August 1960 Radio-Electronics
[Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
communications via satellite were a few years off when Pacific Scatter
Communications System (PSCS) was established as a network of microwave radio
relays that spanned the Pacific Ocean during the Cold War era. It was established by
the U.S. in the late 1950s as a means of maintaining secure communications with
its military and diplomatic installations in Asia, particularly in Japan and
South Korea. PSCS consisted of a series of shortwave and microwave relay stations located
on islands throughout the Pacific, including Hawaii, Guam, Saipan, Okinawa, and,
as reported in this 1960 issue of Radio−Electronics magazine, Wake
Island. The system was designed to be highly resilient, with redundant
communication paths and backup power supplies to ensure that communication could
be maintained even in the event of a nuclear attack. It played a critical role
in supporting military operations during the Vietnam War and in maintaining
diplomatic relations with allies in Asia. The PSCS was eventually superseded by
more advanced satellite communication systems in the 1980s. Also in the news,
General Motors was experimenting with self-driving cars, a concept that more
than six decades later, is still not implemented in everyday life. Hotels were
working hard to get TVs in every room, being at 81% penetration as of 1960.
New Briefs: 11/1957
| 8/1958 |
Scatter Communications For Armed Forces
A 6500-mile communications system designed to give the Pacific area virtually
trouble-free communications has gone into operation. Built for use by the Armed
Forces, the Pacific Scatter Communications System uses advanced ionospheric and
tropospheric scatter propagation to give better than 99% reliability. Unlike most
scatter systems, parabolic antennas are not used. Instead, 200- and 400-foot antenna
arrays composed of stacked dual-frequency corner reflectors handle the signals rather
than the more usual dishes. The ones shown in the photo are at the Wake Island station.
The scatter technique beams radio signals at the ionosphere or the troposphere,
to bounce back to earth in a scattered fashion. The signals are not broken up. They
are only scattered. Diversity reception is used. One receiver will pick up the clearest
signal. If it should fade, another receiver will pick up another "branch" of the
same signal without a lapse. In this way a steady flow of intelligible trouble-free
information is insured.
The system, which was built by the Army and Page Communications Engineers, permits
reliable communications between a transmitter and receiver 600 to 1,200 miles apart,
even under conditions which disrupt normal long-distance radio signals.
Highways Come a Step Closer
A full-size electronic highway has had its first public showing. Demonstrated
by RCA in cooperation with General Motors, two specially equipped cars were guided
automatically around a test track at RCA's David Sarnoff Research Center in Princeton,
N. J. Acceleration, braking and maintaining a safe distance between vehicles were
all automatically controlled by electronic signals from the road. (Radio-Electronics
described this system in an article by Vladimir K. Zworykin, "Electronics Guides
Your Car". This story in the April, 1959, issue was one of a series on electronic
During the tests, circuits built into the road were used to inform the cars'
"drivers" of simulated road intersections, service areas or hazardous conditions
ahead. This automatic electronic road can be used by electronically equipped and
by non-equipped autos simultaneously. Both produce warning signals. The difference
is that the equipped car uses its complement of electronic gear (see photo) to automatically
react to electronic signals. The driver of the standard car must keep track of roadside
signs and lights that warn him of cars head and other possible dangers.
A new production technique makes it possible to build switching transistors that
work 10 times faster than existing ones. Units made by the new process are called
epitaxial diffused transistors. This process forms an extremely thin, lightly doped
collector region which is grown on a heavily doped low-resistance layer. The lightly
doped area has a high resistance and, by keeping this layer thin, collector resistance
is reduced and switching time with it. Epitaxial diffusion makes possible a high-resistance
collector layer that is as much as 30 times as thin as usual.
The epitaxial techniques, developed by Bell Telephone Laboratories, can be added
to existing diffused-base transistor production lines with little trouble. The process
is simple. Single crystal wafers of heavily doped material are cut and polished.
Then a thin film (about 0.1 mil) of a lightly doped material is deposited on the
wafer to provide the desired collector region. From this point on, standard diffused
base techniques are used. The diagrams show the difference in the construction of
standard (Fig. 1) and epitaxial (Fig. 2) switching transistors.
Methods of growing single crystals of gallium phosphide, a transparent semiconductor
material, are being developed at Bell Telephone Laboratories. The properties of
this substance are also being investigated. Since the material is transparent, it
is possible to observe visually the differences which take place under varying conditions
of doping and electron density. The largest single crystals produced so far measure
3/4 inch long by 1/4 inch square. The experimental work is aimed at a general understanding
of semiconductors and junctions.
Motels Like TV
A nation-wide survey of TV sets, antennas and service revealed that 15,660 out
of 19,337 motel rooms have TV sets, according to American Motel Magazine. Most of
those who do not have sets installed plan to get them within the next year.
Motel owners indicated that the greatest problem related to room TV installations
is not reception or servicing, but instead is the misuse, mishandling and tampering
with sets by guests. They rated sturdiness as one of the lesser problems along with
theft and antenna trouble. The owners also showed a marked preference for master
antenna systems over indoor antennas and individual room systems.
The discovery of two strong new piezoelectric compounds -
zinc oxide and
sulfide - has been reported by Dr. A. R. Hutson of Bell Telephone Laboratories.
The degree of piezoelectricity of zinc oxide is about four times as great as that
of quartz while that of cadmium sulfide is about twice as great.
Both zinc oxide (ZnO) and cadmium sulfide (CdS) are n-type semiconductors with the ZnO having a room temperature resistivity of less than 10^3 ohm−cm. This relatively
low resistivity effectively shorts out all experimental evidence of piezoelectricity
unless the ZnO is first doped with an impurity (lithium) that accepts the excess
electrons (which contribute to the conductivity). After doping, the resistivity
of the ZnO was raised to 10^12 ohm−cm.
Posted March 15, 2023