Adam, You cite 70 to 80 Hz drift from a cold start. That is within the K2 spec of <100 Hz drift typical from a cold start at 25C (77F). If your ambient temperature is lower, you can expect more warm-up drift.
Once warmed up, the drift should be small. Even my stable HP6840 takes about 2 hours to stabilize after I power it on, and I have the MIL version, so there is a big sticker on the front warning that it has this warm-up drift. I just refrain from measuring anything until the warm-up drift has subsided - so I contend that even fine lab equipment is subject to warm-up drift and to expect that a K2 would be totally stable from a cold start at ambient temperature is IMHO being unrealistic. I do not know of any ham gear that does not have some warm-up drift unless all the oscillators are contained inside a temperature controlled ovens. Only high-end homebrew transcievers can achive that kind of stability, to manufacture units like that would be too costly for the general ham market. Or did I understand something incorrectly? 73, Don W3FPR > -----Original Message----- > > As a few people pointed out, I misspoke in my earlier email. > > When I calibrate C22 I immediately run CAL PLL and CAL FIL. > True, the K2 does not directly reference C22 during normal > operation. My calibration of C22 and then CAL PLL and CAL > FIL is all by-the-book. > > That being said, I still do notice a temperature-dependent > frequency drift during normal usage. The drift is > predictable, with the zero beat on the dial I get with > reference to WWV drifting by as much as 70-80 Hz if the > temperature difference between ambient and the max temp the > rig hits with the KPA100 under heavy use is large. The > frequency at which I can zero-beat WWV does not change > unpredictably. The radio consistently zero-beats low (e.g. > WWV zero-beats at 10.000.07) when cold. > > Is this a really big deal? On SSB, certainly not. On CW I > like to zero-beat dead-on with the narrow filters. Perhaps > I'm just being a perfectionist. > > Adam, N1KO > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.26/601 - Release Date: 12/24/2006 11:31 AM _______________________________________________ Elecraft mailing list Post to: [email protected] 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
