[time-nuts] Re: HP 5065A, no 2nd harmonic.

[paul swed]

And I will bet the smell is as bad as the larger 0106 oven. As I say its in
a sealed bag and not sure how I will recover it. Need the windows open.
The suggestion of buying a replacement is the best even if you do need to
buy 2-3 to locate a good one.
Regards
Paul

On Wed, Dec 1, 2021 at 6:13 AM Askild <megafluffy at gmail.com> wrote:

> Hi,
>
> Just a little warning.
> Included are some pictures of a 10811 where thermal fuse protection have
> not functioned.
> I do not know why, if the fuse did not work, or somebody replaced it with a
> wire, as this was in a HP 8663A that I found in a recycling bin, and I do
> not know the history.
>
>
> Regards,
> Askild
>
>
>
> On Tue, Nov 30, 2021 at 8:34 PM Bob kb8tq <kb8tq at n1k.org> wrote:
>
> > Hi
> >
> > The thermal fuses die on their own far more often than they die
> protecting
> > anything. The fuse is there to provide safety is certain odd situations.
> > The
> > simple answer these days is to replace it with a piece of wire.
> >
> > Bob
> >
> > > On Nov 30, 2021, at 12:05 PM, Larry McDavid <lmcdavid at lmceng.com>
> wrote:
> > >
> > > Do these thermal fuses fail spontaneously or is there a common cause?
> > >
> > > If the "heater" transistor mounting screws were quite loose, those
> > transistors themselves might have overheated and failed. But, a thermal
> > fuse should fail by high temperature...
> > >
> > > Sounds like progress, though. Cold OCXO means low frequency.
> > >
> > > Jared, I sent you a private email with some pictures; did you get that?
> > >
> > > Larry
> > >
> > >
> > > On 11/30/2021 8:03 AM, Jared Cabot via time-nuts wrote:
> > >> Well, I found it, the thermal fuse is open circuit.
> > >> If I briefly bypass it with a jumper wire, the oven pulls the expected
> > current.
> > >> Looks like I need something that will trip at roughly around 115C,
> > rated to 1.0A
> > >> (HP Part number 10811-80008)
> > >> Hopefully I can find something in Akihabara to make it easier to get
> my
> > hands on ASAP...
> > >> Jared
> > > ...
> > > --
> > > Best wishes,
> > >
> > > Larry McDavid W6FUB
> > > Anaheim, California (SE of Los Angeles, near Disneyland)
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