Hi If you look at the pictures you can see the oscillator they are using for the 10 MHz. At least as far as I can see it’s markings look like those of a VC TCXO. If you mount the device outdoors (as you must to get it to work) there will be a lot of temperature swings. In if the little oscillator *is* an OCXO, it’s not a fancy one. Between the simple oscillator and the outdoor location, you are unlikely to get very good performance out of the unit.
The Oncore in this device has many of the same issues as ones we have discussed in other GPSDO’s. The design of the one in your gizmo is now approaching 20 years old. The interface strings are well documented and you should be able to tap into the module’s i/o stream to see what’s going on. I would recommend tacking a TTL to USB converter onto it and letting a terminal program show you what is happening. Bob > On May 31, 2015, at 11:58 AM, Vlad <[email protected]> wrote: > > > > Hello, > > Some time ago, I got Efratom/Datum GPS-FC item. The apparatus itself looks > like good quality weather-proof aluminium case with embedded GPS antenna. It > has only one connector. That connector is using to supply the power to the > unit and as well to get 10Mhz signal from it. > > Here is the sticker inside of the devices: > > http://www.patoka.ca/OCXO/GPS-FC-LBL.JPG > > I tried to play with this device, however all my attempts to get 10 Mhz from > it has failed. > > Here is how its looks inside: > > http://www.patoka.ca/OCXO/GPS-FC-PCB.JPG > > > AFAIK, there is Motorola Oncore GPS. I checked the 1PPS signal from that > module and its looks good - I see the 1PPS on my scope. > Also I did check on TP4 on PCB. Looks like its an output from 10Mhz VTCXO. > And I see the sine on the scope. > > I tried to contact Microesemi to obtain some service manual or even schematic > for this unit, but unfortunately its not an option. Microsemi sent me only > this manual: > > http://www.patoka.ca/OCXO/GPS-FC-Manual.pdf > > > Its appeared this units out of support for long period of time. So, I would > ask if anybody knows anythings about it ? Especially I would be interested > about what to measure/expect on control points on PCB. I still hope its > repairable. Thanks in advance ! > > > > -- > WBW, > > V.P. > _______________________________________________ > 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.
