[ARC5] Shift-pot RTTY circuit wanted

[Kenneth G. Gordon]

Many years ago, in the 1960s, I was quite active using RTTY both for MARS and for 
amateur radio traffic handling.

At the time, for amateur use, I was using a Heathkit VF-1 VFO, which had been given to me 
and which I had "re-kitted". I remember being surprised at how well the VF-1 worked and at 
how stable it was.

The VF-1 drove my much-modified DX-35, which then drove my BC-610E, modified with a 
304TL in the final, to a full kW input for RTTY.

Somewhere, I had found a very simple "Shift-Pot" FSK circuit which I added to the VF-1, 
and which I keyed with the RTTY gear's keyboard. The setup worked very well and was very 
reliable.

Lately, I have been interested in re-visiting my entire setup, since at the time, I didn't know 
very much about electronics, but despite searching all over the net, and looking in my small 
collection of ARRL Handbooks, I have not yet found that circuit.

Can anyone here help with that?

Ken W7EKB