Billed at the time as the longest microwave relay system in the
world, this report on Bell Telephone Systems' transcontinental installation
came just a month after being put into commercial service. At a
cost of $40 million ($650 million in 2015
BLS Inflation Calculator), the system relays telephone
calls and radio and video program material along a chain of 107
microwave towers, spaced approximately 30 miles apart. It was a
big deal to be able to watch a TV show from New York City in Los
Angeles, and vice versa; we take worldwide broadcasts for granted
Bell System Opens Transcontinental Radio-Relay
By William Alberts
Original commercial service provides two TV channels - one east
and one west. Other channels will be added as needed.
Air view of Long Lines radio-relay station at
Mt. Rose, Nevada. At an elevation of 10,000 ft., this is highest
station in system.
By the time this issue reaches our readers coast-to-coast commercial
television will be a reality. This video link has been made possible
by the completion of the new microwave radio-relay built by the
Long Lines Department of the American Telephone &; Telegraph
Radio-relay station at Creston, Wyoming, showing
both the receiving and sending microwave antennas at two different
This new project is the longest microwave system in the world
and is the product of years of engineering effort and cooperation
by the development, manufacturing, and operating units of the Bell
The relay was put into temporary service on September 4th to
carry the ceremonies in connection with the Japanese Peace Treaty
Conference held in San Francisco. Built in about three years at
a cost of $40,000,000, the system relays telephone calls and radio
and video program material along a chain of 107 microwave towers,
spaced approximately 30 miles apart.
The vast distances, together with the large number of radio channels
required, posed many serious problems for the Bell Telephone Laboratories.
Three new developments provided the answers. First, a new electronic
tube was developed which gave outstanding performance at the super
high frequencies. Second, the Laboratories came up with a new improved
metal lens which would handle thousands of simultaneous telephone
calls. A unique system of filters, representing an entirely new
contribution to the field of communications, was developed. All
of this electronic equipment was built and installed by the Western
Electric Company, the manufacturing unit of the Bell System.
Cutaway view of a typical concrete station in
Long Lines transcontinental radio-relay system just put into service.
Operating in the 4000 mc. range, the new relay system employs
amplifying equipment at each station to boost the signal 10,000,000
times before retransmitting.
Initially, the system will provide one east-to-west channel for
television. The west-to-east channel is expected to be in service
within a few weeks.
One of the concrete stations on the radio-relay
route between Chicago and Des Moines.
The story of how this vast system came into being is one worthy
of the days of pioneering. In locating and constructing the 107
towers comprising the system, the engineers encountered every type
of terrain. The first step in determining a tower site involved
the study of topographical maps and then an on-the-spot inspection
to determine clear paths between prospective stations and the detection
of all reflective surfaces, such as water or flat lands, that might
impair the signal. To insure best construction conditions and ease
of maintenance, the accessibility of the site to all-weather roads
had to be considered.
Next, sites about 25 miles apart were tentatively selected with
alternate sites chosen in each instance. The land for each station
was then optioned and field tests were held to determine the transmission
and reception quality of that particular location.
Following the preliminary tests, borings were made and soil samples
taken to determine the type and depth of foundation necessary for
each station. In addition to securing the necessary FCC authorization,
clearance had to be obtained from the CAA because of the towers
and their rulings heeded as to outside lighting for the towers.
The 200 foot steel tower at Salt Lake City Junction
overlooking Salt Lake City and Great Salt Lake. This is one of the
107 stations on the transcontinental relay system.
Depending on the location of the stations, the towers range in
height from 40 to 200 feet. In many cases they are concrete buildings
with space on the ground floor for a gasoline engine to generate
emergency power in case of power line failure.
The second and third floors of the stations house the storage
batteries and associated power equipment. The amplifying and testing
gear is housed on the fourth floor while the top of each station
carries the horn-shaped directional antennas.
Unusual view of the Cisco-Butte, California station
of the transcontinental relay system. This station is located in
a valley high in the Sierra-Nevada mountain range.
All-in-all this vast engineering feat represents an important
addition to the country's communications facilities for both peace
and war, provides coast-to-coast network facilities for the transmission
of television programs, and opens up thousands of new channels for
long distance phone service.
With the completion of this new microwave relay system the country
now has seven telephone highways crossing the continent.
Posted December 24, 2015