I respectfully disagree with Don Kirk. My experience has been different. I
don't how many pileups I've broken quickly - where the station I'm trying to
work is operating simplex - by going split and transmitting a few Hz above
or below "zero beat". The operator at the other end is trying to copy a
callsign, and if everybody is "zero beat" it makes it very difficult to copy
anybody. Anything you can do to make your signal "stand out" or
differentiate it from the crowd makes it easier for the station you're
trying to work. (Also speeding up or slowing down a few WPM sometimes
helps.)
Someone taught me this a long time ago, and it works. He's worked a lot of
good DX in the last sixty (60) years or so.
73,
Marsh, KA5M
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Don Kirk
Sent: Thursday, December 7, 2017 10:17 AM
To: MR TREVOR DUNNE <ei2glb@eircom.net>
Cc: Gary@ka1j.com; topband List <topband@contesting.com>
Subject: Re: Topband: ARRL 160
Hi Trevor,
Besides your TX antenna, another issue I have observed over the years is the
importance of being as close to zero beat as possible. The modern HF radios
offer very narrow RX filtering options, and during very crowded band
conditions most of the stations are running very tight filters and I find
that if I'm off zero beat by much more than 100 hertz I'm often not heard.
I use a very old HF rig and run a 500 hertz filter, and found myself having
to continuously adjust my TX frequency until I popped into the passband of
the station I was trying to work (very difficult to zero beat my radio in
any kind of timely fashion). I finally installed an audio filter (Hi-Per
Mite) with 200 Hz bandwidth and this has basically fixed my problem (99.9
percent improvement).
Previously it was very frustrating hearing a station 20 dB over S9 that
could not hear me. I originally thought they were using an RX antenna not
pointed my direction, but most often I was just not in their RX passband.
Just another possibility.
73,
Don (wd8dsb)
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