Re: [Discuss-gnuradio] external clock

[Bdale Garbee]

On Fri, 2005-08-19 at 08:52 -0400, John Ackermann N8UR wrote:
> Reflock II that allows you to
> lock just about any oscillator to a standard frequency, or to a 1pps
> signal.

I'm aware of the Reflock designs, and in fact have some of VE1ALQ's
boards in hand (bare boards only).

> I'm going to use one to generate 64MHz locked to my house
> standard -- haven't yet figured out just what the best choice of VCXO
> will be, though.

Aye, that's the rub.  Bob's point about phase noise in the on-chip PLL
being a potential source of problem is a good one.  Without digging in
to that, it suggests to me that this might be a better approach and thus
a suitable choice of VCXO is the problem we really need to address.

Meanwhile, I poked Matt for an updated delivery estimate on the USRP L
and S band daughter cards the other day but haven't heard back from him
yet.  Does anyone else (Eric?) know enough about the design of those to
share the up/down conversion approach?  Is there another oscillator to
tame, a PLL driven by a USRP reference clock, or what?  

There's only two months until the first half of the ARRL EME contest,
which I'd love to be on the air for on 1296...

Bdale