This is a forwarded message - reply directly to Clark Savage Turner WA3JPG
at <firstname.lastname@example.org> - - do not reply to me.
Ed Guzis, W9TW
From: Clark Savage Turner WA3JPG <email@example.com>
Subject: asymmetric filter in OMNI
Date: Tuesday, January 20, 1998 8:47 PM
Gee, it is great to be in touch with so many thoughtful
hams on this group. I posted my question about the different
"tone" of LSB and USB on my OMNI VI and find that many others
experience the same thing, the consensus is that the main
SSB filter is not symmetrical, and that makes sense to me.
Thanks to all who went and turned the rig on to listen to it,
and thanks to all who helped calm me down about it, hi hi. I
can sometimes be a perfectionist, and I feel rather let down
to discover many of the real world engineering compromises.
But you won't get my OMNI VI until you pry it from my..... well
you know the rest :-) .
I went over to my trusty Kenmore TS 440 appliance (well, not too
trusty, it won't transmit this week) and played around with that
receiver. It sounds a bit better, but the filters I am using are
wider, a pair of 2.7 kHz filters, the main filter in the 455 IF
is a ceramic with a wide berth (not a hot shape factor) and that
probably hides some of the effects. It was close, but could not
be adjusted to "perfect" either. So, some say that the Collins
mechanical filters were developed for properties of symmetry?
I wonder if I can get one about 2.4 kHz wide with Z in/out of
about 200 ohms and fairly low loss :-) :-).
Thanks all for the responses.
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