-->...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 <[email protected]> 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: [email protected] [mailto:[email protected]] 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, [email protected] <[email protected]> wrote: > > > From: [email protected] <[email protected]> > > Subject: Re: [time-nuts] High end OCXO alternatives (or maybe an high > perf > Rb ?) > > To: [email protected] > > 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, > > [email protected] > > 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 > > > > > > > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
