Re: [time-nuts] What cut do I have?

2013-01-29 Thread M. Simon
Those 32KHz watch crystals are very flat in the vicinity of the turnover. They don't age well. But if all you need is temperature stability and you can correct for aging a nice little electric heat pump (heats and cools) to keep the crystals at around the 25C inflection point might be

Re: [time-nuts] What cut do I have?

2013-01-29 Thread Bob Camp
Hi Any crystal in the vicinity of turnover point is going to be pretty flat. That relates directly to the way turnover is defined. There are some exceptions (10811), but the vast majority of OCXO designs operate the crystal very near the turnover point. The whole chill it down approach was

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Bernd Neubig
-Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Bob Camp Gesendet: Montag, 28. Januar 2013 03:39 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] What cut do I have? Hi It could also be an AT, IT or FC

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Bob Camp
: Monday, January 28, 2013 11:48 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] What cut do I have? Hi, IT and FC cut crystals are not very often used in OCXO. But if, then the lower turn point is used (below the inflection temperature), which means that the cold

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Bernd Neubig
Auftrag von Bob Camp Gesendet: Montag, 28. Januar 2013 18:40 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] What cut do I have? Hi The only time I've seen them used in OCXO's both the FC and IT were run on the upper turn (just like an AT). Thus the frequency goes

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Magnus Danielson
- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Bob Camp Gesendet: Montag, 28. Januar 2013 18:40 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] What cut do I have? Hi The only time I've seen them used in OCXO's both the FC

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Bob Camp
] On Behalf Of Bernd Neubig Sent: Monday, January 28, 2013 11:48 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] What cut do I have? Hi, IT and FC cut crystals are not very often used in OCXO. But if, then the lower turn point is used (below the inflection

Re: [time-nuts] What cut do I have?

2013-01-28 Thread Bob Camp
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Bob Camp Gesendet: Montag, 28. Januar 2013 18:40 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] What cut do I have? Hi The only time I've seen them used in OCXO's both the FC and IT were run on the upper turn

Re: [time-nuts] What cut do I have?

2013-01-27 Thread Ed Breya
If you meant to say the frequency starts out too high when the oven is cold, then I think it's AT cut. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the

Re: [time-nuts] What cut do I have?

2013-01-27 Thread Magnus Danielson
On 01/28/2013 01:01 AM, Ed Breya wrote: If you meant to say the frequency starts out too high when the oven is cold, then I think it's AT cut. OK. I looked at the previous posts and it was not very clear from them, and I was too lazy/busy to heat up an idel AT OCXO. I just felt the +41.4 ppm

Re: [time-nuts] What cut do I have?

2013-01-27 Thread Bob Camp
Hi It could also be an AT, IT or FC cut. A lot depends on just how hot the oven is running. Best bet is indeed AT. Bob On Jan 27, 2013, at 7:40 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 01/28/2013 01:01 AM, Ed Breya wrote: If you meant to say the frequency starts out too