[TenTec] My new ORION

Bill Tippett btippett at alum.mit.edu
Tue May 24 10:28:28 EDT 2005


WQ7X wrote:

 >2.With my quiet antenna on 40m (3el Quagi) I get many strong signals and 
at the
same time
week dx signals just above the noise floor.I can't copy some of those week
signals
because of the distortion. However, the reason that most of us purchased Orion
is to be able to receive week signals when strong signals are present.
My Elecraft K2 has no problem with that.Obviously Orion should be little 
better
than K2
(has lower phase noise for instance).

         Mark, I suspect this is related to the same DSP
overload issue.  If you want to try 1.371, I can send
you a copy to see if it solves your problems.  This
is not a good long term solution but it would at least
narrow down the cause of the problems you're seeing.

         Regarding the IC-7800, 4 different testers (ARRL,
RSGB, Sherwood and W8JI) have measured both Orion and
the 7800 at 1-2 kHz spacings and ALL results consistently
show Orion has much better BDR and IMD at those spacings.
Of course these were not done with 1.372 which definitely
suffers from DSP overload.  Incidentally, the K2 also has
problems at close spacings.  Just over one year ago I was
using Orion and a new K2 to listen for YA8G on 1814.0.  I
was quite surprised to hear W1AW (S9+30 on 1817.5) leaking
through the K2.  Additionally, the K2 has phase noise
problems, just like the IC-7800, which cause it to fall
apart at 1-2 kHz spacings even though it is one of the best
at 5 kHz spacings.  You can see this very clearly if you
look at ARRL's Expanded Test Reports for both the 7800
and K2 versus Orion (IMD and BDR swept response graphs).

         Regarding front-end BCI overload on 40m, Europe
is the world capital for these problems.  Many Europeans
have commented on Orion's exceptional performance on 40m.
I believe YT1NT or someone on this reflector said he had a
50 kW BC station very near him and had no problems, but I
cannot find that post at the moment.

         Bottom line - either reserve judgement until the
1.372 bug is fixed or install 1.371 to see if that solves
the problems you are having.  Hopefully 2.0 will give us
both the AGC improvements AND fix the DSP overload issue.
If it were 160 season now, I would probably be running 1.371
myself, but I'm assuming 2.0 will be ready before the
low band season begins next Fall.

                                         73,  Bill  W4ZV



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