[Elecraft] To PLL mod or not

[Ron D'Eau Claire]

Rod N0RC, wrote:

Wonder if I should leave well enough alone? Today I switched on my K2
and while it was "cold" I zero beat WWV, the display read 10,000.02. I
left the rig on, and four hours later zero beat WWV again. The dial read
10,000.06.

I didn't measure BFO drift, frankly I'm not sure how to measure it.
Ideas? ______________________________________________

My K2 exhibits similar L.O. stability in the shack. I'll probably change
those PLL crystals only because I bought the BFO mod kit and Wayne/Eric
included the PLL rocks in it! (If I have trouble after changing them,
it's all their fault!). 

I did buy the kit because it would be nice to have less BFO drift. I
have to let my K2 warm up for 10 or 15 minutes before using the 400 Hz
filter. I've gotten used to doing that and wouldn't think much of it
except that they came up with a "fix" forit. 

 I'd suggest that the easiest way to tell if you have excessive BFO
drift is to see how the signals sit in the passband of your narrowest CW
filter. For the first ten minutes or so, signals are actually down one
side on the response of my filter set for 400 Hz. As the BFO warms up
the signals slowly move up to the center to the passband. You can see it
quite easily on Spectrogram if your ear's aren't sure about what they
are hearing. 

If you don't experience that, I'd say your BFO is plenty stable as it
is!

Ron AC7AC
K2 # 1289