Discussion:
Commercially available empty ovens for oscillator testing?
(too old to reply)
Bob kb8tq
2018-05-12 19:33:57 UTC
Permalink
Hi

There are places that sell them. Most are looking for a couple thousand dollars for
one. If that is inside your budget you might get in touch with them. Far cheaper to
get an eBay scrap OCXO and use its parts.

An OCXO depends on the combination of two things to make it stable:

1) The oven holds temperature well

2) The crystal in the oscillator is cut to be *very* flat temperature wise at the oven temperature.

(yes there’s more to it than that, but we’re keeping things simple)

Both are equally important if you are after the sort of thing you see in a normal OCXO.
A typical oscillator may well have a crystal that is 100 to 1,000 times “less flat” than
what is used in an OCXO.

Bob
Does anyone know if there's anyone who sells essentially just the oven &
casing for an OCXO on its own?
I have a project for which I'm currently using a VCTCXO, but I'm
wondering if enclosing a plain VCXO, plus the control DAC & voltage
reference in a single small oven would end up more stable, and possibly
not even much more expensive.
_______________________________________________
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
paul swed
2018-05-12 18:02:56 UTC
Permalink
Julien
Yes you could stabilize the temperature at some level.
But your really adding complexity that will tend to interact.
You have the natural TCXO behavior and then the oven behavior. Hard to say
how it all will behave.

But I suspect your suggesting warming the TCXO to something in its best
stability range. (Center)
Not the typical oven range. It would indeed help. But then even putting the
TCXO in a insulated box would also.
Depends on what you are trying to get to.

I use a GPSDO with a TCXO from Jackson lab and simply insulated it.
It was appropriate for instant on testing and radio references without
wasting power all day long.
If I am more serious I flip to an external GPDO through the same
distribution system after its warmed up.
Typically a TBolt or Z380.

Hope that helps.
Regards
Paul
WB8TSL
Does anyone know if there's anyone who sells essentially just the oven &
casing for an OCXO on its own?
I have a project for which I'm currently using a VCTCXO, but I'm
wondering if enclosing a plain VCXO, plus the control DAC & voltage
reference in a single small oven would end up more stable, and possibly
not even much more expensive.
_______________________________________________
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bernd Neubig
2018-05-14 16:49:43 UTC
Permalink
Hi Julien,

I have a few vintage thermostats from the early 70's manufactured by Northern Engineering Laboratories those days. They come in a cylindrical housing with an "octal" tube socket. The temperature control is done by a bi-metallic switch to +75 degC nominal. Supply voltage is 6V. See attached photos. Inside are two sockets suitable for the good old HC-6/U size crystals (12.35 mm lead spacing)
I have measured the response at one sample giving the following results:
Power consumption < 6 W
after warm-up : 2.2 W
If isolated with styrofoam: 1.5 W
Switch-on/off after warming up 12 sec/22 sec
temperature max-min after warm-up: 0.3degC peak-peak

If such a device is suitable for your needs, let me know by direct private mail

Best regards
Bernd DK1AG



-----UrsprÃŒngliche Nachricht-----
Von: time-nuts [mailto:time-nuts-***@febo.com] Im Auftrag von Julien Goodwin
Gesendet: Samstag, 12. Mai 2018 18:55
An: TIme Nuts <time-***@febo.com>
Betreff: [time-nuts] Commercially available empty ovens for oscillator testing?

Does anyone know if there's anyone who sells essentially just the oven & casing for an OCXO on its own?

I have a project for which I'm currently using a VCTCXO, but I'm wondering if enclosing a plain VCXO, plus the control DAC & voltage reference in a single small oven would end up more stable, and possibly not even much more expensive.
_______________________________________________
time-nuts mailing list -- time-***@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Loading...