The standard oscillator, 501-14057 ( www.wenzel.com/wp-content/parts/501-14057.pdf) will lock to an external 10 MHz reference and this one is marked "80 MHz" and "15V on the label. Maybe someone swapped the labels. I did try lowering the supply voltage. It got to 80 MHz at about 11V and still did not lock to the reference. This oscillator is specified at 1e-6/year aging. That is way less than it is off now.
Mark On Sun, Nov 12, 2017 at 12:34 PM, Bob Camp <kb...@n1k.org> wrote: > Hi > > It’s pretty certain that there is no PLL inside an 80 MHz low phase noise > OCXO. > If it is 4 KHz off frequency at 80 MHz, that gets you into the 50 ppm > range. Either > it is running on a really odd crystal spur or it’s not at the right > temperature. Drifting > around by 100’s of Hz ( = ppm’s at 80 MHz) is also a good indication that > the oven > is not doing it’s job correctly. > > If multiple units do the same thing, either they all got busted being > puled from gear > (unfortunately that’s common) or you are running it at the wrong supply > voltage. > > Bob > > > > > On Nov 12, 2017, at 1:19 PM, Mark Goldberg <marklgoldb...@gmail.com> > wrote: > > > > The seller has replaced it with one that does the exact same thing, which > > is weird to have two fail in the same way. They are getting hot and the > > frequency varies with the input voltage, so I tended to guess not the > > heater as I don't think it could pull that far over temp, and it always > is > > high. If it has an unlocked PLL on the output, with no control, would it > go > > to the max frequency? Since the seller seems to be reasonable, I was > trying > > to figure out best not to waste both of our's time, and me get a good > unit > > and them getting a sale. > > > > Mark > > > > > > On Sun, Nov 12, 2017 at 9:22 AM, Bob Camp <kb...@n1k.org> wrote: > > > >> Hi > >> > >> As a guess - the oven circuit has stopped working. Next step > >> would be to tear it open and trace out the schematic. After that > >> make reasonable guesses for any parts that are poorly labeled. > >> > >> Much of what shows up on eBay has been through the ringer in > >> China. A high percentage the OCXO's I get on eBay show up with > >> issues as a result. There is no way to be sure this or that part was > >> ok before it came out of the gear it was in. It’s always a gamble. > >> > >> Bob > >> > >>> On Nov 12, 2017, at 10:41 AM, Mark Goldberg <marklgoldb...@gmail.com> > >> wrote: > >>> > >>> I have obtained a couple 80 MHz Wenzel Oscillators P/N 500-16423A. They > >> are > >>> proprietary but similar to the VHF PLO and 501-14057 Oscillators. I > want > >> to > >>> use this to replace the internal oscillator in my Perseus SDR, for > better > >>> accuracy and maybe better phase noise. Both of these are way off in > >>> frequency, about 4-5 kHz high from the ideal 80 MHz, and drift around > >>> hundreds of Hz. I believe they are broken in some way. The PLL lock > >> signal > >>> toggles when I put an input into the 10 MHz reference, but the output > >>> frequency is not affected. > >>> > >>> Wenzel has answered some of my questions, but can't get specific as > these > >>> are proprietary to a customer. > >>> > >>> Any experts on these oscillators out there? > >>> > >>> Thanks, > >>> > >>> Mark > >>> _______________________________________________ > >>> 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. > > _______________________________________________ > 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.