[RTTY] keyed AFSK? - was: Best RTTY rig?

[WA9ALS - John]

> Actually, there is a fourth mode which is probably used
> more than all the others put together.  That is to take
> the two audio tones and use them to MODULATE a carrier, either
> AM or FM, as opposed to using them to create a frequency-shifted
> carrier.  This method is what was originally called AFSK, and is
> used for VHF FM packet even now.  As far as I know, this
> mode has disappeared from HF - there may be some hard-core types
> using it on 10, but I have never heard it myself.

Bill, why was this done?  I suppose it was more copyable than voice under
certain conditions?

Reminds one of using a code practice oscillator on a 2M repeater...