I just heated up with a soldering iron and pulled out the pins of a standard DB25 connector that would get in the way. No problem, lovely budgie.
David N1HAC ________________________________ From: time-nuts <time-nuts-boun...@febo.com> on behalf of Bruce Griffiths <bruce.griffi...@xtra.co.nz> Sent: Saturday, April 15, 2017 11:11 PM To: Discussion of precise time and frequency measurement; Larry McDavid Subject: Re: [time-nuts] HP E1938 More precisely the active EFC range is +1.25 to +3.75V with an absolute minimum of 0V and an absolute max of +5V. At least this is the range that the pseudo differential AD7714 ADC inputs monitoring the EFC are configured for. Bruce > On 16 April 2017 at 14:57 Bruce Griffiths <bruce.griffi...@xtra.co.nz> wrote: > > > 0 to +5V dc max, however only the 0 to 2.5V range appears measurable by > the AD7714 ADC on the PCB. > > Increasing the EFC voltage decreases the capacitance in series with the > crystal requiring an increase in the inductance exhibited by the crystal > hence requiring a lower oscillator frequency. > > Bruce > > > > > > On 16 April 2017 at 13:01 Larry McDavid <lmcda...@lmceng.com> wrote: > > > > The units now available on eBay have various types of D-Subminiature > > connectors and can be on either side of the board. I will have to > > wait > > until my unit arrives to see what I get. It should be possible, if > > necessary, to remove the connector and replace it with a more > > convenient > > D-Submin connector on the desired side of the board. > > > > I did not originally note the additional zip'd info available from > > that > > eBay website but now have those files. Thanks for that link. > > > > So far, I have not seen any spec for the EFC voltage and polarities > > used > > in the "Integrated PWB." Anyone know that? > > > > The "full instrument" version also available now on eBay is a > > complete > > GPSDO but at $130 plus $80 shipping. I really don't need yet another > > GPSDO but would use the integrated PWB assembly for a low ADEV > > free-running 10 MHz source. I have a HP 10811D for that now but will > > evaluate this new unit for performance. > > > > Anyone have experience doing this and know the EFC requirements? > > > > Larry > > > > On 4/15/2017 4:01 PM, Richard (Rick) Karlquist wrote: > > > > > > > > > > It's been 20 years, but I will try to recap what I remember > > > about this connector. I believe there were 3 customers, > > > and one of them required the DB connector with coax inserts > > > for reasons of backward compatibility. I think this > > > vendor was Motorola. We did not actually use the coax > > > inserts, but left them blank and ran the RF, etc on > > > ordinary pins. I believe you can make an ordinary male > > > DB-25 mate with these insert versions by clipping off some > > > of the pins that would be blocked by the female insert > > > version. I vaguely remember that the other 2 vendors > > > used gender changers or something. There might have > > > an issue with the mating plane location being different > > > for different customers. > > > > > > I am sure that time-nuts, being talented at repurposing, > > > will be able to think about this problem and come up with > > > a simple solution to interfacing with these boards. > > > No need to buy insert type connectors. I never had > > > any trouble making cables that connected to these units > > > using plain vanilla DB25's. > > > > > > Rick N6RK > > > > > > On 4/15/2017 10:42 AM, Larry McDavid wrote: > > > > > > > > > > > > > > Ok, so a standard DB 25-pin socket-contact connector > > > > will mate with the > > > > on-board connector with the center hole and missing > > > > pins. That's good! > > > > > > > > I now notice a comment on your webpages about this > > > > device in which you > > > > mention a schematic. Do you have a schematic of this > > > > board? If so, can > > > > you point to it or send me a copy. > > > > > > > > I was unaware of the complete packaged unit on eBay; > > > > thanks for that. > > > > > > > > Another poster mentioned the wiring of the connector on > > > > the full > > > > instrument version power connector; is that pin-out and > > > > spec available? > > > > > > > > Larry > > > > > > > > On 4/15/2017 5:05 AM, Tom Van Baak wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I purchased one of these HP E1938 OCXO > > > > > > recently on eBay but have not > > > > > > yet > > > > > > received it. > > > > > > > > > > > > Is that special D-Submin connector a > > > > > > receptacle-shell, pin contact > > > > > > version? Will a standard plug-shell, socket > > > > > > contact 25-pin D-Submin > > > > > > fit it? > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > I'll cc the group here since we may get some > > > > > useful comments. > > > > > > > > > > I'm not exactly sure what you mean. The E1938A > > > > > oscillators that I've > > > > > seen and tested look like this: > > > > > > > > > > http://www.leapsecond.com/museum/e1938a/ [http://www.leapsecond.com/museum/e1938a/E1938A.jpg]<http://www.leapsecond.com/museum/e1938a/> HP E1938A Quartz Oscillator - LeapSecond<http://www.leapsecond.com/museum/e1938a/> www.leapsecond.com 20-Sep-2003. Introduction. The HP E1938A is a very modern ovenized SC-cut quartz oscillator of radical design that had little or no product release due to project ... > > > > > > > > > > And those can be interfaced with a simple D-sub > > > > > DB25 connector on the > > > > > PCB. For connections, see that page, or any > > > > > number of postings about > > > > > the E1938 in the time-nuts archives. > > > > > > > > > > Note that on eBay there are at least three > > > > > variations of E1938A > > > > > oscillator. The item#'s below are just random > > > > > search picks (I have no > > > > > affiliation with any buyers or sellers) and I > > > > > also know not all > > > > > surplus refurbished surplus recycled surplus > > > > > stuff works. But we do > > > > > this because when they did work, they are > > > > > sometimes totally amazing. > > > > > > > > > > 1) There's the bare "puck" alone, as in > > > > > http://www.ebay.com/itm/290829077542 -- and I > > > > > have no idea where one [http://thumbs1.ebaystatic.com/d/l225/m/m7VhJ-Dcf11Lgm5KeQf3CnQ.jpg]<http://www.ebay.com/itm/290829077542> HP E1938-60201 Ovenized Crystal Oscillator<http://www.ebay.com/itm/290829077542> www.ebay.com HP E1938-60201 Ovenized Crystal Oscillator in Business & Industrial, Electrical & Test Equipment, Electronic Components, Passive Components, Crystals & Oscillators | eBay > > > > > would start with that item since all the support > > > > > circuitry on the PCB > > > > > would have to be re-created by hand. > > > > > > > > > > 2) There's the integrated PCB assembly, as in > > > > > http://www.ebay.com/itm/181043193416 -- which is > > > > > more like what I [http://i.ebayimg.com/images/i/181043193416-0-1/s-l1000.jpg]<http://www.ebay.com/itm/181043193416> HP E1938 Ovenized Crystal Oscillator | eBay<http://www.ebay.com/itm/181043193416> www.ebay.com What you will get is orininal sealed (already tested and calibrated in our lab). Other Countries. UK;GER,CA,USA. | eBay! > > > > > tested. > > > > > > > > > > 3) There's the full instrument version, as in > > > > > http://www.ebay.com/itm/171293069062 -- which is > > > > > most likely to work, > > > > > or be less hacked up, or dented, or salvaged, or > > > > > rusted. It even has > > > > > all the connectors and power supplies, and GPS, > > > > > etc. > > > > > > > > > > If any other time nuts have experience with each > > > > > of these methods to > > > > > obtain a E1938 oscillator, please let us know. > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > time-nuts mailing list -- time-nuts@febo.com > > > > To unsubscribe, go to > > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> www.febo.com time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ... > > > > and follow the instructions there. > > > > > > > > > > > > > > > > > > -- > > Best wishes, > > > > Larry McDavid W6FUB > > Anaheim, California (SE of Los Angeles, near Disneyland) > > > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> www.febo.com time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ... > > 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 time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> www.febo.com time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ... 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.
