Hello again and happy holidays! With regard to the K2 frequency stability...
Several good points were raised and I realized that I wasn't adequately specific before. The drift I notice is primarily related to warmup and not during normal operation. I will perform the aforementioned test to confirm whether the instability is primarily in the BFO or PLL oscillator. However, the biggest drift occurs after the rig warms up. Heavy CW operating with the KPA100 brings the temperature very high and this large increase in temp is necessary to make the rig drift in frequency any more. Of course, the distinction between warmup and operating drift becomes academic if one turns on the rig from a "cold" start and start operating heavily right away. :) More commonly, I find that I operate outdoors or somewhere where ambient temperature is cold, run CW at 100 watts and then drift somewhat shortly after the "cold start". Again, I suspect that this is due to "warmup" drift and not some large drift attributable to a malfunctioning temp- compensated PLL. On average, from 60 F to warmup the freq at which I zero beat WWV drifts down an extremely predictable 50 Hz. From normal operating temp to high temp (e.g. 100W CW operation sufficient to kick the KPA100 fan to high) the WWV zero beat frequency will move another 20-30 Hz, for a grand total of 80 Hz relative to a "cold start". There is never any unpredictable change in zero beat frequency beyond this. Once the rig reaches full operating temperature the drift is never greater than 10 Hz. So it seems that the rig is operating within spec and I have nothing to worry about, save to calibrate things so that the radio zero beats WWV at operating temperature. I will confirm this by running the test to differentiate between PLL and BFO drift. Correct? Happy holidays! Adam, N1KO _______________________________________________ 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
