Hmmmm - I thought SSB was developed by the telephone companies or the military back in the 1930s, rather than by AM ham ops. Maybe I was given wrong information.
Actually it was before 1920, for transatlantic communication on longwave. To get any kind of efficency at all out of the antennas for those frequencies, the tuned circuit had to be so high Q that the bandwidth of the antenna was too narrow to allow a full double sideband signal to pass, so someone at Bell Labs figured out that all the information could be transmitted on one sideband.
I have seen circuit diagrams for balanced modulators in pre-1920 radio books. The SSB signal was basically generated with a balanced modulator and the antenna itself served as the sideband filter.
I think the intended meaning of the message is that it was AM hams who first investigated using SSB on the ham bands and shortwave. There was a short article on SSB in the mid 1930's in QST, with the promise of more articles to come on practical construction. That article was mysteriously cut in mid paragraph, and nothing more was heard of it, nore were there any subsequent followups. SSB began to be developed for HF on the ham bands just after WW2.
