[time-nuts] Vremya-ch Hydrogen Masers
Bob Camp
lists at rtty.us
Wed Mar 3 00:47:47 UTC 2010
Hi
The dielectric constant of water is also highly temperature dependent. If it's a direct dielectric thing, it should show up as a secondary temperature effect.
Bob
On Mar 2, 2010, at 6:30 PM, Joseph M Gwinn wrote:
> time-nuts-bounces at febo.com wrote on 03/02/2010 04:51:15 PM:
>
>> From:
>>
>> "Bob Camp" <lists at rtty.us>
>>
>> To:
>>
>> "'Discussion of precise time and frequency measurement'" <time-
>> nuts at febo.com>
>>
>> Date:
>>
>> 03/02/2010 04:55 PM
>>
>> Subject:
>>
>> Re: [time-nuts] Vremya-ch Hydrogen Masers
>>
>> Sent by:
>>
>> time-nuts-bounces at febo.com
>>
>> Hi
>>
>> Without doing a lot of digging, I doubt we'll find out just what they
> did
>> (or didn't) find and fix. They certainly started with a "from scratch"
>> design. They may have multiple points of departure from the US approach.
>>
>> Then again, it may just be a better brand of coating they spray on the
>> boards.
>
> It does not take much moisture absorption in printed circuit boards and
> conformal coats to cause significant variation in electrical delay with
> variation in humidity, given that the dielectric constant of water is
> about 80. The solution may be no more complex than use of only
> low-absorption materials surrounded by hermetic metal enclosures also
> containing a cloth bag of moisture absorbing chemical granules.
>
> Joe
>
>
>> Bob
>>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
>> Behalf Of Magnus Danielson
>> Sent: Tuesday, March 02, 2010 3:05 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Vremya-ch Hydrogen Masers
>>
>> Bob Camp wrote:
>>> Hi
>>>
>>> I hear that the US ones look better than the Russian ones when you
> have
>> them
>>> spinning around on a frozen pond. Nether one does a very good
>> triple axle
>>> jump though. At least that's what I read on the internet....
>>>
>>> ---------------
>>>
>>> There's always been a *lot* of debate about exactly what the source of
>>> humidity impact on the US built masers is. It's been talked
>> about for at
>>> least 30 years. It's not real surprising if somebody
>> somewhere has found
>> the
>>> answer and fixed it.
>>
>> Rather, what did the Russians figure out and fixed?
>>
>> 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.
>>
>>
>>
>>
>> _______________________________________________
>> 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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
More information about the Time-nuts_lists.febo.com
mailing list