I recently noticed some drift on my K2, but it's not happening the way
I'd expect. This morning it happened again, as follows. I turned the K2 on the K2 with volume turned down almost completely and left it that way for a couple hours, tuned to 7040 kHz. Then I turned volume up to a normal listening level and immediately tuned down to a CW signal at 7024 kHz. Tuning resolution was set rather course at 100 Hz. When I let go of the main tuning dial, within seconds the frequency starts climbing up the band at a rate of about 100 Hz every 10 seconds (rough estimate). I changed tuning step to 1000 Hz, and the apparent drift kept happening, but this time in a 1000 Hz step *within the same time period as before*. It's almost as if my encoder is drifting... not the radio. After a few minutes things seemed to stabilize. I just tweaked the main dial again, and drift started, this time in the other direction. The rig seems to go into these drift fits only when I tweak the knob. I've never seen this behavior on my K2 before. It's been very stable since I built it more than two years ago (serial number 4958). A couple weeks ago I did a very thorough realignment of everything (peaked inductors and caps, tuned filters, calibrated S meter, measured MDS, etc.) using test oscillator and calibrated noise generators ('til I fried my N-gen.. D'oh!). Top to bottom tune-up. I'd swear it sounded better than ever -- or maybe that was just the conditions on 40... but this drift seems to coincide roughly with that realignment. Maybe a complete coincidence. Help? --Andrew, NV1B _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Andrew Moore wrote:
> When I let go of > the main tuning dial, within seconds the frequency starts climbing up > the band at a rate of about 100 Hz every 10 seconds (rough estimate). There *was* a problem like this with an old version of the firmware. If this is the cause you can update the firmware or make a simple hardware mod. See <http://www.elecraft.com/Apps/Alert16.html>. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Drew,
Have you ruled out the simple obvious? Felt washer is no longer putting enough friction on the VFO knob to keep it still? -- JT Croteau, N1ESE - Manchester, NH (FN42gx) _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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