"Michael Black" wrote in message
mple.net...
On Sat, 7 Nov 2009, Richard Knoppow wrote:

Around the 1950s Leonard Kahn and others worked out
means of combining the sidbands of a conventional AM or
double sideband suppressed carrier signal using a
synchronous detector. In effect this was a sort of
frequency
diversity. It also reduced distortion due to selective
fading since it regenerated the carrier locally.

Wasn't it Webb at GE that was doing the work on DSB?
That's the name on the synchronous detector article in
"CQ" in the late fifties, and that was either preceeded or
followed by an article about DSBsc in general.

And John Costas of course came up with the Costas Loop for
receiving AM,
and I see he was at GE in the fifties when he came up with
the Loop.


Michael VE2BVW

You may be right. GE did a lot of early work on SSB and
DSB. GE had a very fine research department until John
Welsch killed it.



-- Richard Knoppow
Los Angeles
WB6KBL