Man O man I am loosing track here. The s30 makes it a ttl part. So 12 V would have smoked it. Seems like an easy fix for that piece at least. Regards Paul WB8TSL
On Fri, Oct 28, 2016 at 3:28 PM, Peter Reilley <preilley_...@comcast.net> wrote: > That seems the most reasonable thing to do. > > Pete > > > On 10/28/2016 3:20 PM, Tom Miller wrote: > >> It looks like that is the only device that could be damaged by 12 volts. >> Can you find a replacement and try running at 5 volts? >> >> >> ----- Original Message ----- From: "Peter Reilley" < >> preilley_...@comcast.net> >> To: "Discussion of precise time and frequency measurement" < >> time-nuts@febo.com> >> Sent: Friday, October 28, 2016 3:10 PM >> Subject: Re: [time-nuts] Opening an Isotemp OCXO >> >> >> The reason that there was 12 volts on the unit was because I put it >>> there. I should >>> have tried 5 volts first but the only datasheet that I could find said >>> 12 volts. >>> All the eBay units that look the same say 12 volts. >>> >>> Pete. >>> >>> On 10/28/2016 12:53 PM, paul swed wrote: >>> >>>> I confirmed the pin out matches a 74s30 also. An S30 is TTL. Great pix >>>> to >>>> look at. >>>> So 12 V on a 5 V chip is indeed a smoker. Find out why there was 12 V. >>>> OK crazy talk I see a 1K resistor next to the VCC chip. Would anyone be >>>> crazy enough to use a dropping resistor from 12 V to get 5?? Really bad >>>> engineering and I don't actually believe they would. But if true a open >>>> 74s30 would indeed show 12 V on pin 14. >>>> Good luck. >>>> Paul >>>> WB8TSL >>>> >>>> On Fri, Oct 28, 2016 at 12:48 PM, jimlux <jim...@earthlink.net> wrote: >>>> >>>> On 10/28/16 9:13 AM, Scott Stobbe wrote: >>>>> >>>>> The OCXO82-59 datasheet lists 12V supply, 5V clock out, could also be a >>>>>> blown regulator in your ocxo, if it is indeed a 12v model. >>>>>> >>>>>> There you go..the design could use a 74S30 as a driver - it's fast, >>>>>> >>>>> fairly good drive, but runs off 5V. If the regulator is shorted, and >>>>> you >>>>> put 12V on it, it will cook. >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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. >>>>> >>>>> _______________________________________________ >>>> 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. >>>> >>>> >>> _______________________________________________ >>> 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. >>> >> >> >> > _______________________________________________ > 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. > _______________________________________________ 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.