Hi The early HP’s (anything before the 10811 would not have had SC’s in them. Depending on this or that they either had AT’s or BT’s.
Bob > On Dec 8, 2017, at 4:06 PM, Jeremy Nichols <jn6...@gmail.com> wrote: > > My HP-103AR is low (the 1 MHz output reads 0.999 999 200 MHz) with the fine > frequency adjust turned to maximum. I'm a rank amateur at this but the > circuit diagram looks like a series-resonant (Pierce) oscillator. Looks > like I need to replace one of the capacitors inside the oven with a smaller > value. > > > On Fri, Dec 8, 2017 at 12:40 PM Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >> One basic question - Is the frequency high or low? >> >> Assuming it’s an SC and on the lower turn, frequency low is possible >> with an off temperature oven. Frequency high is unlikely unless it’s *way* >> off temperature. How far off turn gives you how much delta F depends on >> the inflection temperature of the crystal. It matters if it’s a “true >> SC”or a >> “modified SC”….. If it is a true SC and running at 80C, that’s about 10 >> degrees >> below inflection. There will not be a lot of frequency change in that case. >> >> Many (but not all) modern crystal processes tend to age positive. If that >> is the >> case on these parts, a frequency high is the likely outcome of “age out of >> range”. >> Even with a process that has a known tendency, only about 70% of them go >> that direction over long periods of time. It’s not a perfect thing …. >> >> Bob >> >>> On Dec 8, 2017, at 2:34 PM, Angus <not.ag...@btinternet.com> wrote: >>> >>> >>> The 8601 that I have was about 2 deg C off turnover when I got it, but >>> I can't remember what sort or frequency error that caused. The >>> temperature coefficient was terrible with that error. >>> >>> Angus. >>> >>> >>> On Fri, 8 Dec 2017 13:05:14 +0000 (UTC), you wrote: >>> >>>> >>>> Gentlemen, >>>> We have an Oscilloquartz OCXO 8600-3that cannot any longer be adjusted >> into 5,000,000 Hz.It is about 1 Hz out of 5 MHz and turning >> coarse/fineadjustment potentiometers cannot bring the frequencyinto its >> specification. >>>> Oven temperature is about + 80C accordingto the thermistor and the >> operating voltageis at 24 VDC. >>>> Have Googled but the only thing that turns upis datasheets w/o any >> details. >>>> Before I take it apart and start lookingfor obviously broken >> components, isthere anyone that has a CLIP on this unit? >>>> 73 >>>> >>>> Ulf Kylenfall - SM6GXV >>>> _______________________________________________ >>>> 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. >>> _______________________________________________ >>> 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. >> >> _______________________________________________ >> 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. >> > -- > Sent from my iPad 4. > _______________________________________________ > 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. _______________________________________________ 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.