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August 1961 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.
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 The
old adage about history repeating itself is borne out once again in this "News
Briefs" feature in a 1961 issue of Radio-Electronics magazine. When cellphones, Wi-Fi and
Bluetooth enabled portable computers came about, commercial airlines prohibited
turning them on while in flight due to concerns that unintentional radiation
emanating from the devices might interfere with navigation and communications
systems, thereby posing a safety threat. In 1961, the FCC (Federal
Communications Commission) imposed a ban on in-flight FM radio usage. In other
news, CBS announced it was phasing out production of vacuum tubes, as
transistors were dominating the industry. At the same time,
Amperex boasted of a
new type cathode which could heat to operating temperature in a tenth of a
second (old guys like me remember waiting for the radio and TV to heat up before
becoming functional). Anyone else remember having to rush to turn the volume
down after having turned it up before the set fully warmed up?
New Briefs:
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9/68
News Briefs
 GE, Zenith Start Stereo FM
Starting at the earliest moment permitted by law, 0001 Daylight Saving Time,
June 1, stations WGFM, Schenectady, N.Y., and WEFM, Chicago, Ill., inaugurated FM
stereo broadcasting under the FCC's new rule permitting multiplex stereo service.
General Electric, owners of WGFM, claim the "first," since June 1 began an hour
earlier in Schenectady, in the Eastern time zone. Thus Zenith's WEFM, starting at
the same clock time, was actually an hour later, WGFM initiated a regular schedule
of stereo broadcasting with 20 hours a week programmed for the first few weeks at
least. WEFM did not immediately announce a stereo schedule, but is expected to devote
a considerable portion of its time to that type of broadcasting.
New Cathode Heats in 1/10 Second
Adopting a filamentary cathode for fast warmup, Amperex Corp. claims the fastest-heating
cathode ever produced. It delivers full output power in 100 milliseconds. The new
cathode consists of a rectangular frame across whose length a number of very fine
wires are strung parallel to each other like the strings on a harp, for which reason
it is called the harp cathode. The large number of fine wires gives the emitting
element a high surface-to-volume ratio, resulting in fast warmup and thermal equilibrium.
The large number of parallel paths makes low voltages feasible; the 1.6 volts used
on this tube is the closest approximation to a unipotential cathode yet achieved
in a filament. Current in the present type is 3.2 amps. The multiple-wire cathode
also reduces inductance and cuts hum.
No Air-Borne FM Receivers
The Federal Aviation Agency has forbidden the use of portable FM receivers in
aircraft. Tests indicate that the local oscillator of some FM receivers generated
signals that were picked up in the aircraft navigation band. This, according to
the FAA, tripped the "red flag" alarm that indicates that the fixed-tune navigation
receiver is not working properly. To avoid confusion or the possibility that interference
not heavy enough to trip the alarm might result in falsifying the information supplied
by the receiver, the ban was established.
The FAA tested a number of electronic devices often operated in aircraft, including
portable AM radios, dictating machines and recorders, and found that only the FM
receiver was a probable producer of interference.
Transistors Will Replace ... ?
Two well known companies, Philco's Lansdale Div. and CBS Electronics, announce
that they are getting out of the entertainment tube business. The use of receiving
tubes by original equipment manufacturers has declined 31% since 1955, reported Wm, J. Peltz of the Lansdale Div., and the plant has been producing 80% transistors,
10% cathode-ray tubes and only 10% receiving tubes.
CBS Electronics reported that it was closing its factories at Danvers and Newburyport,
Mass. Raytheon is taking over the inventory of CBS tubes and continuing to service
CBS distributors and their customers. The closing of the CBS tube plants marks the
end of the oldest tube operations in the field, that of Hytron, who started making
tubes in 1921 and merged with CBS 10 years ago.
Education Out of the Air
Stratovision - first advocated and described by Westinghouse in 1945 - has been
put into successful operation over parts of Illinois, Indiana, Michigan, Ohio, Kentucky
and Wisconsin. Educational programs on channels 72 and 76 are broadcast
from planes in flight. The planes fly 23,000 feet high over Montpelier, Ind.,
and their service area is within a radius of 200 miles from that city. Actually,
good pictures have been received over greater distances.
According to Blonder - Tongue Labs, which installed some of the school master
antennas used in the system, outstanding educators are being recruited in a "talent
search" to obtain instructors when the broadcasts go on a regularly scheduled basis
at the beginning of the school year in September. As budgets are laid down at present,
teachers will be allowed an expenditure of up to $50 per lesson, 12 to 20 hours
in preparation time, and the services of artists and designers.
Posted September 17, 2024
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