Hi If it is a OCVCXO and it pulls > 50 ppm at 80 MHz, it’s got terrible phase noise close in. That’s true with or without the PLL engaged.
Bob > On Nov 12, 2017, at 7:46 PM, Mark Goldberg <[email protected]> wrote: > > Yes, exactly those. With no input, would they be expected to be 4 kHz off? > The spec for the standard part wants the input to be within 1e-7. I would > not expect them to be so far off free running. > > I saw 13 MHz on the 500-14273 and stayed away from those. > > Do you know of any part numbers that use 10 MHz in? Wenzel would not tell > me the exact specs of the 500 series parts available on ebay and only sent > me the specs for the standard 501-14057 that takes 10 MHz. > > I have a couple 8642As and can generate any frequency I want with decent > phase noise, locked to my 10 MHz reference. I could try these frequencies > above. > > Do you know what the pll lock output does when the input frequency is off? > These toggle high for any frequencies I have put in. > > Any other ideas are appreciated. > > Thanks, > > Mark > > > On Sun, Nov 12, 2017 at 5:19 PM, John Miles <[email protected]> wrote: > >> Sounds like he's talking about the small 'bricks' that Wenzel sells with >> internal PLL-disciplined OCXOs. Some of these expect oddball input >> frequencies. Just looking at the 80 MHz parts on the shelf around here, >> 500-14273 wants a 13 MHz input, 500-25010 uses 24.576 MHz, and 500-25009 >> uses 19.2 MHz. So that's probably the issue, if two of them seem to be >> failing the same way. >> >> -- john, KE5FX >> Miles Design LLC >> >> >>> -----Original Message----- >>> From: time-nuts [mailto:[email protected]] On Behalf Of Bob >>> Camp >>> Sent: Sunday, November 12, 2017 2:03 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency >>> >>> Hi >>> >>> I guess my point was more that there is not a VCO / PLL combo in an OCXO. >>> >>> If dropping the supply gets you on frequency, then you have moved things >> a >>> lot >>> with that voltage change. 50 PPM is a lot of delta T on any normal OCXO >>> crystal. >>> That strongly suggests there is something wrong in the control circuit. >>> >>> Bob >>> >>>> On Nov 12, 2017, at 2:52 PM, Mark Goldberg <[email protected]> >>> wrote: >>>> >>>> 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. >>>> >> >> _______________________________________________ >> 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. _______________________________________________ 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.
