> 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/ 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 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 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. Thanks, /tvb

 On 16 April 2017 at 00:05 Tom Van Baak <tvb@LeapSecond.com> 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/

 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 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 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.

 Thanks,
 /tvb

 _______________________________________________
 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.

Tom #1 proved useful when this sub assembly failed (no 10MHz output) in my E1938A. Someday I'll disassemble it to see what exactly failed. Also have #3 which works well when one figures out the connections on the PCB and the unusual backplane connector. Bruce > > On 16 April 2017 at 00:05 Tom Van Baak <tvb@LeapSecond.com> 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/ > > 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 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 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. > > Thanks, > /tvb > > _______________________________________________ > 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. >

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/ > > 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 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 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. -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland)

Re: schematic. There's a link on the second ebay auction page: http://www.prc68.com/I/pdf/E1938pdfdocs.zip On Sat, Apr 15, 2017 at 10:42 AM, Larry McDavid <lmcdavid@lmceng.com> 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/ >> >> 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/290829 >> 077542 -- and I have no idea where one 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 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. >> > > > -- > 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/m > ailman/listinfo/time-nuts > and follow the instructions there. >

Mention of the E1938 reminded me that I have a schematic that measures 36" X 72" (yes, 3 feet by 6 feet) !! Talk about readability. Also, somewhere, I still have one of them. I'll need to go find it and try firing it up. Now you got me going again ... 73, Dick, W1KSZ Sent from Outlook<http://aka.ms/weboutlook> ________________________________ From: time-nuts <time-nuts-bounces@febo.com> on behalf of Larry McDavid <lmcdavid@lmceng.com> Sent: Saturday, April 15, 2017 10:42:40 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP E1938 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/ > > 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 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 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. -- 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 and follow the instructions there.

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/ >> >> 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 >> 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 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. > >

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/ >>> >>> 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 >>> 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 >>> 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 > and follow the instructions there. > -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland)

 On 16 April 2017 at 13:01 Larry McDavid <lmcdavid@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/

             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
             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
             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
         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
 and follow the instructions there.

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 <lmcdavid@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/ > > > > > > > > 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 > > > > 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 > > > > 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 > > > 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 > and follow the instructions there. >

 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 <lmcdavid@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/

                 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
                 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
                 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
             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
     and follow the instructions there.

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.griffiths@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 <lmcdavid@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/ > > > > > > > > > > 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 > > > > > 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 > > > > > 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 > > > > 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 > > and follow the instructions there. > > > > >

 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 <lmcdavid@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/

                 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

                 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

                 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

             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

     and follow the instructions there.

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-bounces@febo.com> on behalf of Bruce Griffiths <bruce.griffiths@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.griffiths@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 <lmcdavid@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.