[time-nuts] Locking gunn diode

[John Miles]

I agree that injection locking may not be ideal, but mainly because it's not
that hard to do the job with an actual PLL.  Here's an example of a
quick-and-dirty Gunnplexer hack with an Analog Devices PLL chip and a
Hittite prescaler: http://www.ke5fx.com/gunnpll.html .  Close-in spectral
purity was not great, but it would be fine for NBFM work.

-- john, KE5FX

> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Didier Juges
>
> If you are talking about injection locking, that will probably not be
> practical. The Gunn is not stable enough (not the Gunn itself, but the
> cavity where it will be installed) to stay close enough to the right
> harmonic to stay locked, and the high order difference between the gunn
> and the injection signal makes it just about impossible. Even if you
> could lock it, you probably would have 10 MHz spurs (I am just guessing).
>
> Phase locking through a PLL system is possible of course, even though it
> will be relatively complicated, unless you find one of these synthesizer
> boards on eBay, designed for YIG oscillators, and modify it to drive a
> varactor.
>