[time-nuts] HP 10811 40 Hz low.
paulswedb at gmail.com
Thu Dec 15 20:57:39 EST 2016
Took your advise and did check all of the caps in teh oscillator along with
resistors. All are as they should be. Though they do differ from the
schematic I have for the HP 10811. But thats normal reality on HP stuff. So
it is a sick 10811.
So at this stage I have jacked a external 10 MHz reference into teh system
to replace it and the rest of the Z3801 seems to be working. It needs more
time but did acquire satellites. It hasn't locked yet and unsure it can
with an external reference unless I use the TBOLT 10 MHz. Kind of liking
Since the oscillator was bad and thats how I received it several years ago
the DAC is at 99.99% full scale because it was 40 Hz low. Want to reset
that to mid range.
Also I speculate the actual gps receiver is down on sensitivity but I do
On Wed, Dec 14, 2016 at 7:10 PM, Bob Camp <kb8tq at n1k.org> wrote:
> Crystals do indeed fail. In the case of 40 Hz low, I’d look for a shorted
> cap in series with the crystal.
> > On Dec 14, 2016, at 5:23 PM, paul swed <paulswedb at gmail.com> wrote:
> > I have a hp z3801 that is spare parts it never worked correctly. Did some
> > digging and at least one major issue is the actually HP 10811 is 38 Hz
> > It needs to be within a Hz. Checked everything feeding voltage and such
> > they are solid at 5.7V from the regulator. The varicap works as expected.
> > Signal levels out are clean and correct. Temp is about 82C also inline.
> > The oscillator is actually fairly simple. Do xtals just fail after many
> > years?
> > May see if I can map a Piezo oven oscillator into the z3801 just to see
> > what if anything happens. Now that I know the warm oven signal drops
> > 22V to 3.8V when hot. Fake it out.
> > Not sure the outer oven actually matters on the z3801. But even that can
> > actually be hooked up to make any circuit that might want to know thats
> > hot happy.
> > Regards
> > Paul
> > WB8TSL
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> and follow the instructions there.
More information about the time-nuts