[time-nuts] Still looking for a schematic drawing for Oscilloquartz 8600-3 (945.860.011.03 S/N 422)

[Jim Harman]

If I had to guess from the photos, I would try the resistors on standoffs
next to the 20K pot at the bottom of the photo OSC_02. I assume the pot is
the frequency adjustment.

On Thu, Oct 25, 2018 at 8:38 PM paul swed <paulswedb at gmail.com> wrote:

> Hello to the group.
> Ulf looks like a lot of people are trying to help.
> Earlier in the thread it was mentioned that there often is a tuning cap of
> some fixed value.
> I have actually slightly adjusted those to fix as an example a HP 10811.
> Typically its a single cap.
> But it can't hurt to try changing it if you can figure out the cap.
> Regards
> Paul
> WB8TSL
>
> On Thu, Oct 25, 2018 at 7:14 PM Bob kb8tq <kb8tq at n1k.org> wrote:
>
> > Hi
> >
> > One fairly real possibility - it can’t be repaired. The  tuning range of
> a
> > BVA based oscillator is pretty
> > small. It may be that the crystal has simply aged further than it can be
> > tuned.
> >
> > Assuming the device is still operating properly, there are a lot of uses
> > for a working “1Hz off” 5 MHz
> > OCXO …..
> >
> > Bob
> >
> > > On Oct 25, 2018, at 3:38 PM, Mark Goldberg <marklgoldberg at gmail.com>
> > wrote:
> > >
> > > I agree they likely won't provide a schematic and will want it back for
> > > repair. If it is a proprietary design for someone, they may not even
> > repair
> > > it for you and certainly won't give you any info. I was at least able
> to
> > > get a little info from Wenzel about a similar oscillator I was looking
> at
> > > and they gave me hints about what the one I had was not, basically not
> > > telling me info but keeping me from heading down the wrong path. If you
> > ask
> > > nicely via email and are understanding about their situation with
> > > proprietary products, maybe they will be of some help.
> > >
> > > I have reverse engineered a couple of oscillators. You don't have to
> > > reverse engineer the whole thing, just the frequency adjustment
> section.
> > I
> > > don't know anything about this oscillator but you can determine what
> the
> > > available adjustment is, a pot or a trimmer cap. If it is a pot, is
> there
> > > another resistor that sets the course adjustment? If it is a trimmer
> cap,
> > > there is usually a parallel cap that sets the course adjustment.
> Possibly
> > > those could be replaced with different values to get the adjustment
> range
> > > back. Worth a try.
> > >
> > > If you can look at the circuit around the crystal, you likely can
> > determine
> > > what the oscillator topology is.
> > >
> > > Can you tell if the oven is working? Typically it will draw more
> current
> > on
> > > startup and then reduce the current draw after a while when it gets to
> > > temperature. I've found broken heater wires before.
> > >
> > > Regards,
> > >
> > > Mark
> > >
> > >
> > > On Thu, Oct 25, 2018 at 11:26 AM paul swed <paulswedb at gmail.com>
> wrote:
> > >
> > >> Ulf
> > >> I have no details. But perhaps off list we could reverse engineer it.
> > >> Simply a suggestion. Especially since you have it open.
> > >> Regards
> > >> Paul
> > >> WB8TSL
> > >>
> > >> On Thu, Oct 25, 2018 at 2:15 PM Bob kb8tq <kb8tq at n1k.org> wrote:
> > >>
> > >>> Hi
> > >>>
> > >>> Even with an “account”, most oscillator companies will not supply
> > >> internal
> > >>> details on their product. That’s in part
> > >>> to protect their IP. It also reflects the complexity of tracing back
> to
> > >>> exactly what doc’s apply to an older unit. The
> > >>> normal drill is for you to send it back and they take a look at it.
> > They
> > >>> then quote a repair charge and you either
> > >>> go ahead with it or have them send it back.
> > >>>
> > >>> Bob
> > >>>
> > >>>> On Oct 25, 2018, at 1:56 PM, Ulf Kylenfall via time-nuts <
> > >>> time-nuts at lists.febo.com> wrote:
> > >>>>
> > >>>>
> > >>>> Many monts ago I approached the list regarding an Oscilloquartz
> > >>> 8600-3(945.860.011.03 s/n 422) 5 MHz Ovenized Crystal Oscillator. It
> > had
> > >>> aged and was 1 Hz off and couldnot be braught back to 5.000.000 MHz.
> > >>>> Since I did not have "an account" with Oscilloquartz or what they
> are
> > >>> calledtoday, I was not able to get any help from them.
> > >>>> There was one answer off the list from someone who could possibly
> > >>> helpbut that person either forgot or did not have any relevant
> > >>> informationto share.
> > >>>> A box with the dismantled unit has been laying on my shelf for
> months
> > >>> and I am therefore asking again. If there is no information about
> > >> thisunit
> > >>> available I will scrap it. I do not know of any other forumto ask.
> > >>>> Best Regards
> > >>>>
> > >>>> Ulf KylenfallSM6GXV
> > >>>>
> > >>>> _______________________________________________
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-- 

--Jim Harman