[R-390] 2nd LO xtal frequency

[Alan Victor]

Hello Bob, Craig, and all.

I agree with the shift in frequency about 1000 ppm. I was quite surprised.
A simple measurment of course if you believe your PTO and 17 MHz 1st LO are
spot on is look at the error on the kHz dial against WWV. However, I did
measure the 2nd LO through a small 10 pF series cap. Yes, I pulled the
oscillator a little but the zero beat shift was just 100's of cycles. A
better method, form a small close field probe by soldering the center
conductor of small coax, i.e. RG174 or better quality if you have it, to
its shield. About a 0.5-to-1inch loop is all you need. The pigtail coax has
a BNC on the end. I have a 40 dB gain preamplifier and run the preamp
output into your counter. Doing a direct count, the 13 MHz xtal (for 10 MHz
Rx) measured 12.986958 MHz. At this point I am searching the junk box and
see what I can come up with for these various bands. Then its on to other
problems.