[time-nuts] Ocxo wrong frequency.

Bob Camp kb8tq at n1k.org
Sun Jun 19 17:54:42 EDT 2016


What you have is an SC cut OCXO that has an incorrectly tuned trap circuit in it (or 
a defective crystal). Of the two I’d bet on the trap. It’s firing up on the wrong mode and
staying there. It switches back and forth due to interaction between the limiter stage
and the trap circuit. Ideally there should not be any interaction ….obviously not true 
in this case.


> On Jun 19, 2016, at 4:51 PM, Iwa2008 via time-nuts <time-nuts at febo.com> wrote:
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> Has anyone come across oscillators outputting the incorrect frequency when powered up. The frequency that is outputted reads 10.8 Mhz, and falls a few HZ as the ocxo warms up. The frequency is stable, even when measured over the course of many hours.  It is a repeatable issue, when the ocxo's are powered from 2 particular power supplies. Yet when powered on again, they give the correct frequency. The affected ocxo's are c-mac units, both nos/"ebay" used.</div><div id="AOLMsgPart_2_bea72c74-0991-404a-ad92-fdbd77734860">
> </div><div id="AOLMsgPart_2_bea72c74-0991-404a-ad92-fdbd77734860">Thanks, </div><div id="AOLMsgPart_2_bea72c74-0991-404a-ad92-fdbd77734860">Brendan</div><div id="AOLMsgPart_2_bea72c74-0991-404a-ad92-fdbd77734860">
> Sent from AOL Mobile Mail
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> </div>
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