Back in 1977 there was a circuit published widely that claimed to
correct drift in a vfo by sampling the output, downconverting it,
comparing it with a crystal oscillator then correcting a varicap in
the vfo. Has anyone ever tried this? How well did it work? This
circuit, if it works, could be resurrected and bring a lot of the
older Boatanchor Rigs back on the air. It was called an FLL or
Frequency Locked Loop and was not very complicated.


Tony WA6LZH