a little probe consisting of a wire connected to your rx >antenna input that you can touch to the circuit parts. If it has to be a >long lead, use a bit of coax so random signal pickup won't confuse things. >If your rx input is grounded for d-c, put a small cap in series - anything >from .001 to .1 should be FB - to provide d-c isolation. Then touch it to >the collector of Q1. You should find your S-9 signal. If not remove coupling >cap C4 and try again. > >If you now have signal, there's a ground somewhere in the attenuator that is >killing the signal. If not, you have a defective transistor (although that >is high unlikely given that you've established that the voltage on the >collector is correct.) > >Once you have the signal at the collector, start working through the >attenuator until you lose it.
A very neat idea, Ron - I'm going to use this one a lot! I lifted one leg of C4, the output coupling cap, and took a look at the signal level at the collector of the transistor oscillator. It is very, very low. Is it possible that the RF surge somehow damaged the crystal? I'm running out of components to replace here! 73, Pete _______________________________________________ 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
