[TenTec] Some Observations on Orion Stability/Calibration

[w9ac@arrl.net (Paul Christensen, Esq.)]

> Mine wasn't too far off -- about 15 Hz at 15 MHz.  But that was more than
> that certain far eastern company shipped their equipment with.  Clearly
> the latter company wasn't concerned only with meeting spec.  I have two
> identical receivers from them and both were that good.

My RX-340 is currently about 10 Hz from zero beat at 15 MHz.  Not bad since
I have never calibrated it.  However, a simple pot adjustment will bring it
back to zero beat and will likely stay there without the effects of
vibration from shipping which likely affects calibration.  Of course
on-going aging of a new TCXO will always be a factor.  For a couple hundred
dollars, I figure it's worth having a GPS frequency standard that is
guaranteed to one part in one billion (that's 1 in 10^9).

After a bit of web research I found the following relevant articles relating
to the HP GPS receiver that may be of interest:

http://www.realhamradio.com/GPS_Frequency_Standard.htm

http://www.qsl.net/kt4qw/3801des.htm

http://www.ad6a.com/Z3801A.html