[time-nuts] Why using HP5370 ext-ref is (maybe) a bad idea
magnus at rubidium.dyndns.org
Sat Mar 1 05:39:28 EST 2014
On 01/03/14 01:47, Bob Camp wrote:
> There is a fairly involved alignment process for the multiplier chain. My *guess* is that small tweaks to the alignment could impact these timing spikes. Sub harmonics tend to produce multiple zero crossings that show up as periodic jitter in the output. The offset input peaks may be a better thing to look at as you tweak the multiplier than the “official” adjustment procedure.
It was exactly what I was hinting about, it may be a better procedure as
it addresses the actual precision rather than indirect phase noise
measures. Just doing phase-noise measures rather than spectrum analysis
helped to illustrate the problem.
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