[Elecraft] K2 AC7AC 4 Mhz oscillator setting technique

[Ferguson, Kevin]

Ron, AC7AC writes,in part, about his excellent 4 MHz test method:

>...No "fancy" test equipment required, just a receiver capable of receiving
>WWV on 20 mHz. ...

Seems to me that this reciever could be the UUT (K2) itself, tuned to 20
MHz!  
You might need to attenuate the antenna signal some, or solder a small wire 
antenna (2-3")to the MCU 4 MHz pin to get the signal strength to match close
enough 
for a good beat. Maybe just running a wire from the antenna jack over near
the 
control board MCU would be enough.

It has been pointed out, the 4 MHz crystal accuracy is only important at the
time
the cal pll procedure is run, so such antenna could be removed after the pll
alignment
procedure is run...however, I'd worry that the 4 Mz being different might
cause some 
trouble with the BFO alignments.

Ron's procedure is even more elegant than my using the K2 to beat my
counter's 10 MHz
reference oscillator against WWV while adjusting C22 so that the counter
reading matched
the built-in counter.

BTW, I find when I get fairly close to exact zero beat, it works best for me
(YMMV) to
turn the ALC back on, and watch the beats on the S meter.