Radio-Electronics Monthly Review
September 1947 Radio-Craft

September 1947 Radio-Craft [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Craft, published 1929 - 1953. All copyrights are hereby acknowledged.

The "Monthly Review" column appearing in Radio-Craft magazine was an assorted collection of news tidbits about electronics and communications industry happenings, similar to contemporary magazines. Looking back to 1947, the world was hopeful about the future as World War II was finally over and even the loser countries were focusing on how their societies would be shaped by technology and lessons learned in the preceding seven to ten years (depending on when a country entered the war). Two items here are particularly interesting because they refer to ongoing research into large screen televisions and video phones (aka "televisers"). Large screens at the time meant either much bigger cathode ray tubes (CRTs) or projection systems - both of which came to fruition in the 1960s and 1980s, respectively. Plasma screens, then LCD and finally LED screens mark the eventual evolution. Holographic displays as predicted in the 1970s have still not been realized. We have had video phone capability for a decade and a half with the incarnation of camera-equipped smartphones. Even so, there is not a whole lot of casual person-to-person televising going on. Dick Tracy watches still are not the norm (even the iWatch attempt is lame), which we were pretty much promised to us by the year 2000.

Items Interesting to the Radio Technician

Proximity Fuzes which were operated by light instead of radio waves were used on rockets during the, war, it was disclosed last month by Frank A. Zupa of Bell Telephone Laboratories. The "seeing-eye" fuze functioned when proximity to the target cut off part of the light which normally reached it. Essential parts of the device were a ring-shaped lens built into its nose, a photocell, an amplifier, and a selective switch. When the rocket was fired, the selective switch armed the fuze by throwing the amplifier into circuit.

While the rocket was in flight, daylight entering through the lens and striking the photocell maintained a certain level of current that did not activate the detonating mechanism. As the missile approached its target, however, some of the light was cut off by the target itself, and the resulting change in current level served to setoff the explosive charge.

Apparently this type of fuze was useful only during the day, and would not be useful in conditions of twilight or darkness.

Pay-As-You-See television was pro-posed last month by Commander E. F. McDonald, president of Zenith Radio Corp., as a means of solving the economic problems of television broadcasting.

According to the plan proposed by McDonald, scrambled television signals would be sent through the air to the receiver in the usual fashion. Special unscrambling signals would be sent over the telephone wires, to which the set would be connected. To receive the program in intelligible form, the user would call the telephone operator and ask for "Phone-Vision." Payment for the television service could then be made through the telephone company, much as for a long-distance call if arrangements can be made with the 'phone companies.

The subscriber's telephone could be used for ordinary calls while receiving a program, without interference either to the program or telephone conversation.

Commander McDonald states that experimental transmissions have already been made, and that technically the system is quite successful. Telephone officials point out, however, that there might be legal obstacles, at least in some states.

Citizen's Radio is about to come out of the blueprint stage, a last month's Science Service report states. Fifty manufacturers and experimenters are already talking on the allotted 460-470 megacycle band under experimental licenses. About 500 small portables are already in use by police, firemen, foresters, geologists, and motion picture producers.

Radio engineering advances made during the war are helping to speed the day when such personal radio-telephone sets can be bought and when the FCC will allow them to be used. Printed circuits, in which metallic paint on plastic or ceramic plates replaces conventional soldered wires, will make the new sets lighter and smaller. Miniature tubes, such as used in the famous wartime proximity fuzes, will in some cases replace 3 or more tubes of conventional prewar radio sets.

Manufacturers' are not yet ready to guess at what these Citizen's Radio Service sets will cost. Probably they will be in the price class with the better kind of living-room radio.

You can't yet apply for a license to operate a citizen's radio because the rules and regulations are not yet drafted by the FCC. The new service probably will not be legalized before early next year.

Radar terrain-clearance indicators will be required on all air lines for a 2-year experimental period beginning January 1, 1948, the Civil Aeronautics Board indicated last month.

Several devices are competing for the selection as approved equipment, among them being the new Hughes lightweight clearance indicator, the light Army radar described in Radio-Craft last March, and a similar radar developed jointly by the Navy and American Airlines.

Advice to young scientists not to take too much for granted because it is backed by authority was given by Dr. Harvey C. Rentschler on his retirement as director of Westinghouse lamp and electronic tube research last month.

"The best research engineers I have known," he said, "have been those whose minds are open to conviction and who are able to make their own decisions. Just because something is stated as a fact in the scientific literature is no positive proof that it is a truth. Formulas, equations and rules were made to be challenged and exist only because someone challenged former rules.

Large-Screen television is about to make its commercial debut, a last month's report issued jointly by RCA and Warner Brothers Pictures states.

The large-screen video will be introduced in a Broadway theater by Warners and may also be piped into other theaters operated by the company. Preliminary tests made by Warners and RCA indicate that spot news and special events coverage lend themselves to theater presentation, and the television feature will be presented in conjunction with other newsreel subjects.

Another large-screen commercial television installation is proposed at the Monte Carlo Swimming Pool at Asbury Park, N. J. A screen 6 x 8 feet is to be used.

The screen is said to offer a new form of direct projection from the face of the tube to a brighter-type screen. The life-size projection will give its audience day and night baseball, boxing and wrestling, as well as any other important events televised in course of the season.

Radio Items of the Month

Ultimate in radio service was offered recently by the Radio Center of Yonkers, N. Y. An advertisement of that company carried the following:

"ATTENTION

To the Thieves Who Stole My 22 Radios

Remember, We Guarantee Our Radios Whether You Buy or Steal Them.

The Management"

Facsimile transmission capable of sending a million words a minute was revealed last month by Niles Trammel, president of NBC. The equipment, under development by RCA, combines present facsimile and television techniques.

Deafness tester which uses a 2-toned whine to tire normal ears and temporarily dull their receptivity was reported last month by Dr. Mark B. Gardiner of the Bell Telephone Co. The test is designed to determine the type rather than the extent of deafness.

Television equipment is being constructed to be used underwater at the site of last year's Bikini atom-bomb explosion. It will be used in a scientific survey of the results of the underwater bomb explosion.

Diathermy equipment which causes radio interference is no longer permitted to operate in the United States. The owner of any such equipment must either modify it to comply with FCC regulations or cease operating it altogether.

Television broadcasts now cover territory inhabited by 25,000,000 people.

Television which permits the parties in a telephone conversation to see each other was reported from Russia last month. The face of the person at either end of the line is shown on a small screen. The image is picked up by a lens beside the video screen.

The device is the invention of I. P. Zakharov, a staff worker of the USSR Television Research Institute. He calls his invention a videotelephone. A number of the devices installed at the Institute are reported to be working satisfactorily.

If successful, the videotelephone will fill a long-felt need, as some of the very earliest concepts of televisors were of instruments which would permit adding vision to sound in ordinary telephone conversation.

Australian reception of American FM stations was not due to improved or "new" receiving apparatus, as early newspaper reports implied.

Queried on the subject, Radio-Craft's Australian correspondent, John W. Straede, states: "I spoke to Mr. Graham, who with his brother runs a radio shop in Melbourne. He tells me the radio is a standard FM-AM receiver with nothing new or startling, and that reception on the longer wavelength FM bands (30 to 40 mc) is fairly consistent in the summer.

"The stations received are mostly police and emergency services such as fire brigades."

A Perfect Robot has been the dream of scientists throughout the ages. This dream may be a little nearer to realization as a result of progress with electronic "thinking machines." At least some of the men who helped design and build these machines think so.

Says Professor Norbert Weiner of the Massachusetts Institute of Technology: "I defy you to describe a capacity of the human brain which I cannot duplicate with electronic devices." Professor Edwin G. Boring, director of Harvard's psychological laboratory, is willing to go even further: "... it should require only a matter of time, patience and continued support from some foundation," he says, "to design a bright and attractive dinner companion or eventually even the perfect professor of psychology."

Vacuum Leaks may now be detected by a new ionization gage tube which permits one gas to pass while holding back all others, according to a release issued last month by RCA. The new tube, RCA1945, is sensitive to hydrogen only. It features a palladium plate which, when hot, is porous to hydrogen but acts as a vacuum-tight barrier to all other gases and vapors. In operation, the tube is connected into a vacuum enclosure or system to be checked for leaks. A tiny jet of hydrogen is then played over the outside areas of the suspected system. Any leaks will suck in the hydrogen which then runs down to the tube, passing through the palladium plate and causing an increase in the ion current inside the tube. This increase in current is amplified and indicated on a microammeter. Tiny leaks, so small that molecules of air barely pass through them, can be detected by the tube, which is sensitive enough to detect an increase in hydrogen pressure of less than 0.0000001 mm of mercury.

Under the plan, television receivers are delivered, installed, and picked up anywhere in the metropolitan area.

FM Production is on the increase, Arthur Freed, treasurer of the FM Association, reported last month. Between 15 and 20 manufacturers who have produced only AM receivers up to the present expect to start manufacture of FM sets before the end of the year, he said.

According to the same report, more than 700 FM stations will be in operation before the end of the year, and 80% of the country's population will be within range of at least one FM station.

Posted August 5, 2020