There is actually three carriers on the signal you mentioned. The one in the
middle is the
strongest. The two weaker ones about 5hz each side from the middle one. I
always thought it was a
harmonic from some commercial station down in the 5.1mhz range. Sometimes you
can see all 3
sometimes not depending on condx's at the time and what your rig/software can
I turned Autotune off in RITTY and had perfect copy with the weak right side
carrier about 3hz away
with the PROIII set at 350hz bw. The E4X sig was just a little stronger than
the weak right side
carrier with nothing showing on the s meter.
RITTY can also copy single tone rtty, even vy weak ones. Every time I see a
spur I put the mark on
it and invert the signal with perfect copy. I have been questioned before about
rare dx. One even got on the air and called me a liar when I spotted the T6
when other W's could
not hear him. Right after my spot EU jumped all over him and starting spotting
him. RITTY pulls
them out of the noise and in some cases you can't even see or hear the signal.
I did not log them on 30M. Maybe next time.
------- Original Message -------
>From : Don Hill AA5AU[mailto:firstname.lastname@example.org]
Sent : 5/31/2010 11:04:15 PM
To : email@example.com
Subject : RE: [RTTY] 200 hz filter on RTTY
Test driving a new Icom IC-7600 on consignment from Icom.
Tonight there were several us in New Orleans trying to copy E4X on 10140 kHz.
There was a very
strong steady signal right on his
mark frequency. After a while, the carrier moved down about 40 hz. At that
time, I implemented
the 200 hz filter on the '7600 and
the carrier completely disappeared from the passband and I was able to copy
Something else the '7600 that the PRO III does not and that is the notch filter
works on RTTY with
the Twin Peak Filter turned on.
Didn't help with the signal when it was right on his mark frequency though.
Not much you can do
about that although I have heard
rumors of a modem that could actually copy Baudot hearing only one of the two
tones, but this could
have been a HAL myth.
I think I remember someone, maybe Chen, saying a 200 Hz filter would not work
on RTTY or something
to that effect. Maybe I don't
have the story just right, but it appears to be working great. Too tight for
contesting, but works
73, Don AA5AU
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