[time-nuts] Vectron Type 229 Crystal Oscillator
GandalfG8 at aol.com
GandalfG8 at aol.com
Sat Jun 23 22:09:32 UTC 2012
Hi Ed
Thanks very much for your suggestions, it had occured to me that it should
be possible to run the oscillator without the oven and if I don't find any
specific information as to actual supply voltages I'll give your
suggestion a try.
That's a great idea re the oven too, followed carefully I would expect that
to identify the minimum voltage quite accurately.
I've found comments for several Vectron oscillators that the maximum output
is limited to +7dB for frequencies over 100MHz. I can't be sure that
automatically applies to this one too, nor that it might not be rated for less,
but at least that's another bit of possibly useful information.
I've written to the seller in the hopes that he might be able to better
identify where it came from, with a bit of luck that might help provide the
answers I'm looking for.
Regards
Nigel
GM8PZR
In a message dated 23/06/2012 22:42:08 GMT Daylight Time,
ed_palmer at sasktel.net writes:
Hi Nigel,
I don't have any specific info on your oscillator. If I was doing it,
I'd investigate the oscillator and oven seperately.
Power just the oscillator and monitor the output while you slowly raise
the voltage from zero. Once the output appears, watch the amplitude as
you increase the supply voltage. In my experience, it will increase
until some point where a further increase in supply voltage has no
effect on output amplitude due to the action of an internal voltage
regulator. Now you know the minimum voltage for the oscillator. Add a
couple of volts for headroom on the voltage regulator.
It isn't as easy to determine the appropriate voltage for the oven.
Start with a low voltage and see if the current ever drops. If not,
raise the voltage in small increments until it does drop. You will
probably have to wait for many minutes after each increment to see if
the current will drop. Now you know the minimum oven voltage at room
temperature. Since it's probably rated for temperatures lower than room
temperature, the design voltage will be somewhat higher.
I've had good luck with this technique. YMMV.
Ed
On 6/23/2012 12:20 PM, GandalfG8 at aol.com wrote:
> I've recently bought a Vectron 229-9268 100MHz crystal oscillator via
> Ebay with no information other than it was supposed to have been
removed from
> an item of Racal radio equipment several years ago.
>
> It has an SMA RF connector and a 7 pin circular power connector, much in
> the style of a B7G valve base, with several leads attached to that which
> terminate at what appears to be a miniature version of a 9 pin D
connector.
>
> A search through the list archives, and online generally, has thrown up
> two different connection options offered in response to previous
requests for
> information on 229-xxxx series oscillators, the first listed as being
for a
> CO-229 is as follows.......
>
> Pin 1 No connection (NC)
> Pin2 Case(0V)
> Pin3 Case(0V)
> Pin4 B+ 24VDC
> Pin5 VCXO Supply For option V models only
> Pin6 VCXO Input For option V models only
> Pin7 VCXO Return/case For option V models only
>
> The second is shown as being for a "VECTRON 229 osc with 7 pin Kovar feed
> through in circle similar to a
> tube base".......
>
> 1 B+ (Oven)
> 2 N/C
> 3 N/C
> 4 B+ (Osc)
> 5 VCXO Supply
> 6 VCXO Input
> 7 return (Case)
>
> Mine looks to be a very close match to the second option, pins 2 and 3
> aren't used, 7 is definitely ground, and there are small decoupling caps
from
> pins 1 and 6 to pin 7, although no decoupling on 4 and 5.
>
> I've seen suggestions for the single power feed versions that the supply
> options were either 12, 15, or 24 volts but have found nothing to
indicate
> whether or not the dual power feed versions would always use identical
> supply voltages, or if they might also have been available requiring
different
> voltages for oven and oscillator.
>
> I'm happy enough to play "suck it and see" with the oven voltage, and
judge
> that by current and case temperature, but would prefer not to fry the
> oscillator as part of that process, bit self defeating really:-), so any
> information would be very much appreciated.
>
> regards
>
> Nigel
> GM8PZR
>
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