In article ,
dxAce wrote:

Lisa Simpson wrote:

Thank you! What's RTTY?

Radio Teletype

This is a digital transmission mode with a carrier modulated with two
tones. One tone represents "0" and the other tone "1." You have to tell
the decoder several things. First you need to tune it so it properly
discriminates the two tones and give the decoder the right shift. Then
you have to tell it which tone is the "0." Then you need to pick the
data rate. You get all that correctly and if the data is not further
encoded then you can read the text being sent but these days most of it
is encrypted by the military so you will not be able to read it. If you
use a computer sound card the software can do everything except maybe
tuning the radio. Tune in a RTTY and several other modes and the
software will figure the other parameters out and decode it if not
encrypted.

You can read some ham transmissions, ship to shore and maybe the
combination ham /military network that sends personal messages from the
troops if it is still around with the Internet email. You can still get
weather fax sent to mariners.

I used to listen to the news services over HF that used RTTY modes. It
was another way to get world news before anyone else but that all went
to satellite and under the ocean cable with the Internet years ago.

--
Telamon
Ventura, California