On 12/23/06, Jay Rusgrove <[EMAIL PROTECTED]> wrote:
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, that is really interesting! I'm going to forward the link to the
guys at Flex Radio, as a Software Defined Radio could easily implement
such a method. This could be what we have been hearing.
Thanks for sending that info.
Brian / w5ami
______________________________________________________________
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]
