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 ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected]
