[RTTY] FSK & 1000MP & MTTY Problem

[psussmman at pactor.com]

I am not familiar with the 1000MP, but if you are using a computer to
generate the tones and feeding them into the MIC (or external input)
jack you are probably operating AFSK and not FSK.

FSK is usually internally generated by the rig and involves changing
the rig frequency back and forth using a fixed shift. AFSK uses two
audio tones which are toggled through SSB which accomplishes the same
thing. In the case of AFSK on SSB, the modulating frequency determines
the center carrier frequency. Thus it is typical to use a LOWER audio
frequency pair when operating AFSK on LSB.. usually 1200Hz and 1400Hz.
Operating AFSK with standard USB AUDIO tones of 2195Hz and 2395Hz will 
probably be "out of range" on the receive detection frequency of your
input filters on LSB. Thus, no RX print. Of course, when switching
between USB and LSB, MARK has to be reversed.

This is covered quite throughly in a back issue of PACTOR NEWS. 

Need more? Let me know... good luck.

Phil Sussman - N8PS
Editor - PACTOR NEWS

-----------------------------

Quoting NB1B <NB1B at comcast.net>:

> I've been trying to key my 1000MP using MTTY and FSK.  I can get it to work
> using USB and Rev, but I can't get it to work using LSB and nor.  Any
> suggestions that I could try?
> 
> LSB and USB phone both work FB.  I just built the FSK Interface, and the
> signal sound fine on a second rcvr, but all I get when trying LSB and NOR
> are "can't print" replies.
> 
> Its got me stumped.  Just made another RTTY QSO, called several times using
> LSB and NOR, no reply, then switched to USB and REV and the station came
> back in one call.  I think I'm missing something.
> 
> Dennis NB1B