[Elecraft] To PLL mod or not

[k6se@juno.com]

Lou, W7DZN's last post regarding combined PLL and BFO drift was excellent
and enlightening.

I want to briefly reiterate one of the things he pointed out:

BFO drift causes the filter passband to shift and can cause the desired
signal to not be in the passband, while PLL drift does not cause this.

After doing the PLL and BFO (toroid) mod in my K2 (#2622), the BFO drift
is virtually nil.  Using Spectrogram with a 50 Hz xtal filter passband
centered on my 400 Hz pitch marker at power on, no drift was noticed
after 3 hours of warmup.  I'm extremely pleased about this, as it has
cured the problem which caused me to remove my K2 from active duty.

VFO drift was 90 Hz (using 10 MHz WWV) in the same period of time.  This
is the same as it was before the mod.  Still working on this problem.

73, de Earl, K6SE