November 1949 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.
"The Radio Month" news
column from the November 1949 issue of Radio−Electronics magazine contained
much interesting information. At the top of the list was an announcement that an
all-electronics system for color television implementation had been presented to
the Federal Communications Commission (FCC). It was one of three such systems vying
for official adoption as an industry standard.
CBS (Columbia Broadcasting System),
CTI (Color Television,
Inc.), and RCA (Radio Corporation
of America) were in stiff competition. Here is a January 1951
article describing the three systems. Ultimately, the NTSC forged its own standard
that incorporated an all-electronic system that was also backward-compatible with
the existing black and white (B&W) system. Also included was information about
the first Philadelphia Radio Service Men's Association (PRSMA) meeting. It was sort
of an IEEE for electronic service technicians. 52 display booths were set up to
woo the 500+ per day technicians in attendance.
The Radio Month
Top - Dave Krantz opens a session of the Philadelphia Radio Service
Men's Association (PRSMA) convention. Bottom - Service technicians visit the exhibitors'
Color Television using all-electronic methods and utilizing
only the present 6-mc channel was demonstrated to the FCC last month by RCA. Resulting
from new and basic technical developments, the system permits color transmissions
to be sent over existing, unmodified transmitters and to be received in black and
white on present receivers. Receivers built for color reception or equipped with
a color converter can receive programs either in color or in monochrome so that
stations need broadcast in color only shows suited for it. The system is all-electronic,
with no moving parts.
Dr. E. W. Engstrom, vice-president in charge of research at RCA Laboratories,
who prepared the engineering statement for the FCC, said that there is no degradation
in picture quality, whether images are received in color or monochrome, on special
receivers or on standard ones. No receiver adjustments are required when stations
switch from color to black-and-white or vice versa.
The new color system is based primarily on a time multiplexing system, by which
three camera signals are successively sampled at high speed. Each signal carries
picture information of one of the three primary colors. The signals are combined
and passed to the transmitter after filtering, containing no components of higher
frequency than 4 mc.
At the receiver the r.f., pix and sound i.f., second detector, and sound circuits
are standard. The video signals are separated into their .color components and fed
to three cathode-ray tubes, one with red phosphor, one with green, and one with
blue. The three images are projected on a screen in register so that in the final
picture each color shows up in its correct value.
Citizens Radio Corp., holder of the patents on the first transceiver
to be approved by the FCC for use in the citizens band, was sold last month to Stewart-Warner
Corp. Al Gross, inventor of the transceiver, will continue as chief engineer. Large-scale
production is scheduled to begin soon; the firm has been flooded with orders.
Service Technicians Hold Convention (see photo above)
Radio service history was made in the three-day convention and exhibition staged
in Philadelphia on September 18, 19, and 20 by the Philadelphia Radio Service Men's
Association (PRSMA). Held for the purpose of publicizing and promoting Pennsylvania's
Preventive Maintenance Month in October, it was the first full-scale professional
combined convention and show ever held by radio service technicians. More than 1,700
persons registered for the first evening of the convention, which began at 5 p.m.
on the 18th and closed at 4 p.m. on the 20th. The evening of the 19th, attendance
so greatly surpassed that of the first evening that it was necessary to turn several
hundred people away. About 500 technicians were in constant attendance at the daytime
sessions on Monday and Tuesday.
Fifty-two booths were occupied by companies whose products are interesting to
the service technician and by radio magazines which deal with service problems.
Exhibits ranged through the whole gamut of radio and television test equipment and
accessories from antenna towers to technical books and service data.
Booths and technical sessions received almost equal attention from the attending
service technicians. The latter included talks on the technician's technical and
business problems and demonstrations of television servicing and trouble shooting,
backed up by ample equipment. (Both the Dynamic Demonstrator operated by John Meagher
of RCA and the oscilloscope and projection equipment used to assist the talk by
Carl Quirk of Du Mont practically filled the stage.)
John Rider, Al Steinberg, and A. T. Alexander covered the general situation.
Mr. Steinberg covered especially the relations among service technicians, distributor's,
and manufacturers. Mr. Alexander spoke on the problems of servicing and of service
training from the manufacturers' viewpoint on a national scale.
Other papers covered television serving and maintenance from the antenna to the
picture tube, with special attention to front ends, alignment, electronic antennas,
multiple reception, and test equipment. The papers were exceptionally well received,
and the hall was crowded during everyone of the lectures and demonstrations.
The convention was presided over by Dave Krantz, president of PRSMA, who lost
no opportunity to drive home the importance of the Preventive Maintenance Month
campaign to the service technicians of Pennsylvania. Pointing out that the example
of Harrisburg last winter proved that such a campaign could increase repair business
as much as 25%, he urged that every set owner ill the state be given an opportunity
to have his set checked over to assure continued good performance and to avoid possible
major repairs which may be necessary later.
Members of PRSMA cooperated to do the organizational, executive, and menial labor
needed to keep the convention running smoothly, and it is to their efforts that
the great success of the undertaking is due.
Color and Monochrome (B&W) Television
Posted November 29, 2021