[TenTec] Wider SSB Filters For Omni VI

Joseph Pursley kf5mc@flash.net
Thu, 27 Aug 1998 16:41:18 -0500


I think I'm missing something here. The reason for narrower filters is
an attempt to keep loud signals in close proximity from interfering .
SSB was never designed to sound like Hi Fi. It was originally designed
to allow more spectrum to be used without interference. Check out the
bandwidth of an AM signal sometime. Depending on circumstances it can
take MORE than twice the bandspresd of a SSB signal. The wider the
filter the wider the received bandpass. Using a 2.9KC  filter for
receiving CW will add to the confusion on a crowded band because instead
of hearing one signal you could be hearing a whole bunch. Cutting it
down to 500hz enhances the narrowness of your bandpass clipping out many
of the unwanted signals. On a band that is dead and working cross town
the 2.9 would sound great but in that case why not use a  super
regenerative receiver. They can tune the whole band at once. I prefer to
hear as few signals at one time as possible. Granted a 3kc filter would
make the received signal much more pleasant to listen to that is if
there are no S-9 stations 4 kc's away yelling OLA OLA OLA!!!! The
problem with The Omni V1 is another one for sure> I have the full
upgraded version and both transmit and receive sound like the bandpass
is about 1KC wide.  Now that is a pain . I prefer to maintain my own
equipment but it is hard when the supplied manual does not include
sufficient information regarding  complete alignment. In my case both
carrier oscillator freqs and main oscillators have been checked and are
within tolerance and it still sounds as though the rig is aligned
somewhere near the edge of the bandpass....

I am interested in the filter discussion and would like to read more
about it.  I am not criticizing something I don't understand, just
interested !.........joe

Clark Savage Turner WA3JPG wrote:


> Don't know how much interest Dave's message generated, but I
> am interested.  Has anyone pinpointed Ten Tec's reasons for
> not recommending an extra 150 Hz on each end of the standard
> filter's skirts?  Is the Corsair I SSB transmit strip radically
> different from the OMNI VI?  The Corsair I uses the 4 pole
> 2.7 KHz filter stock.
>
> I am very interested in a pair of 2.7 or 2.9 KHz bandwidth
> filters for my OMNI VI.  I have worked with George at INRAD
> on the CW filters and he sure is interested in helping us out
> on these things if it makes sense.
>
> As I understand it, some of the guys who have solved the OMNI VI
> "slight chirp" problem, the carrier for CW comes in right at the
> "knee" of the main 2.4 KHz filter and that is part of the problem.
> A slightly wider filter there may be helpful to the CW note in
> such a case.
>
> Any other thoughts?
>
> Clark
> WA3JPG
>
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