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July 25th 03, 08:52 PM

(Brian Kelly) wrote in message . com...
"Elmer E Ing" Elmer E wrote in message news:gk0Ua.11280$ff.3485@fed1read01...
Thanks Keith I'll add those to the copout list.

BTW SSB is probably 30 or 40 years old.

SSB first showed up in the ham bands in 1934. AT&T had SSB running
around ten years before hams did.

However, the AT&T operations were fixed-frequency LF systems (5000
meters). HF SSB was not used by the telephone folks until the '30s,
when about a half-dozen systems were put in service.

One of the reasons AT&T went with SSB for the LF transatlantic
telephone was antenna bandwidth. A 6 kHz wide AM channel at 60 kHz
involves an antenna bandwidth of 10%.

Hmmm...self-funded basement-workshop hams were less than 10 years
behind AT&T and its nearly-unlimited resources...

Next year will mark the 70th
anniversary of ham SSB. Gawd I love these "new, modern modes" like SSB
which make Morse such an artifact mode . . .

Yup - and the theoretical background for SSB goes back even further.
Truly an antique mode.

Here's a timeline:

1910 - G.A. Cambell (of AT&T) develops LC filters suitable for SSB in
the LF
range.

1914 - G.R Eglund (of Western Electric) sketches geometric
relationship of
carrier and sidebands.

1915 - J.R Carson (of Western Electric) describes mathematical
foundation of
modulation and shows the theoretical advantages of SSB suppressed
carrier
transmission.

1915 - Carson files for patent on SSB.

1917 - Experimental 3 channel SSB telephone carrier system installed
between
Maumee Ohio and South Bend, Indiana.

1918 - "Type A" SSB telephone carrier system installed between
Pittsburgh PA
and Baltimore MD. Four channels using LSB between 5 and 25 kHz. Type A
was the
first nonexperimental commercial use of SSB, and eventually seven Type
A
systems were installed, remaining in service until the 1940s

1923 - Experimental one-way LSB 60 kHz radio system demonstrated
between Rocky Point, L.I.,(New York), and London. Many of the
components, including tubes, for this system were developed by Western
Electric.

1927 - Regular transatlantic telephone service using 60 kHz LSB put in
service.
Transmitting stations at Rocky Point and Rugby, England. Receiving
stations at
Houlton, Maine and Cupar, Scotland. A three-minute call cost $75.

1932 - Carsons's SSB patent granted (17 years after filing).

1933 - Robert Moore, W6DEI, puts an amateur station on 75 meter LSB.
This
station was later described in detail in R/9 magazine. It used LC
filtering at
10 kHz to generate the SSB signal, followed by conversion to 200 kHz
and 3950
kHz.

1934 - Several amateur SSB stations are in the air using rigs similar
to
W6DEI's

1939 - 68 kHz channel added to Rocky Point system

1946 - R.B. Dome describes "Wide Band Phase Shift Networks" in
Electronics
magazine.

1947 - O. G. "Mike" Villard, W6QYT, puts Stanford University amateur
station
W6YX on 75 meter LSB with a phasing type transmitter using an audio
phase
shift network developed from the Dome article.

The term "SSSC" (Single Sideband Suppressed Carrier) was frequently
used in the early days.

This brings us to the point where SSB began to become common in
amateur
communications. Numerous homebrew transmitters and receive adapters
were described in the amateur literature, followed by manufactured
equipment. Early SSB efforts all used separate receivers and
transmitters - the first SSB transceivers and matched-pair
receiver/transmitter sets for the amateur market did not appear until
the late 1950s (Cosmophone 35, Collins KWM-1 & KWM-2, Collins S-Line,
etc.).

SSB operation concentrated on 75 and 20 meters in the post-WW2 years
because:

- they were the most crowded 'phone allocations
- 40 had no 'phone band, and 15 wasn't a ham band, until the early
1950s.

The main reasons SSB was not more widely adopted by hams in the '30s
were cost and complexity.

In those years (late '40s-early '50s), QST had a regular column called
"On The Air With Single Sideband". There were "SSB Handbooks" for hams
put out by several publishers. And there were gripes that QST was
becoming "too technical" and that ARRL was "forcing SSB down hams'
throats".

The more things change...

73 de Jim, N2EY