[TenTec] Some Observations on Orion Stability/Calibration

[Eric F. Richards]

At 09:30 PM 6/3/2003 -0400, Eric Scace  K3NA wrote:
>    If folks are particularly interested in frequency accuracy, a recent 
> issue of "QEX" discussed how to setup a GPS-slaved time &
>frequency standard.  A readily available surplus unit (used in the 
>cellular telephone industry) was featured in the article.  The
>unit provides a high-accuracy 10 MHz signal and time-of-day.  These have 
>been advertised in "QST" and "QEX" for about $265 over the
>last year or so.  Achieving a stable and accurate local standard based on 
>this little rack-mount box would be much easier than
>WWV-based solutions.

I use one of these with my RX-340, where it literally is a plug-n-play
solution.


>    A very ambitious person would devise a system for slaving the Orion 
> TCXO to an external 10 MHz standard.
>
>    I have used double-oven 10 MHz local standards (also retired from the 
> telecommunication industry) whose accuracy was tracked
>against WWVB at 60 kHz with a chart recorder.  This approach is accurate 
>enough to observe the daily aging rate of the crystal
>(after a few days of measurements).  A WWVB-based calibration mechanism 
>would also be quite accurate, but it does require a recorder
>and more time.  The GPS-slaved system is much faster, which is why it is 
>in common use today.
>
>-- Eric K3NA

This receiver seems to be a single oven but is highly accurate and has
low phase noise.  Software beyond the basic SCPI command set can be found
at http://www.realhamradio.com/gpscon.htm to control as well as chart
accuracy over time.

The receiver itself is available from www.buylegacy.com and at $249 is
a no-brainer when compared to the $4k rig it is used with.  The manual
is online at buylegacy.

Eric

--
Eric F. Richards
efricha at dimensional.com
"The weird part is that I can feel productive even when I'm doomed."
  - Dilbert