Re: Variation of secondary Q

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Jim,

At 08:22 PM 3/17/2002 -0800, you wrote:
>> Digital scopes have crystal controlled time bases.  200PPM Max error.
>Over what temperature range?? (Since you've mentioned freezing cold, etc..)
>I've found that most scope time bases, compared to something decent, to put
>it bluntly, are horrid..... If you are interested in measuring things
>accurately, you might contemplate a reference input of some sort..

The expensive stuff will stay indoors connected by cables.  200PPM was over
the rated operating temperature.  I assume Paul's data can tolerate of few
hundred PPM.  The data logging is by computer that is accurate to a few
seconds a day.  It could be sync to NST since it is connected to the web.

>
>Hmmmm.. Now, Terry, there is a huge transmitter of signals at convenient
>frequencies accurate to 1 part in 1E13 fairly close to you....
>One transmission is at 60 kHz, which might be useful....  You're close
>enough to get the ground wave, so ionospheric uncertainty shouldn't bite
>you...

WV (http://www.boulder.nist.gov/timefreq/stations/wwv.html) is about 5
miles away.  Its signals ride on every darn thing made of metal...  They
cut back power a few years ago which really helped the locals avoid the one
second clicks in their teeth...  These days, the signals cause little
interference.  I have frequency counters with Refute too at 10MHz if ones
wants to count em'.

>
>
>
>
>>
>> >Use a search coil eg
>> >ferrite rod for the field pickup and tune it to some convenient
>> >24hr long wave transmission so that a little of it appears in the
>> >scope trace along with the TC signal.
>
>Pick up the 60 kHz and mix it in... An FFT will make a dandy filter to
>separate things out...

I hope I have not missed something here.  I think everything is accurate
enough just as is.   Everything is crystal controlled and indoors.  Only
the coil, pickups, and line amps will be outside.  I'll have to run checks
to be sucre it is all stable.  Running one tonight ;-)

Cheers,

	Terry


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