[time-nuts] Is this DOCXO an SC or AT cut rock?

Garry Thorp GThorp at pascall.co.uk
Mon Aug 11 08:25:57 EDT 2014


Scott,

It doesn't look like AT-cut. AT-cut oven crystals are run at their upper turnover point, which is a minimum, so the frequency starts high from power up at normal room temperature.
With SC-cut, the f/T curve is shifted to the right and they are operated at their lower turnover point (a maximum), so the frequency starts off low.

Regards,
Garry


On 08/10/2014 08:54 AM, Scott Newell wrote:

I'm curious if an OCXO has an SC or AT cut crystal in it. There's no

EFC, so I can't measure sensitivity. I did measure the frequency

change from cold startup, thinking that an SC cut would stabilize

quicker than an AT. I don't have a good AT OCXO to compare against,

but I do have a Morion MV89A (should be an SC, right?).

Graphs:

http://n5tnl.com/time/mv89a/mv89a.png

http://n5tnl.com/time/mv89a/unknown.png






More information about the time-nuts mailing list