FIRST? SINGLE SIDEBAND

[Don Webster]

In a message dated 1/12/2004 8:42:14 PM Central Standard Time,
lmpicard at ALLSTREAM.NET writes:

> Someone stated that some form of synchronous detection was used on these
> wire line or possibly microwave circuits.  Either the low-level carrier
> was filtered and amplified or an analogue circuit somehow locked onto it.
>
> I believe it was stated that either radio or TV network sound was
> carried on these SSB circuits over the long haul.
>

AT&T used SSB on wire line carrier and overseas ship to shore radio at least
as far back as the 30's. A little later,  I think about in the 50's, they used
microwave and coaxial cable multipleplex broadband systems to carry TV and up
to 1800 voice channels. They used a master oscillator in one location,
someplace in the East and used it to sync many other oscillators through out the
country. That way, all of the SSB systems could be phase locked on to each other.
Of course all of this was designed by Bell Labs and made by Western Electric
since they were part of the Bell system before Ma Bell was split up by the
government.

Don

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