At 10:10 AM 6/8/2006, Alan wrote:
Hi Bill fascinating info......would it be correct to say that with the
magnitude of Mike's error, it is the result of a slightly high reference
oscillator ??
It looks to me like the 20 Mhz reference was drifting around while he was
taking the measurements (possibly his audio measuring system was drifting
also, but that is less important).
When I do these measurements I use an external standard (locked to GPS)
in place of Kenwood's internal oscillator, and I also drive the LF DDS
synthesizer from the *same* external standard - so the audio output from
the radio is rock solid. The only uncertainty is the sound card sampling
rate (which I check often against GPS).
For a quick and dirty calibration of the TS850, one can tune in WWV's carrier
on 15 Mhz (CW mode), measure the audio tone out, and trim the
internal reference
osc so the tone output is 800 Hz. That'll get you to well within 1
Hz on LF, at
least for a while, hi!
Bill VE2IQ
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