[time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[John Miles]

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:time-nuts-bounces at febo.com] 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 <marklgoldberg at gmail.com>
> 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.
> >