[Elecraft] SW broadcast to calibrate against.

[Ian White GM3SEK]

W5FTD wrote:
>Let me ask this again.
>
>Are you saying, that since the mixer signal is a multiple of the TCXO
>freq

"Multiple" isn't quite the right word, but every synthesized signal in 
the box is directly proportional to the TXCO frequency. If the TCXO is 1 
ppm high, for example, then all frequencies derived from it will have 
that same +1ppm error.

>that any errors in the TCXO will be magnified as the ref signal
>goes higher in frequency.  This will then "magnify" the difference in
>audio note of (say) 10 MHz vs 20 MHz for the same TCXO setting. A one
>cps zero beat error at 10 MHz will be 2 cps at 20 MHz (or some such)?
>
You got it. So, if you can adjust the REF CAL frequency within 1Hz at 
50MHz, then at 1MHz it will be within 0.02Hz.

That's the basic principle, anyway. There will be some small errors 
introduced by the calculations in firmware, as Ron pointed out; and in 
the longer term the TCXO will drift.


-- 

73 from Ian GM3SEK