[time-nuts] HP105B Help

[Dave Miller]

Thanks Bob,
No rust just a couple of electrolytics leaked taking out a couple of nearby
parts.
Everything else looks very nice.

I might be able to find another 10811 to try. I thought there were
different versions
The specified one was supposed to be special low phase noise.
But I know nothing about this as I am a rookie.

This is the setup as I forgot to post it in original post

5370B
TI
1PPS from HP GPSDO to Arm
External arm
10 MHZ form HP GPSDO to start
Stop is 5 MHz output from HP105B 5MHz
The ADEV is terrible
There is a sawtooth on the Original Phase difference linear residual that
seems very repeatable and may explain the apparent jitter of the output.

Dave



On Sun, Dec 13, 2020 at 4:31 PM Bob kb8tq <kb8tq at n1k.org> wrote:

> Hi
>
> If the inside of the 105 went under water long enough to rust out a lot
> of parts on the boards, it’s a good bet that the 10811 in the unit got
> hit pretty hard as well.
>
> Simple answer: Spend $40 on an eBay replacement for the 10811.
> It should just plug in ….
>
> Bob
>
> > On Dec 13, 2020, at 5:15 PM, Dave Miller <ve7hr at ve7hr.ca> wrote:
> >
> > I am in the middle of resurrecting a HP105B, It is one of the later
> models
> > with an 10811 in.
> >
> > I have fixed the obvious issues like the electrolytics that were missing
> > and other parts that had leads evaporated due to corrosion.
> >
> > The basics seem to work, A not bad looking sine wave etc.
> > But the ADEV numbers are terrible.
> > I am going back to make sure it's not a measurement setup issue. That is
> > good. Just tested another OCXO and the test setup is good.
> > Attached in a link to a .tim file
> > https://www.dropbox.com/s/zebwiqy913v7k0k/HP105B%20test.tim?dl=0
> > I am hoping one of the more knowledgeable folks might suggest where to
> > start looking.
> > I have checked all the other electrolytics and the ESR and capacitance
> > looks good. I think the power supply seemed clean.
> >
> > I have taken out the easy to get boards and cleaned card edges etc but
> this
> > persists.
> >
> > The saw tooth on the original phase is yelling something at me but I
> > don't have a clue.
> >
> > Thanks
> > Dave
> >
> > --
> > 72 de Dave
> > VE7HR
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-- 
72 de Dave
VE7HR