Sometimes I really get curious and want to know about something.

I haven't seen the Ham Radio article, but I'm thinking if the whole
idea had any merit it would be a popular mode by now.

Bruce-

It has been about 35 years since I had a class in school where SSB-FM was
discussed. I recall that if you derive the equations for both AM and FM SSB,
they are identical for practical purposes if the FM signal has low deviation
(low modulation index?).

Looking at Two Meter FM, the deviation typically peaks at about 5 KHz. If you
listen to your local repeater with an SSB rig such as the IC-706, it will be
obvious that it isn't a clean signal! However, a 3 KHz deviation FM signal on
HF (below 29 MHz) will sound much cleaner when tuned as SSB, and you may not
notice it isn't AM-SSB.

With this in mind, consider that AM-SSB and FM-SSB might just be two ways to
generate an SSB signal, assuming you use a filter to eliminate the carrier and
other sideband.

By the way, an IC-706, especially one with the TCXO, often has a more accurate
frequency read-out than a typical Two Meter rig. Therefore you can use it to
check a repeater's frequency by tuning it as if it were an SSB station while
someone is speaking. It is easy enough to check the IC-706 against WWV on HF.

73, Fred, K4DII