[time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

Donald E. Pauly trojancowboy at gmail.com
Fri Jun 2 19:40:58 UTC 2017


That is not true.  I say that thermal coolers have made ovens obsolete.  A
zero temperature coefficient at room temperature is easier to hit than a
zero temperature at the upper turnover point when such a thing exists.  See
curve 0 in Figure 6 at https://coloradocrystal.com/applications/ .

πθ°μΩω±√·Γ
WB0KVV


On Friday, June 2, 2017, Bob kb8tq <kb8tq at n1k.org
<javascript:_e(%7B%7D,'cvml','kb8tq at n1k.org');>> wrote:

> Hi
>
> 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.
>
> Bob
>
> 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> wrote:
>
>> Hi
>>
>> 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.
>>
>> Bob
>>
>>
>



More information about the Time-nuts_lists.febo.com mailing list