[time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies
kb8tq at n1k.org
Fri Jun 2 15:22:24 EDT 2017
Any real crystal you buy will have a tolerance on the angle. In the case of a crystal cut for turn
the temperature will be a bit different and you will match your oven to it. If you attempt a zero
angle cut, you will never really hit it and there is no way to compensate for the problem.
> On Jun 2, 2017, at 3:19 PM, Donald E. Pauly <trojancowboy at gmail.com> wrote:
> A cut at that angle has no turn over temperature. The zero temperature coefficient point is 25°. Its temperature coefficient everywhere else is positive.
> On Friday, June 2, 2017, Bob kb8tq <kb8tq at n1k.org <mailto:kb8tq at n1k.org>> wrote:
> If you are going to use an oven, it’s better to run it at the turn temperature of
> the crystal. That would put you above 50C for an AT and a bit higher still for an SC.
> > https://www.febo.com/pipermail/time-nuts/2017-May/105566.html <https://www.febo.com/pipermail/time-nuts/2017-May/105566.html>
> > If we build this circuit it would be a bench model not designed to be
> > inside a hot chassis. It would be able to lock ± 5° C of 25° C. My
> > idea of an oven is to keep the crystal and oscillator at 25° C ±0.001
> > °C with 60 second warm up/cool down time.
> > πθ°μΩω±√·Γλ
> > WB0KVV
> > ---------- Forwarded message ----------
> > Date: Fri, Jun 2, 2017 at 5:57 AM
> > Subject: Re: [time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies
> > Hi
> > I would suggest you check a few real crystals over the 20 to 40C range ….
> > With all the “stuff” in a 5061, it will change (rise) at least 10C
> > after turn on.
> > Bob
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