[R-1051] Easy frequency standard calibration

[David Wise]

Only three prerequisites:

1. Strong clear reception of one of the WWV signals

2. A working radio

3. A dual-trace oscilloscope

Put the radio in ISB mode and tune in WWV.
Route USB to one scope channel, LSB to the other.
Trigger the scope on channel 1 and adjust for a stable trace.
Adjust the frequency standard so the channel 2 trace is stationary.

This avoids the problem of infrasonic beat notes, and you can
do it without a GPSDO or other high-accuracy standard.

Cheers,
Dave Wise