[time-nuts] Thunderbolt mounting

Don Latham djl at montana.com
Sat Jul 14 00:54:00 UTC 2012


Don't bother with the concrete, just put the dirt back. You can even
just bury a vault with a lid under about 2 ft of dirt, will work just
fine.
Don

Chris Albertson
> I've got a foundation trench open right now.  I've been thinking it is a
> great opportunity to keep some electronics at a very stable temperature.
>  What's better then tossing it in a big hole in the ground then dumping
> a
> truckload of concrete on top?   Likely the only thing I'll burry is a $2
> temperature sensor.  In So. California you don't need to go very deep to
> reach stable temp.
>
>
>
>
> On Fri, Jul 13, 2012 at 5:25 PM, Neville Michie <namichie at gmail.com>
> wrote:
>
>>
>> You have to go deep into the ground to get stability.
>> At 15 metres deep there is a lovely pure sine wave of about 0.3C P-P.
>> I measured it on the roof of a cave, its period one year.
>> My design for the bolt is to put it in a 1/4 inch thick aluminium box
>> which
>> is held at a constant temperature by a fan. Switching control is good
>> enough as the
>> thermal diffusivity of 1/4 inch aluminium will attenuate any spectral
>> components shorter than
>> a minute. The aluminium box is so conductive that the box is
>> isothermal,
>> so once the bolt
>> has established its internal temperature gradients, nothing changes.
>> cheers,
>> Neville Michie
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>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
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-- 
"Neither the voice of authority nor the weight of reason and argument
are as significant as experiment, for thence comes quiet to the mind."
R. Bacon
"If you don't know what it is, don't poke it."
Ghost in the Shell


Dr. Don Latham AJ7LL
Six Mile Systems LLP
17850 Six Mile Road
POB 134
Huson, MT, 59846
VOX 406-626-4304
www.lightningforensics.com
www.sixmilesystems.com





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