[RTTY] RTTY 23 - Someone please kill it!

[Don Hill AA5AU]

Andy et al,

Perhaps I was a bit harsh in my first post.  I hope I didn't offend anyone.
That wasn't the intention.

I know several people put a lot of time and effort in developing these new
modes, which is fine.  I thank them for that and hope they continue to create
new modes for us to try.

I think the tuning problem could be solved with a better display or tuning
indicator.  At first it appears to be difficult to tune, but it's just like a RTTY
signal except it's very tiny on our displays.  AFC didn't help much either.

You need both a fast and slow AFC.  You need a fast AFC to tune in
a signal.  You need a slow AFC or none when calling CQ.  I noticed that
when I go to receive after CQ'ing, the AFC wonders off frequency so fast
that if someone does call you, by the time the AFC locks onto the signal,
you've missed the callsign.  Many stations, including myself, resorted to sending
a short string of RY's at the start of each message to allow others time to
tune.  This is, of course, a step in the wrong direction.

The problem I see is on receive.  A weak signal is barely printing, then someone
fires up .5 khz away and you lose the signal.  I was using a Kenwood TS-870
trying both regular sideband filter in its narrowest position 400hz (1000hz on the
low side, 1400 hz on the high side) and the PSK filter which is 300 hz, but
neither seemed to help knock down nearby signals.  I know many radios can
use the CW filter in SSB mode and this may help.

Another problem I notice is that if the signal takes a hit, it seems to take a longer
period of time for the receive to recover, missing a lot more characters than the
normal 170 hz shift.  I'm not sure why that is.

The problem with this exercise is that everyone is pretty inexperienced at this
new mode and settings are not correct.  Only a handful of stations actually came
back to me on the same frequency I was transmitting on.  Most were off by a lot
which means no print.  With 170 hz shift, you can be off quite a bit and still get
some print.

I saw that George, W1ZT, commented that he likes transmitting AFSK and
has worked on filtering solutions.  I was using an external JPS NIR-12 that 
knocked the audio down to just a sliver of bandwidth and it helped, but as soon
as someone came on within .5 khz, weak signals would disappear!  Maybe it's
my radio, I don't know.  I do know that I can sit next to a station running a KW
at .5 khz and barely notice he's there if I'm running my 250 hz with my radio 
in the FSK mode.

23 hz RTTY probably would work quite well if you could build it into the
FSK part of your radio.  Problem is convincing the radio manufactures to
go to the expense of adding it (maybe they will!).

Until then, the mode seems too difficult to work for us old time 170 hz
STEAM RTTY ops.

I think there's a few more hours left in the contest.  I'm going to jump in
and play around with it some more.

73, Don AA5AU

----- Original Message ----- 
From: "Andrew J. O'Brien" <obrienaj@netsync.net>
To: "Don Hill AA5AU" <aa5au@bellsouth.net>; "Digital DX (new)" <digital-dx@mla.nifty.ne.jp>; <rtty@contesting.com>
Sent: Saturday, September 01, 2001 5:01 AM
Subject: Re: [RTTY] RTTY 23 - Someone please kill it!


> Thanks for the comments Don.  We ran this contest primarily to test out 23
> Hz RTTY. Bob (the 9K2/KM5FY you worked) who authored Zakanaka, and other
> digital software authors added narrow shift RTTY to their software in the
> belief that it might be of some use.  The contest was established to do a
> bit of research that could form the basis of some refinements to the "mode".
> 
> 73 de Andy KB2EOQ
> CCCC Contest.
> 
> 
> ----- Original Message -----
> From: "Don Hill AA5AU" <aa5au@bellsouth.net>
> To: "Digital DX (new)" <digital-dx@mla.nifty.ne.jp>; <rtty@contesting.com>
> Sent: Saturday, September 01, 2001 1:19
> Subject: [RTTY] RTTY 23 - Someone please kill it!
> 
> 
> > OK, I have had my introduction to RTTY 23.  Someone please explain
> > it's advantages.  It's just like PSK31 but without error correction.
> Sure,
> > I've worked some nice stations like N7UVH, UX0FF, ZL2BR, 9K2/KM5FY,
> > RK6BZ, W1ZT, K4GMH, SW1XV, UW5U, HB9AWS, W9HLY, MM0BQI,
> > SP1MHV and UA6JR/3... but it was a real struggle.
> >
> > I'm not really sure what the objective is of this exercise.  Yes, contacts
> can
> > be made using RTTY 23 but it takes lots of power and very narrow filters
> to
> > do it.  It's an AFSK mode - enough said.
> >
> > I'm sorry guys & gals but RTTY 23 appears useless.  Someone please
> > kill it and put it out our misery.
> >
> > Thanks,
> > Don AA5AU
> > http://www.geocities.com/aa5au/
> >
> 
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