[time-nuts] Thermal insulation choice?
Mark Spencer
mspencer12345 at yahoo.ca
Sat Jan 7 00:01:19 UTC 2012
As an additional data point..
When experimenting with various forms of insulation for a thunderbolt board I found that a corrugated carboard box provided a noticeable decrease in temperature fluctuations while limiting the overall temperature rise. Even small ammounts of additional insulation (ie. a few layers of thin flexible foam sheets maybe 2 mm thick used for wraping items for shipment) caused the temperature as reported by the thunderbolt to increase signficantly. (Maybe 15 Deg C IIRC ?)
--- On Fri, 1/6/12, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
> From: Magnus Danielson <magnus at rubidium.dyndns.org>
> Subject: Re: [time-nuts] Thermal insulation choice?
> To: time-nuts at febo.com
> Received: Friday, January 6, 2012, 6:10 PM
> Rick,
>
> On 01/06/2012 10:14 PM, Rick Karlquist wrote:
> > John Ackermann N8UR wrote:
> >> I am looking for a readily available (from Home
> Depot or other local
> >> source) insulating material to use in a chassis
> that's housing a
> >> sensitive OCXO. My goal is just to slow down
> any external thermal
> >> transients so the oven loop has time to react
> gracefully.
> >
> > Before making this into a science project, consider
> this data
> > point: We converted the oscillator in a 10811 to
> run in mode
> > B at 10.95 MHz. The tempco in mode B is about 30
> ppm per degree
> > C. Needless to say, the converted 10811 was
> extremely sensitive
> > to crystal temperature. I could wave my hands
> around it and notice
> > the temperature change from the air currents.
> However, simply
> > putting the 10811 into a small empty cardboard box
> completely
> > solved this problem. No rocket science
> necessary. So in the
> > short term, this simple box was like a double
> oven. Of course,
> > in the long run, the 10811 thermal gain is only 1000
> or so and
> > you can see the effect of the HVAC shutting down at
> 7PM, etc.
>
> This is essentially what I've found quite useful at many
> times, quick air fluctuations affects crystals pretty good
> but just blocking the air helps to slow down things.
> Long-term creeps through but is not on the same scale.
>
> A large enough cardboard box will leak over-temperature
> such that the oven keeps working.
>
> Cheers,
> Magnus
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
More information about the time-nuts
mailing list