[time-nuts] Making a 10811 better

J. Forster jfor at quikus.com
Tue Sep 20 19:00:31 UTC 2011


Helium in contact with Dewar walls is a very bad idea. He diffuses through
many glasses and will completely destroy the vacuum in a Dewar in hours.

-John

=================


> Depends what you mean by "much higher". Helium has almost 6 times higher
> thermal conductivity. Hydrogen is higher, but has certain drawbacks. ;-)
>
> regards,
> Fred
>
>
>
> ________________________________
> From: Dick Moore <richiem at hughes.net>
> To: time-nuts at febo.com
> Sent: Tuesday, September 20, 2011 8:39 PM
> Subject: Re: [time-nuts] Making a 10811 better
>
> Is there a relatively inert gas that has much higher thermal conductivity
> than air? Then a flask makes sense and is not the size of the basement...
>
> Dick Moore
>
>
> On Sep 20, 2011, at 5:00 AM, time-nuts-request at febo.com wrote:
>
>> ------------------------------
>>
>> Message: 2
>> Date: Mon, 19 Sep 2011 18:21:30 -0700
>> From: ed breya <eb at telight.com>
>> To: time-nuts at febo.com
>> Subject: [time-nuts]  Making a HP 10811 better
>> Message-ID: <201109200121.p8K1LgsE015776 at mail30c40.carrierzone.com>
>> Content-Type: text/plain; charset="us-ascii"; format=flowed
>>
>> One last thing regarding oil-filling. My previous comment was made
>> picturing oil inside the oscillator block only - not outside, or
>> between the outer parts - if there is a resistance wire heater (I
>> think it's heated with Qs only on the 10811) it is held together with
>> various tapes and adhesives that could soften or dissolve. Also, the
>> insulation would not insulate very well of saturated with oil, and
>> could possibly soften or break down somehow. I would not recommend
>> dunking the whole thing in a vat of oil.
>>
>> And one final, final note: If oil is somehow effectively contained in
>> the oscillator block, then a void (bubble) of some sort, or an
>> expansion facility or vent would be needed to relieve the pressure
>> changes during warmup.  Otherwise, when started up, the expanding oil
>> would have to either leak out, or deform (or damage) something. This
>> would be equivalent to dramatically increasing barometric pressure,
>> and certainly effect the oscillator frequency.
>>
>> Ed
>>
>>
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Mon, 19 Sep 2011 23:20:28 -0600 (MDT)
>> From: "Don Latham" <djl at montana.com>
>> To: "Discussion of precise time and frequency measurement"
>>     <time-nuts at febo.com>
>> Subject: Re: [time-nuts] Making a HP 10811 better
>> Message-ID:
>>     <d850d565aabe9422dd4172b9c904d5d4.squirrel at webmail.montana.com>
>> Content-Type: text/plain;charset=iso-8859-1
>>
>> Ah well. Just a thought. I was thinking of simply dumping the whole
>> thing into a picnic jug full of baby oil :-)
>> Sorta scatterbrained, but I have seen mentioned on the list a basement
>> sized steel block ...
>> Don
>>
>> ed breya
>>> One last thing regarding oil-filling. My previous comment was made
>>> picturing oil inside the oscillator block only - not outside, or
>>> between the outer parts - if there is a resistance wire heater (I
>>> think it's heated with Qs only on the 10811) it is held together with
>>> various tapes and adhesives that could soften or dissolve. Also, the
>>> insulation would not insulate very well of saturated with oil, and
>>> could possibly soften or break down somehow. I would not recommend
>>> dunking the whole thing in a vat of oil.
>>>
>>> And one final, final note: If oil is somehow effectively contained in
>>> the oscillator block, then a void (bubble) of some sort, or an
>>> expansion facility or vent would be needed to relieve the pressure
>>> changes during warmup.  Otherwise, when started up, the expanding oil
>>> would have to either leak out, or deform (or damage) something. This
>>> would be equivalent to dramatically increasing barometric pressure,
>>> and certainly effect the oscillator frequency.
>>>
>>> Ed
>>>
>>>
>>> _______________________________________________
>>> 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.
>>>
>>
>>
>> --
>> "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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>>
>> End of time-nuts Digest, Vol 86, Issue 55
>> *****************************************
>
>
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