Hi Jeff -
I believe you. All our ears are so very different. I have experienced
what you have, there are times that my own ears and brain do a better
job of distinguishing the signal from the noise than the filters (in
some rigs) will. Have you ever profiled your hearing (the curves of
where you hear/where you don't?) I have, by a lot of trial and error,
found that my ears can distinguish signals from noise better at a
slightly lower frequency, so I've managed to get filters with lower
center frequencies (like the roofing filter I use and the Ten Tec (NS)
221 centered down at a 500 Hz note). On many rigs, I prefer to hear
wide open filters, on mine, with these filters and the PBT set just
right, I can get a few more db to my brain with the filters.
I also suffer fatigue from hearing the same frequency all the time and
often just tweak the CW note just a little and the difference perks me
up to hear a bit better ... every few minutes. I probably ought to use
diversity - I bet that is the hot ticket. Just haven't gotten around
to dual receivers and dual antennas here at the QTH yet, too busy with
my acoustic guitars and mandolins lately :-) .
Clark
WA3JPG
On Jun 16, 2007, at 6:19 AM, Jeff Frank wrote:
I have an Omni 6 opt 1, which I like very much, but on weak cw
signals, my experience with the filters seems counter-intuitive. I
almost always have easier and clearer copy on weak cw signals when I
use the 1.8 khz filter vs. the .5 or .25 khz filters in my 6.3 mhz IF.
I've got nothing in the N1 position. Is this the way it's suppposed to
be? I always thought narrowing the filter bandwidth is supposed to cut
down on noise but it seems opposite. Has it got something to do with
receivers that are optimized for adjacent signal rejection vs. signal
to noise ratio? I think I read that somewhere. Can anyone explain this
to me? Thanks.
Clark Savage Turner, J.D., Ph.D.
Professor of Computer Science
Cal Poly State University
San Luis Obispo, CA. 93407
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