[TenTec] Orion/O2 Drift Problem-who is interested in a fix?

[Paul Christensen]

> expensive! The 10 MHz GPS stabilized part is a no-brainer and
> the parts are
> cheap and available.  It's the rest that's a challenge.

I am using an HP 58540A GPS-disciplined OCXO with another brand of 
transceiver.  Of course, stability is excellent but even the best GPS-based 
OCXOs are phase-noise-limited to about -145 dBc @ 1kHz.  Not bad, but not 
great.

For use on general coverage rigs, the performance is probably acceptable. On 
the Orions, I suspect that these units will become a limiting performance 
factor.  However, Jackson Labs has recently introduced a low-noise 
GPS-Disciplined OCXO with phase noise performance about 10 dB better than 
that of the HP units:

http://www.jackson-labs.com/docs/Fury_Flyer.pdf

Probably a better solution for Orion owners who demand exceptional accuracy 
and noise performance is to consider retrofitting a high-stability OCXO with 
an SC cut:

http://www.wenzel.com/datasheets/streamline/501-04608.htm

Note that specified phase noise at 1 kHz from carrier is down about -165 dBc 
with the Wenzel OCXO.  Although they're not GPS-locked, stability is so good 
that they need no ongoing locking mechanism.  It's been a while since I've 
checked on pricing, but none of these options are cheap.  Plan on spending ~ 
$200-$300 USD or even more for any good OCXO.

Paul, W9AC