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[TenTec] RX-340/Orion Comparison

To: <tentec@contesting.com>
Subject: [TenTec] RX-340/Orion Comparison
From: jimr.reid@verizon.net (Jim Reid)
Date: Mon May 19 17:41:17 2003
Hi,

Well now have lots of experience,  not,  hi!

Anyway,  do have the rigs side by side,  and with
a little added mod inside the Orion,  can now have
the 340 fed the exact same RF as the Orion Subrcvr.
This can be either Ant1 or 2 and can be simultaneous
to both the Orion Main rcvr and sub;  or only what
is going to the subrcvr.

The most obvious difference is the apparent high gain
of the 340 IF system;  that gain is controlled by a
separate pot on the front panel of the 340.

Per the 340 spec,  the phase noise of the radio is
guaranteed not to exceed -110db/Hz max at 20 kHz
offset;  and is typically going to be around/better than
-120 dB/Hz.

This compares with the Orion performance,  as measured
by Ten Tec engineering and appearing on the TT web
site at:

http://www.tentec.com/images/compnoise.jpg

>From this TT gives the phase noise spec as:

LO phase noise: -136 dBc/Hz typical from 0.5-20 kHz

Those numbers show a BIG difference in the noise you
really do hear!  And it becomes very obvious when
operating both rcvrs, the Orion Main or Sub,  and the
RX-340 simultaneously on the same antenna,  same
IF BW and same frequency/signal/mode.  To approach
an "audible" S/N apparent equivalence,  the IF gain
of the 340 must be turned down at least 30 dB! (the
dB attenuation of gain is read out directly on the 340
front panel as you turn the gain down).

So far,  I am finding the Orion rcvrs,  both of them to
be absolutely amazing!  And I mean it.  Signals are very
weak as we are rcvg them out here in KH6,  but with
the Orion rcvrs,  the bands are definitely more "lively"
than using my older Corsair II or even the 340! Now
this may just be a perceived (maybe even only
psychological) difference,  but I don't think so.

This is not technical info,  and certainly not a complete,
several mode comparison of the rcvrs,  but it is sort
of a first impression after maybe 10 hours of operation
using the Orion,  both SSB and CW and only on 20 and
40 meters in the evenings  so far.  More to come as I
need to become more familiar with the Orion operation
also,  hi.

BTW,  have tried all I can think of to get a signal out
from the AUX I/O port of the Orion.  Tried using both
the supplied TT cable,  and Donner's Digital Interface
for the Orion.  Also tried reversing the Line In and Out
connectors.  Nothing.........  Also tried plugging into
the sound card mike input connector;  that just resulted
in noise,  hi.

73,  Jim  KH7M


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