I'm wondering if there was any resolution to this problem, first posted just over a year ago, since I observe what I think is the identical problem with my K2 S/N 6982. A related symptom was obvious BFO shift when pressing down on the top cover just behind the A=B push button (for example, to hold the K2 steady while turning off AGC or checking current XFIL setting, i.e., an operation that requires two button pushes). Some loosening and moving of the side panels seems to have resolved this second symptom, but the BFO shift out of the filter center frequency persists.
I'm currently working on KPA100 construction, and would really like to resolve this before installation (still several days away ... now looking at T1 installation!) and would appreciate any thoughts on this BFO shift. Meanwhile, have started tracking BFO freq/Pin 14 voltage per Don's suggestion. Thanks! - Bruce Don Wilhelm-4 wrote: > > > I do have a suggestion - make a series of tests over a period of several > days before doing anything to try to fix it. > You think the BFO is shifting, so find out for certain. Take one filter > that you are not likely to use (like LSB FL4), and do NOT change that > one. Instead, select that filter, enter CAL FIL, tap BAND-, then tap > DISPLAY to see what the BFO frequency is. Record the BFO frequency over > a period of days and see whether it really is changing. At the same > time you make the frequency reading (and without changing filters) > record the VBFO signal voltage - that can be found at Control Board U10 > pin 14. > > > 73, > Don W3FPR > > > Douglas Furton wrote: >> I'm having a problem with my K2 (SN 6761 10W/CW only): I have to align >> the crystal filters almost daily. It seems the BFO shifts by 200 Hz or >> more almost daily. >> > > > ----- Bruce Rosen K1FFX -- View this message in context: http://elecraft.365791.n2.nabble.com/K2-BFO-Drift-Filter-Alignment-tp4236424p5893450.html Sent from the [K2] mailing list archive at Nabble.com. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
