[time-nuts] Basic regenerative-divider questions
magnus at rubidium.dyndns.org
Sat Sep 29 10:31:33 EDT 2007
From: "John Miles" <jmiles at pop.net>
Subject: Re: [time-nuts] Basic regenerative-divider questions
Date: Fri, 28 Sep 2007 21:40:04 -0700
Message-ID: <PKEGJHPHLLBACEOICCBJKELGBJAB.jmiles at pop.net>
> > A divide by 8 conjugate regenerative divider has been built and tested
> > by NIST.
> > In principle it would be possible to generate F/2, F/4 and F/8 outputs
> > simultaneously by adding parallel conjugate filtered feedback paths
> > tuned to 3F/2, 7F/8, 3F/4, F/2, F/4 and F/8.
> > However the difficulties associated with optimising the phase shifts and
> > gains of all the filtered feedback paths may be more trouble than
> > its worth.
> Yes, I imagine I'll take the lazy way out and just run separate dividers in
> parallel from a 2- or 3-way splitter following the OCXO. Thanks for the
> uploads and links. Got some reading to do this weekend.
Each divisor would be really simple anyway.
> I rigged up a divider last night with a 220-MHz SAW filter and a
> randomly-chosen Mini-Circuits mixer, MMIC amp, and 2:1 splitter. I was
> surprised at how well it worked without any tweaking. It was kind of
> surreal to see the f/2 output appear abruptly once the 440-MHz input reached
> a certain level. At +4 dBm of excitation there was nothing at the output,
> but with +5 dBm at the input, a nice clean 220 MHz signal appeared out of
> nowhere at +16 dBm.
Did you experience the start of oscillation also as you went from +3 dBm to
+4 dBm? The impulse may be part of getting the oscillation running.
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