[GreenKeys] HAL ST 6000?

[Don and Diana Cunningham]

Jeremy,
That is a larger question than this answer, but simply put the purpose of 
the ST-6000 is to be a modem for radioteletype signals.  It will work from 
loop or RS-232 keying levels and "modulate" the radio with radioteletype 
tones, or "demodulate" the RTTY tones from a radio back to the DC loop or 
RS-232 keying levels.  Much more goes on, but it is an EXCELLENT unit, with 
everything built in except the computer (with software) or Teletype machine 
and the radio you will use.  More information on terminal units (another 
name for modem) can be found at www.rtty.com and a much better explanation 
that this simple one.  If you have an ST-6000, hang onto it!  Mine sees lots 
of use, hi.
73,
Don, WB5HAK