Chuck, Since you have a 'scope, I would suggest you remove the PA transistors from the picture and see if the oscillation persists. You can easily de-solder T3 which will remove voltage from the PA collectors. If you still have the oscillation at the base of Q7/8 (or at the collector) of Q6, then you can more easily troubleshoot it without fear of damaging the PA transistors. Q6 can similarly be taken out of the operating condition by removing a choke or resistor. I don't have the schematics with me while on vacation, so you will have to find out which one on your own.
73, Don W3FPR C. J. Hawley wrote: > Yes the W6 point gets 8 volts either thru the diode D2 or D6 depending on > whether in receive or xmit. I think I have an oscillator at Q5-Q6. I am > checking all the feedback chokes and capacitors. I may need to unsolder C118 > and see if it is infact a capacitor inside the shell and maybe also C120. > RFC6 checks ok, R49, R470, etc. > Thanks for the interest and help. > > Chuck, KE9UW > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
