[time-nuts] AN/URQ13 reference AT cut crystal?

[paul swed]

Bob
That being said then this thing is way off in temp and I wonder if I can
even get it to any place close. That suggests disconnecting the oven
controller and manually controlling the heating element. The inner is 80
ohms nichrome and the outer 39 ohms. Inner is actually far easier to mess
with and to also add thermocouples and such to monitor.
If I understand this correctly as I drive the temperature up I think the
crystal will go lower in frequency. The oven heater is driven off the 15 V
supply and ground. But You would almost have to use the +15 to -15 to get
enough current I suspect. The last darn issue is why is the inner oven
meter reading in the normal range? That defies logic.
Quite the mystery/puzzle, just whats needed as the winter storms come
through.
Regards
Paul.

On Tue, Feb 16, 2021 at 9:11 PM Bob kb8tq <kb8tq at n1k.org> wrote:

> Hi
>
> The temperature of the crystal is driven by the oven design. AT / SC / BT
> / IT
> or whatever …. it is going to be over 80C. It’s not a function of the
> crystal. It
> is what the physics of the oven force you to do. Inner oven *must* be
> hotter
> than outer oven. Outer oven *must* be hotter than the maximum ambient of
> 50C.
>
> Bob
>
> > On Feb 16, 2021, at 6:17 PM, paul swed <paulswedb at gmail.com> wrote:
> >
> > Hello to the group still working and decoding the AN/URQ-13 reference
> > oscillator. Bob had mentioned that the crystal should be at 85 C and
> thats
> > right for a SC cut crystal. Would there be any reason that this
> oscillator
> > is perhaps a AT cut crystal thats in the 30 C range. Just odd that the
> > front meter reads in the normal temperature range and the real
> > measurement is 40C. Makes no sense but they build AT cut crystals for
> some
> > reason.
> > Ehat about the smaller ovens like Piezo's. Pretty sure I can find many
> > details on the Morion oscillators like the MV200.
> >
> > Other bits of details.
> > There are 2 discreet regulators that simply produce most likely a low
> > noise +/-8.5V. The Oven heaters seem to run on +15V and the divider
> analog
> > circuits need 13V min to work. But not 15V. That seems to cause some
> > distortion.
> > The other circuit on the board attached to the oscillator is a buffer
> amp.
> > It does have several meter resistors on it also.
> >
> > Regards
> > Paul
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at lists.febo.com
> > To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>