Matt, I would first suspect the stability of the voltage regulators. That VFO is tuned with a varactor, if the voltage changes, the frequency will change. If that does not settle it down, I would wind L1 on a new core on the suspicion that the present one is more temperature sensitive than usual.
73, Don W3FPR On 5/5/2011 1:40 AM, Matt Scholz wrote: > Hi - > > I am trying to reduce my K1's VFO drift to an acceptable level. The VFO > frequency drifts up at a rate of about 30Hz/minute (after a 5 minute warm > up). Even after one hour, the drift is still about 15Hz/minute. This is > too much, obviously. > > I have been trouble shooting this with the help of Gary, AB7MY. So far I > have done the following: > > * Removed C2 to isolate D3 from the rest of the VFO circuit. No change. > * Replaced all three VFO poly caps (one at a time). See above. > > I was wondering if anybody had any ideas on how to further trouble-shoot > and resolve this issue... > > Thanks in advance and 73, > > -Matt / W6ZBA > ______________________________________________________________ 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
