Re: #synth ref frequency #synth

Alan G4ZFQ

somwhere i read about, that the reference clock of the Silab synth in a U3S MUST be at 27 MHz.
But i think, i heard that there is another cause.
Something with the 1.4648 Hz spacing of the wspr tones ?
Hans has said that a 27MHz is required to make the tones exact.
I do not know if anyone can say what amount of error is permissible with WSPR but I use a 26MHz TCXO with no apparent disadvantage. (But it is difficult to be certain, maybe I do get missed sometimes?)
The U3S will operate with a wide range of frequencies, I've tried 10MHz.
But I do not know of anyone properly testing for signal purity.

73 Alan G4ZFQ

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