From: "Ralph Mowery"
Organization: EarthLink Inc. -- http://www.EarthLink.net
Newsgroups: rec.radio.shortwave,rec.radio.amateur.digital.misc ,rec.ham-radio
Date: Sat, 12 Feb 2005 15:49:40 GMT
Subject: Rtty Protocol


"Greg" wrote in message
...


Okay, I have some questions about RTTY:

1. What unencrypted RTTY traffic is out there besides hams?


I am not sure about RTTY that is not ham now. I doubt much is in use.
There used to be some using other shifts and upside down from the ham
standard.
You may find a list on rtty.com

2. What sort of encoder would I need to read RTTY with my NRD-525 and
what
do I need to know to get it functioning?

YOu can use your computer with the built in sound card. There are several
free programs you can use . MMTTY is a good one to start with.

Go here to get the programs.

http://www.muenster.de/~welp/sb.htm

YOu just hook the sound card input to the speaker or output of the receiver.
Even a mic on the computer layed next to the speakers will work in a quiet
location.


3. My receiver has an RTTY mode. What exactly does that do in my
receiver?
Couldn't I just use USB or LSB?


The reciever will go to either the LSB or USB mode but the filters will be
shifted so they will be centered at higher audio frequencies. The normal
ham rtty audio tones are 2125 hz and 2295 hz for the normal 170 hz shift.
In real use the receiver could be tuned so that almost any lower frequencies
are comming out of the speaker and the demodulator (converter or sound card
freqwuencies) set for the lower frequencies. The way it was done in the
precomputer days were with fixed filters and it was hard to change the
tuning of them. By using lsb and the mark tone of 2125 (think that was a
multple of some audio tuning fork but not sure) the tuning was simplified.

You can use LSB for most ham and USB for the comercial rtty. You may or may
not be able to use the narrow filters in the receiver. I don't know
exectally how that receiver switches the filers in and out.


Okay, thanks for the info Ralph. I haven't gone to the links yes but I'm
betting there's not a lot of RTTY software for my Apple computer. That's
why I thought of a standalone decoder, like an MFJ or something. But it's
probably not worth the trouble if, as you say, there isn't much RTTY traffic
out there.