Hi Regardless of who made it, OCXO’s often don’t do well after being knocked around. The process of puling them off pcb’s is stressful to the internals. The shock and vibration in normal “junk box” storage can be an issue. As a result, the original performance data may not be of much use.
I’ve tested a lot (like hundreds) of surplus OCXO’s. Well under 10% of them met their original performance specs. That’s just for the stuff I can test in the basement, with better test systems, the total would be lower. Pinout wise, the ground pin *should* be easy to spot. Normally it’s bonded to the case. Once you have it identified, start looking at pinot diagrams for similar sized OCXO’s. It may fit a standard pattern. That would give you a guess for the +12V pin. Hook up with a supply set to about a 1.2A current limit. Apply 12V to the assumed supply and ground. The part probably pulls < 1A and almost certainly pulls < 1.5A. After 10 minutes on power the current should start to cut back. If the case gets really hot (like you can’t touch it for the count of 5) then something probably is wrong …. Once you have it on power, a ’scope hopefully will spot the output pin. If it’s a sine wave, running without a load may give you a pretty distorted output. 50 ohms is a good guess for the load. The EFC pin should look like a high resistance on an ohm meter. It may or may not have a bias on it when the device it powered. Feeding it 0 and 2.5V while watching the output on a frequency counter should let you ID it. After running the device for a day or three, “tune” the EFC to whatever voltage gives you 10 MHz. That’s the center voltage for what you have, regardless of what it was when it left the factory …. Lots of fun !! Bob > On Aug 22, 2020, at 8:34 AM, Paul Boven <[email protected]> wrote: > > Hi again, > > Replying to myself: > > More online searching has revealed that 20TQG01 is likely a date code (week > 20 of year 2001, charge G?). The other identifiers printed on the OCXO are > '7368' and 'EO10391410'. > > On 8/22/20 11:56 AM, Paul Boven wrote: >> Dear time nuts, >> In my surplus drawer, I found an OCXO which I would like to use for a >> home-built GPSDO. The part in question is a 10 MHz, 12V OCXO, type 20TQG01. >> It came from a flea market, and looks to have been removed from a PCB. It's >> fairly large metal case (h = 2.5cm, w = 4cm, l = 5cm) and has 7 pins. >> According to the seller, it achieves 1.2 ppb (!). >> Unfortunately, the Telequarz group no longer exists, and I've been unable to >> find anything resembling a datasheet. Any further information would be very >> welcome, especially pinout and performance parameters. >> Regards, Paul Boven. >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
