[hpsdr] Fixed SAW Oscillators

[KA2WEU at aol.com]

In a message dated 2/27/2008 3:17:42 A.M. Westeuropäische Normalzeit,  
chris at chris-bartram.co.uk writes:


If  it's designed well, a low-noise VCO based on a quarter-wave ceramic 
coaxial  
resonator could be locked to the 125MHz oscillator using a sampling phase  
detector (or a suitable harmonic mixer...). I'm still working on that. A  
phase/frequency detector isn't suitable and a divider chain would have its  
own noise contribution. If the loop bandwidth is kept reasonably large and  
the oscillator stays within the lock-in range of the loop, that could make  a 
relatively simple and compact 1GHz reference.

Vy  73

Chris
GW4DGU



That is correct, a harmonic sampler/mixer and a VHF crystal like 125 MHz  
based, and a modern multi resonator based VCO will do the trick. I never need  
exactly 1GHz but some offset to avoid spurious signals.
 
73 de Ulrich, N1UL



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