Hi Ron,
I did get a firm quote of $135 each for 10 pieces, with a 12 week lead time!
You had a concern about the output. I asked for the LVCMOS output option
to make it a little simpler, however some care is still needed.
I checked the markings on the oscillator in my O II and found DFA18 HA,
not the Siward part! And I can't find a data sheet for it but I am
fairly certain that it was made by Fordahl.
Yeah, power may have to be provided externally. I wasn't considering
this at first, but keeping it warm all the time would be good. Let's
see... the warm-up drift is 0.1ppm, or 1.4 hz on 20 meters. And the max.
draw during warm-up is 3.6 W, roughly 3/4 amps at 5V. Not sure if we can
pull this from the O II somewhere...
Anyway, this may all be for naught, since there are still too few who
are interested. Don't really want to shell out $1350 + shipping to make
it happen.
Lin,
WB1AIW
Ron Castro wrote:
I would be very interested in participating, and yes, I believe the
"original" Orion used the same oscillator. While the mod on my website
mitigates the problem considerably, it can't really cure it. Looking at the
spec sheet of the AOCJY, it appears to be available in the correct operating
voltage, excellent phase noise. The sine wave output is shown at +2 dBm @ 50
Ohms output load while the original shows 1 V P-P into 10 k Ohms. This
should probably be looked into. Here are the specs of the Siward (I just
noticed my website link needs to be changed):
http://www.datasheetarchive.com/TXO32-datasheet.html
Another minor problem is that the AOCJY appears to be an SMT device, so some
sort of PC board would need to be designed to convert the architecture.
That would be good though since the AOCJY accommodates an external
adjustment pot that should make calibration a breeze. Also because since
its an oven-controlled device, an external 5 or 3.3 VDC regulator/filter
will be needed along with a direct connection to 13.6 VDC so the oven stays
on when the power switch is off.
BTW...did you ever notice that most new Orions are 20 Hz off frequency on 20
Meters? I heard that regularly on the TT Sunday net when I first started
checking in. That's apparently because when they are adjusted at the
factory, the radio is upside down with the cover off and the compartment is
at room temp. Normally that compartment gets to over 100 degrees F without
the fan mod!
A friendly call to TT might be in order to see if these specs will work, and
once done, you should have no trouble finding ten folks who want go in.
Ron N6IE
www.N6IE.com
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