I think this list of Al's is right but the conclusion is pessimistic and not
in the traditional ham spirit.
There are so many good signals on the bands now days that when you run
across a guy who's several KC wide, it sticks out. And in the few cases I
have queried, there is almost always an older Icom in use. So when guys ask
me about RTTY and Icom, I just tell them it's something to check out.
Nothing against Icom - they asked so I noted the concern.
The general argument has always been that AFSK setup is too hard to do,
prone to cockpit error and users can't be trusted to get it right. I think
that personally is nonsense. There is an entire PSK and JT69 band segment
of younger users who have managed to pilot those systems to success without
a crutch like FSK. Maybe it's true, maybe not, but I bet you would agree
that it's hard to find a young RTTY op; and it's hard to find an old PSK op.
But like the Icom old rig wide FSK signal issue, I only have a few data
points so my claim may be in fact nonsense.
What I do know with certainty is that having a clean signal allows more guys
to use the same bandwidth. That running AFSK with modern tools like 2Tone
or MMTTY gives you an exceptional signal regardless of the rig. And that
some guys running "true" FSK in fact have the worst and fattest signals on
the band. For those reasons I believe it's worth the small incremental
effort to get AFSK going over the plug and play FSK.
73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie
-----Original Message-----
From: Al Kozakiewicz
Sent: Monday, October 24, 2016 3:30 PM
To: Lee Roberts ; RTTY@contesting.com ; Don AA5AU
Subject: Re: [RTTY] FSK is bad?
I think the way I would characterize it is as follows:
#1 FSK is limited by the implementations present in commercially available
radios
#2 AFSK is limited by the ability, diligence and patience of the hams using
it
In the long run and with a real world population, #1 usually is the lesser
of the two evils.
Al
AB2ZY
________________________________________
From: RTTY <rtty-bounces@contesting.com> on behalf of Don AA5AU
<aa5au@bellsouth.net>
Sent: Monday, October 24, 2016 4:25 PM
To: Lee Roberts; RTTY@contesting.com
Subject: Re: [RTTY] FSK is bad?
It's all relative Lee. FSK is not bad, it's just the way some radios
transmit FSK causes the signal to be wide. If we all had Elecraft K3's, we
could reshape the FSK signal bandwidth and all would be dandy. But we don't
all have K3's and many of us (including myself) can't afford one anyway so
we are stuck with what we have.
If you do own a K3 and narrow your FSK signal, you are at a disadvantage
during a contest because other stations can get closer to you and cause you
to have to move. If you have a wider FSK signal, stations will not be able
to get as close to you without having receive problems of their own. Thus
your signal will be found and copied by more people. This is an advantage
for wideband FSK users.
Jitter? Not sure I ever lost a contact because of jitter but I suppose it's
possible.
Don AA5AU
From: Lee Roberts <ham@n0sq.us>
To: RTTY@contesting.com
Sent: Monday, October 24, 2016 2:27 PM
Subject: [RTTY] FSK is bad?
When I first started in RTTY, FSK was the thing to do. Now, a lot of
people are saying that it has multiple issues and are now telling me
that AFSK is the way to go. But, I've heard that pFSK has no jitter
issues when using tinyFSK and an Arduino board. Since I've heard that
FSK has jitter issues under Windows, I wonder if jitter is a problem
using FSK in Linux. But, as far as I know, there aren't any Linux
contesting programs that use FSK - fldigi has the option for pFSK though.
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