[TenTec] RX-340 and Noise Reduction

Jim Reid jimr.reid@verizon.net
Mon, 11 Feb 2002 15:55:47 -1000


Hi all,

Have had the 340/Pegasus set up for about a month now.

Biggest "con":   no DSP noise reduction option!!
The Omni VI+ has a beautiful NR function,  particularly
for CW,  but nothing on the 340.  Where I live,  there is
essentially no "man made"  RF noise to worry about,  but
we are also a loooong way from any DX (Hawaii is the most
isolated QTH on the planet,  nothing closer than a few
thousand miles).  So,  DX is often weak,  lots of F layer
hops to get here,  but bounces off the ocean help,  hi.

Anyway,  I wish for my Omni NR button back!  Now,  would
a Timewave 599zx substitute??  The 340 AGC, is wide open
on a dead band,  and the audio noise output is very high.
Connecting to the dummy load,  still a lot of noise out.
The 340 meter reads at the noise floor,  - 135 dBm or so,
but the IF and audio gain bring it up loud.

The Timewave specs specify the DSP noise reduction is
about 20 dB.  If I turn down the "RF" gain of the 340 20 dB,
I don't see a really noticeable noise reduction,  but this might
not be the same thing.  Don't know what the NR reduction
in the Omni VI+ using their algorithm might be;  ARRL did
not test it in the 1997 review,  nor is their any info in their
"expanded" test report about the DSP NR in the Omni.

So,  is it a good idea to buy a Timewave to mate to the
RX-340?

73,  Jim  KH7M