[time-nuts] High end OCXO alternatives (or maybe an high perfRb ?)

Azelio Boriani azelio.boriani at screen.it
Thu Dec 8 13:46:26 EST 2011


-->...Sell the "junk"...<-- I wouldn't consider junk something that has
taken part to a test for 10E-13... anyway I think it'll be expensive that
kind of test.

On Thu, Dec 8, 2011 at 5:57 PM, Bob Camp <lists at rtty.us> wrote:

> Hi
>
> A device that's known to be at a legitimate < 5x10^-13 at 100 seconds, will
> cost you some money. That's true what ever it is. If it's an OCXO it's also
> likely that it will perform at that level at 1 and 10 seconds. An Rb likely
> will degrade a bit at the shorter Tau's. An OCXO's stability should degrade
> at the longer Tau's, the Rb's should get better out to at least 10,000
> seconds.
>
> You can indeed get lucky and find the one in a hundred part. Often this is
> done by getting a hundred parts, and then powering them up for a couple of
> months. Test them all for short term and keep the best. Sell the "junk" and
> move on..
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Mark Spencer
> Sent: Thursday, December 08, 2011 10:28 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] High end OCXO alternatives (or maybe an high
> perfRb
> ?)
>
> Bert, that is a good question and thanks for your feedback.
>
> At this point the answer is it depends (:  (On availability, price etc..)
>
> To add a bit more context to this matter, I believe I'm somewhat limited by
> my measurement systems at Tau's of significantly less than 100 seconds or
> so
> (I've got two 5370B's and a Tek 2252 scope that can work as Time interval
> counter and feed data into time lab, each instrument has it's pros and cons
> but I don't have a lot of confidence in my measurements at Tau's of less
> than 100 seconds where as measurements at 100 seconds and greater a
> repeatable between different instruments etc..)
>
> In the long run I'll probably look at getting equipment to measure shorter
> tau's and phase noise but that's another project for another year or more
> likely another decade, but getting an OCXO  now that would be usefull later
> on makes some sense as well.
>
> If I had to put a stick in the ground I'd likely settle for 5E-13 or less
> at
> a tau of 100 seconds.   I'm not that worried about performance at shorter
> tau's at this time.   I realize that OCXO's typically exceed their specs if
> left running in a stable environment (as I suspect my FTS 1050 is doing.)
>
> Thanks for the comments about the HP 5065.
>
> Regards
> Mark
>
>
>
>
> --- On Thu, 12/8/11, EWKehren at aol.com <EWKehren at aol.com> wrote:
>
> > From: EWKehren at aol.com <EWKehren at aol.com>
> > Subject: Re: [time-nuts] High end OCXO alternatives (or maybe an high
> perf
> Rb ?)
> > To: time-nuts at febo.com
> > Received: Thursday, December 8, 2011, 10:00 AM
> > Mark
> > 10E-13 at 100 sec is  a wide range. What about at 1
> > and 10 sec. and  are
> > you talking about 3, 5, 9 E-13.
> > I personally have quite a few 10811's that brake the 1E-12
> > from 1 to 100
> > seconds my best OCXO is a Datum 1000 that is 3.5E-13 at 1
> > sec.  and 4 at 10
> > and 7 at 100 sec. I control it with a FRK-H which has 7E-13
> > at 100 sec.
> > In this range short of a $ 15 000 Oscilloquartz the best is
> > a HP 5065. They
> >  all are below 1 E-12  some as low as 1E-13 at 100
> > sec. but the only  way I
> > know how you know what you are getting is work with Corby
> > Dawson.
> > Bert Kehren
> >
> >
> > In a message dated 12/7/2011 9:41:56 P.M. Eastern Standard
> > Time,
> > mspencer12345 at yahoo.ca
> > writes:
> >
> > Greetings:
> >
> > I'm contemplating starting a search on the  "typical
> > auction sites" for a
> > high end OCXO (or possibly a high end Rb) that  would
> > be suitable for
> > characterizing the performance of an FTS
> > 1050.   From time to time I've seen ADEV
> > figures of in the 10E-13  range (at a typical Tau of
> > 100 seconds) when
> > comparing the FTS 1050 in  question to one of my
> > GPSDO's and one of my Rb's.
> >
> > At this  point I'm contemplating looking for:
> >
> > Another FTS 1050
> > Various Datum  / FTS stand alone OCXO's
> > An Oscilloquartz BVA OCXO
> > A Sulzer  OCXO
> > Maybe an HP 5065
> >
> > (I've already assembled a modest collection of  half a
> > dozen various
> > 10811's and don't really want to buy any more at this
> > point.)
> >
> > Essentially I'm looking for something with a reasonable
> > likely  hood of
> > consistently having an ADEV in the 13's at Taus of 100
> > seconds or  so.
> > I'm thinking that another FTS 1050 is probably the
> > most  likely alternative
> > but I'm trying to keep an open mind to other
> > options.   I'm not really
> > interested in a Cesium standard but if anyone has any
> > other  suggestions of
> > products I could look for (other than a H maser
> > (:   )  comments on or off list
> > would be appreciated.
> >
> >
> > Regards Mark  Spencer
> >
> >
> >
> >
> >
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