[Orion] Re: [1000mp] Mark v compared to the Orion + Enhanced S/N at Narro...

Bill Tippett btippett at alum.mit.edu
Thu Apr 22 07:15:55 EDT 2004


DL6KAI wrote:
 >So, my conclusion is, if you have QRM, the Orion is the performer, but i
hope, that one of the next firmware-updates improves a bit the reception of 
weak,
fluttered signals just above the noise level.

Hi Randolf,

         I would probably agree with your QRM conclusion
although I don't have the Pro2 to compare.  IMD and
BDR measurement differences confirm what you are
observing regarding QRM.

         Orion is a little tricky to learn to use for
signals right at the noise floor.  The AGC in
particular must be set correctly or you will have
problems.  I would strongly advise anyone interested
in optimizing Orion's weak signal performance to
read Sinisa/YT1NT's excellent paper here:

         http://www.geocities.com/va3ttn/UsingOrionRX.pdf

Pay special attention to his AGC Adjustments on Page 4.
After you correctly set the Threshold, his recommendations
for Decay of ~5 dB/S and Hang from 0.30-1.00 are especially
useful for VERY weak signals.  I had discovered that Threshold
needed to be set dramatically higher on the low bands, but
I did not realize the dramatic effect Decay and Hang have on
weak signals until I read Sinisa's excellent paper above.

         I've had my Orion 8 months and continue to learn new
things about it almost every day.

                                 73,  Bill  W4ZV




More information about the Orion mailing list