[time-nuts] Making a 10811 better

Don Latham djl at montana.com
Tue Sep 20 19:52:01 UTC 2011


Could very well have been SF6...
Don

J. Forster
> Likely one of the Freons (TM) or Sulphur Hexafluoride.
>
> Tektronix used a Freon in their 40 KV High Voltage probes. The Vapor
> pressure of some of those compounds is low at 70F, but they do have to
> be
> sealed.
>
> Unfortunately, virtually all Freon useage has been banned by the EPA
> (they
> are said to be "greenhouse gases") and the stuff in now almost
> unobtanium.
>
> -John
>
> ===============
>
>
>> Long ago and far away, I recall a friend using a gas that had its
>> liquid/gaseous transition near room temperature and was inert (not an
>> inert gas) to pressurize a vessel having high impedance circuits in
>> it.
>> I'm darned if I can remember what it was. Available in so-called "lab
>> bottles" ie not monster cylinders.
>> Would have to be sealed, though.
>> Don
>>
>> Tijd Dingen
>>> Yeah, I was wondering about that. There's a reason they use helium to
>>> search for leaks on vacuum chambers. Those pesky small atoms go
>>> everywhere...
>>>
>>>
>>>
>>> ________________________________
>>> From: J. Forster <jfor at quikus.com>
>>> To: Discussion of precise time and frequency measurement
>>> <time-nuts at febo.com>@qkmail9.01trend.com
>>> Sent: Tuesday, September 20, 2011 9:00 PM
>>> Subject: Re: [time-nuts] Making a 10811 better
>>>
>>> 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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ------------------------------
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list
>>>>> time-nuts at febo.com
>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>>>
>>>>> End of time-nuts Digest, Vol 86, Issue 55
>>>>> *****************************************
>>>>
>>>>
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>>>
>>>
>>>
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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
>>
>>
>>
>> _______________________________________________
>> 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.
>>
>>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
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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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