[time-nuts] Making the most of SRS Rb source
cfmd at bredband.net
Thu Jan 19 20:05:17 EST 2006
From: Mike Nolan <nolan at naic.edu>
Subject: Re: [time-nuts] Making the most of SRS Rb source
Date: Wed, 18 Jan 2006 21:58:00 -0400
Message-ID: <20060119015800.GB8922 at mofongo.naic.edu>
Now, considering that I would like to probe a pulsar what would be the typical
gear needed? At what frequency do I probe? Just out of curiosity, I don't
intend to overtrash my VISA card for that purpose, so you can be calm about
PS. I should not have bought the GPS clock from that german fellow Heisenberg
and put the antenna on my house, because either I know where it is but not when
or I don't know when it is but where. :P
> You should definately ask the VLBI people how to deal with the maser.
> You definately don't want to touch the frequency reference during an
> observation. They really do need the 10^-15 short-term stability. They
> can solve for pretty substantial frequency offsets (and linear drifts)
> after the fact, but phase noise will kill the experiment.
> If you want a GPS-disciplined Rb, you'd probably be better off buying
> one than fiddling with yours if it's really running the telescope.
> But I suspect you can do better yourself with practice. Is this the 12m?
> When we got our maser, we did about what you suggest: futz with it
> for a month and get it stabilized, then leave it alone as much as you
> can. We reset the time if it gets off by 250 ns, and the frequency occasionally.
> Mostly, log what you do, or the pulsar timing people will have a
> fit. You may not get much pulsar timing at 100 GHz, but the pulsar folk
> have their hands in all pies.
> Sorry if this information is redundant, but and experiment that's blown
> becaus of a bad frequency reference is a bummer.
> Mike Nolan +1 787 878 2612x334 Fax: +1 787 878 1861 nolan at naic.edu
> Arecibo Observatory, HC 3 Box 53995, Arecibo, Puerto Rico 00612 USA
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> time-nuts at febo.com
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