[AMRadio] Odd signals in lower 80 meters

[Jay Rusgrove]

Possibly the old NBVM (narrow band voice modulation) system debeloped by Dr. R.J. Harris and
published in QST Nov. & Dec. 1978. There was a limited production run of commercial units, and a
hard sell to the ARRL and commercial SSB users followed, however the concept never caught on.
Imagine there are still units floating around.

A brief overview of the system can be found here:

http://www.qsl.net/vk5br/NarBandVoice.htm

Details are in the QST articles. Being in on the original testing, I can say it was darn near
impossible to get any intelligence from the 'folded over' signal.

Jay W1VD