[time-nuts] Morion MV89A position

Poul-Henning Kamp phk at phk.freebsd.dk
Wed Jan 29 15:54:05 UTC 2014


In message <20140129193210.W9lqik4I at smtp16.mail.yandex.net>, Charles Steinmetz 
writes:

>>Your aluminium box will very efficiently transport temperature 
>>changes from its full surface to your OCXO.
>
>I don't believe you understand how it works.  The air space in the 
>enclosure isolates the oscillator from the cast box.

Sorry, I had read it as you had the OCXO in close contact with the
box.

>>A plastic box with lid and filled with dry sand will do much better 
>>than your alubox.
>
>I experimented with dry sand and found that its thermal resistance 
>increased faster than its thermal capacitance.  By the time there was 
>sufficient capacitance there was way too much thermal resistance.

I'm not too fond of sand either, but I found it way better than air
for double-oven OCXOs.  Keeping the box air-tight (and sand-tight!)
is pretty important though.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.



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