No subject

GPS does not disciplines the Rb.  The Rb unit is there
to take over in the even the GPS fails.  So that leads
me to believe that the XO is more accurate in the
short term as long as it has something to steer it
like a GPS or the Rb.  

So my guess is that the XO would really be a better
choice, but I am back to dividing the 15 MHz down to
10 MHz.  I understand about dividing by 3 and
multiplying by 2.  Could someone please provide a
circuit?

Am I right in my logic and am I going down the right
path with my project?

Thanks for all the expert support.  

Jamie






--- John Ackermann N8UR <jra at febo.com> wrote:

> Bruce Griffiths said the following on 01/19/2008
> 05:20 PM:
> > James R. Gorr wrote:
> >> I always assumed frequency references should be
> sine
> >> waves.  If that is not the case, I guess I can
> use
> >> this for a reference for other equipment?  And if
> a
> >> square wave is just fine, could I use a
> clock-block to
> >> divide the 15 MHz of the XO down to 10 MHz?  
> > If you ever have to do this, the clock block is an
> unnecessarily complex
> > solution.
> 
> Actually, the Clock-Block is about the worst
> possible solution to this
> problem (since I designed it, I don't have to worry
> about offending
> anyone in saying that!).
> 
> The synthesizer used in the Clock-Block has very,
> very bad phase noise;
> that's the price of very wide frequency coverage in
> a single chip.
> 
> I haven't done it to my unit yet, but from tracing
> the circuitry of the
> RFTG, it doesn't look like it would be hard to
> bypass the 10 to 15 MHz
> conversion circuitry and feed 10 MHz from the
> oscillator directly to the
> primary output.  That would be a much better
> solution.
> 
> John
> 
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