Two major radio events were covered
in this 1954 issue of Radio & TV News magazine's monthly "Spot Radio
News" column - the rapid advance of microwave technology for building out high capacity
voice and television transmission systems, and the ever-increasing number of new
TV station operation license grants since the ending of the Federal Communications
moratorium in 1952. In 1944, the FCC stopped issuing broadcast permits due to
serious unforeseen interference from co-location interference issues as post-war
households enthusiastically adopted TV. Unlike today's microwave relay networks,
in the 1950s most systems were still analog in nature. Coaxial cable installations
were good, but use over extra long distances and in difficult to access areas limited
their applicability. Line-of-sight limitations between relay towers required building
more sites than might otherwise be required, but the advantage was significantly
narrower beamwidths that allow more channels in a give volume of space, and the
characteristic gain of directional antennas permitted lower power at the transmitted
and and better reception at the receiver end.
Presenting latest information on the Radio Industry
By Radio & Television News
Microwaves, the new work-horse of radio now being sought by an increasing number
of radio and TV broadcasters and an unending list of public and private agencies,
is now on trial in Washington.
The tremendous demand for these upstairs channels (890 to 13,000 mega-cycles)
has jammed the Commission's hearing schedule and dictated a fact-finding session
that will provide a pattern for, the future use and requirements of the microwave
A variety of advantages has been responsible for the rising popularity of the
microwave signals. They can be directed to any selected spot within view of the
transmitter and, by means of successive repeater stations, relayed over added distances.
Microwave communications can be in the form of voice and telegraph correspondence,
also teletype, facsimile, and TV-relay services. Further, microwave facilities permit
push-button observation of industrial and other business operations, and remote
control of device's throughout a system. By methods known as multiplexing, many
messages or functions may be handled simultaneously over a single microwave channel.
Because of their position in the radio spectrum,
microwaves are not affected in the same way by weather and man-made interference
as are radio services operating on lower frequencies. In turn, their straight-line
directivity permits the same channel to be used by parallel systems transmitting
different kinds of information. Microwave systems are usually more economical to
install and maintain, as compared to wire lines, where a substantial number of communication
channels are required, or a single broad communication channel, such as television,
is involved. Also, since the transmitter energy may be concentrated and pointed,
microwave requires comparatively little transmitter power.
A major part of the nationwide TV program network operates over microwave systems
provided by the telephone companies. In other cases, where such facilities are not
available from the telephone companies, individual TV stations have installed their
own private microwave relay systems.
Also serving TV are the microwave links which carry programs from the local city
studios of a broadcaster to the distant transmitter site of the TV broadcast station.
Portable and mobile microwave transmitters make it possible to pick up news, sports,
and other events outside of the regular studios and deliver them to the transmitter.
Microwave adjuncts for TV broadcasting, other than intercity circuits operated
by common carriers, operate in bands at 2000, 7000, and 13,000 megacycles.
Posted March 30, 2020