Berndt I believe you are describing a "Triax" connector I found them through Trompeter but I believe they are sold by Farnell and RS Components in the UK. The same connector was used I think on some of the HP system digital voltmeters. Cheers de Alan G3NYK
----- Original Message ----- From: "Bernd T-Online" <[EMAIL PROTECTED]> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Sunday, December 09, 2007 2:21 PM Subject: Re: [time-nuts] Super stable BVA Quartz resonators... BVA?? > Tim Shoppa wrote: > > For a while, didn't HP sell temperature probes which were in fact > > quartz crystals? Oscillation frequency was converted by some simple > > electronics to a temperature, and at the time (60's?) they were > > exquisitely convenient for measuring way better than a tenth of a > > degree. > > Either the frequency drift was negligible or it > > was so slow that I don't remember any manual removal of frequency > > drift effects. > > I'm guessing the probe crystals were some special cut (don't know which!) > > which was fairly linear or at least monotonic over the measurement > > temperatures. I'm guessing that HP chose a cut which had a very large > > tempco such that tempco dominated over any frequency drift. > > They did indeed. This was the HP2801A, later followed by the HP2804A. > It uses a so-called LC-cut (Linear Coefficient) quartz crystal sensor, > which is a doubly rotated cut with ultra-linear frequency vs. > temperature characteristic with a slope of 35.4 ppm/K. > > For more information see http://hparchive.com/Journals/HPJ-1965-03.pdf > > BTW: I proudly own a HP2801A plus two crystal sensor elements. However I > cannot connect them to the instrument, because the 2801A has a special > connector for it. It looks like a smaller version of a BNC connector, > but the bayonet has three "nipples" instead of two. Does anyone on the > list know what kind of connector that is and where to get the > counterpart (plug)? > > Regards > > Bernd > DK1AG > > _______________________________________________ > time-nuts mailing list -- time-nuts@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.