[RTTY] A Comment Concerning AFSK

Don Hill AA5AU aa5au at bellsouth.net
Tue Apr 3 21:29:57 PDT 2012


I've always preferred FSK over AFSK when it came to RTTY. This preference has been further reinforced with my exploration into JT65
in the past week or so. I have noticed, at least with my PRO III, that the audio coming from my sound card has to be adjusted nearly
every time I change bands in order to keep the ALC at zero when transmitting. This is a small pain but made a little easier by
leaving the Windows sound control open and by the fact that the PRO III can display Power Out, SWR, ALC, etc all at the same time in
the display.

So it's no wonder to me that we see a lot of bad AFSK RTTY signals during contests (I see bad JT65 signals too so it's not just
limited to RTTY). It easy to see that many people are not looking at their ALC when they change bands or even checking it at all. If
they did, they would probably see right away that they forgot to turn their speech compressor of processor off.

I realize I'm probably preaching to the choir and it's not a gripe, but since I rarely operate any other AFSK modes other than JT65,
I am reminded of how delicate the AFSK operation is.

Steam on FSK! (OK, I realize it's not true FSK, but you know what I mean.)

73, Don AA5AU
http://www.aa5au.com
http://www.rttycontesting.com





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