[time-nuts] What sort of oscillator is this?
tmiller11147 at verizon.net
Sun Sep 28 14:37:29 EDT 2014
Looks like I am having crow for lunch today. I did find the 1D5
installation instructions and at first it looked like the standard OCXO
package used in many HP instruments. But some closer reading shows that it
may in fact be a 50 MHz TCXO.
----- Original Message -----
From: "Dr. David Kirkby (Kirkby Microwave Ltd)"
<drkirkby at kirkbymicrowave.co.uk>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Sunday, September 28, 2014 4:57 AM
Subject: Re: [time-nuts] What sort of oscillator is this?
> On 28 Sep 2014 03:11, "Alexander Pummer" <alexpcs at ieee.org> wrote:
>> that is most likelly a TXCO, what is in the user's manual about warm up
> Two people responded - one says a OCXO and the other an TCXO!!
> The warmup time is I think an hour, but clearly that is not the time for
> an oven to warm up.
> If it was a frequency counter then I think the warmup time would be just
> that of the oscillator, as really I can't see much other than the
> oscillator needing to be stable. But on a VNA one needs the temperature of
> cables to be stable, as expansion of cables is likely to cause phase
> instability. So the time for the cables lengths to stabilise is probably
> much longer than it would take an oven to stabilise.
>> if they have a special precise reference -- like for spectrum analyzer or
> frequency counter that would have at least one magnitude better stability
> I find it odd that an instrument that probably cost $50,000 when new did
> not have a TCXO as standard, and perhaps an oven as an option.
> But I think HP did this sort of thing a lot. Something that would have
> very little to add, became an expensive option. In some cases these
> expensive options are nothing more than enabling a bit of software,
> although the R&D cost of the software is probably a lot more than the
> hardware cost of adding a better oscillator.
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