Topband: Omni VII performance on 160m
Svein Nordhuus Moe
sveinmoe at online.no
Sat Jun 30 15:01:57 EDT 2007
I tend to agree with you.
The proposed concept of "Distributed Roofing Filter Architecture" seems
To me this seems to be an oridinary general coverage radio design with
20KHz roofing filter and some ordinary filtering further down the signal
Since its made by TT it is likely to be better designed than many of the
Japanese machines, and that seems to show up in the measurements as well.
Seems they have adjusted the total signal chain to give the best
possible result within the inherent limitations of a wideband-input radio.
The FANTASTIC feature of this radio though is the Ethernet remote control.
This feature alone plus the CW break-in features would be enough to have
the radio for general use if not for extreme160m DX-ing.
BTW. I have both the K2, and the now rather old TT OMNI-D from the 1980's.
An acid test for CW DX radios in my view is the CQWW on CW. The
broadband (out-of-filter-bandwidth) signal-pressure on the radio is
tremendous at peak CQWW hours. Although the K2 is one of the best radios
around today, those are the few days when you will experience filter
blow-by in the K2. There are birds singing at a constant level in the
background wherever you tune along the bands. You will feel some of the
same broadband noise pressure in your headphones on a noisy winters day
on 160. The old OMNI-D on the other hand just delivers the stations
clearly both on CQWW and on other days on 160. And the 2nd hand price is
only 300 USD or less. It does have its own small flaws, like the AGC
handling of extremely large signals within the filter band, but on
average this is my 160 favourite. Seems that they started out by
optimizing the radio for 20m and then reduced the sensitivity for each
band down to 160. This matches the the noise level that you are likely
to experience on the bands quite well, and it may save your ears.
73 de Svein, LA1SJA.
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