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Copyright: 1996 - 2024

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    Kirt Blattenberger,

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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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European Report
August 1949 Radio-Electronics Article

August 1949 Radio-Electronics

August 1949 Radio-Electronics Cover - RF Cafe[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.

It is interesting how over time the common spelling of names of countries change. Sometimes is is merely a difference in the way we in America spell a word versus in Europe; e.g., "color" vs. "colour" and "aluminum" vs. aluminium." In the "European Report" column of this 1949 issue of Radio−Electronics magazine, what we spell as "Romania" today is spelled "Roumania." Aside from that, a fairly uncommon unit of loudness (sound pressure) is mentioned - the "phon" - which is a logarithmic scale of the more familiar linear scale "sone." Note also at the time a person who watches television is a "televiewer" and the thing he/she watches is a "televiser." Finally, a bit about the ever-present battle against electromagnetic interference (aka "noise") both of the natural (QRN) and manmade (QRM) nature. No matter how high in frequency we manage to go, the spectrum will always eventually get crowded.

European Report

European Report, August 1949 Radio-Electronics - RF CafeBy Major Ralph W. Hallows

Radio-Electronics London Correspondent

In Roumania they're talking seriously of loudspeaker reception from a plain crystal set.

No tubes, no transistors; in fact no amplification at all. Just a straight-forward, common crystal detector of the fixed type, connected on one side to thee antenna and on the other to the loudspeaker. When I said talking seriously I meant that no less formidable a publication than the Bulletin of the Roumanian National Technological Research Institute has published an article in which Mr. Matei Marinesco gives accounts of both his investigation of the theory of electromagnetic and other reproducing instruments and of the promising results claimed to have been obtained already in his efforts to evolve a practical crystal-detector-loudspeaker receiver.

It all began like this. Feeling that the radio receiver incorporating tubes and needing "juice" either from electric mains or from relatively expensive batteries could never become really popular in its country districts, where there is little money to spare, the Roumanian Radio Company announced a competition, with large money prizes, for genuine "people's receivers". The conditions were, briefly, that sets should contain no tubes, that they should operate loudspeakers and that they should provide a sound intensity of 30 phons in a room with a content of 50 cubic meters for an input of 100 millivolts.

Getting down to the job, Mr. Marinesco decided that the big snag was not the crystal detector, but the loudspeaker. Those which most of us use are, he finds, sadly inefficient devices, since the ratio of power output to power input works out at between 2 and 6%. Devise a loudspeaker with an output-input ratio of 80% or a bit more and the trick should be done. Mr. Marinesco claims to have evolved loudspeakers with efficiencies up to 85% over fairly wide bands of frequencies, in conjunction with which a simple crystal set fulfills most of the conditions laid down for the competition. Well, here's hoping! What with the transistor and the super-efficient loudspeaker, the amplifying tube may have to look to its laurels.

What the televiewer wants

I was very interested in the data produced not long ago by the American firm, Audience Research, Inc., on what Americans want in the way of televisers and in comparing these with the yearnings, the earnings, the likes, and the dislikes of potential televiewers in Britain. There's no doubt at all about what our ordinary man and woman regard as essential in a televisor. First and foremost, they simply won't have any set which gives a picture with an area less than 65 square inches. And that means a 10-inch C-R tube. At one time or another this manufacturer or that has tried to popularize a low-priced set using a 4-inch, 6-inch, or 8-inch C-R tube and the result has invariably been something very like a complete flop. Even if a televiser gives the clearest of images of smaller size than about 65 square inches, the ordinary viewer just won't have it in the house.

Next, our folk won't buy the televiser that does not also reproduce the accompanying sounds. The main reason for this is that few indeed of our domestic radio receivers can tune in the sound channel of the television broadcasts.  

Price seems to be a secondary consideration. So long as its cost is not outrageously high, a good televiser sells rather more quickly than its makers can produce it. That is due to some extent to prevailing conditions. We are still on short commons as regards food and our shops (owing to the urgent necessity of exporting all we can in order to pay our way) are still not too well stocked with consumer goods. Hence, there aren't many things on which people can spend what money they have left after paying living expenses and taxes. Televisers can be bought on the installment system and, provided the installments are within their means, people buy them in large quantities.

From the A. R. I. report I see that televiser prices are, on the average, round about the $400 mark in the U.S. (The A. R. I. report is based on U.S. TV prices in effect last fall. - Editor) Now, that does surprise me. On ordinary broadcast radios American prices are far below British. A small 4-tube radio receiver costs at least twice as much here as it does in the States. (I'm leaving purchase tax out of consideration, since it varies from time to time and has, in any event, nothing to do with the efficiency or otherwise of mass-production methods). But British prices for televisers - remember I'm speaking of sound-and-vision sets with at least 10-inch C-R tubes - seem to be a great deal less than yours. Were I intending to go out tomorrow to buy a TV receiver of the kind mentioned, I'd find two or three types below the $200 mark and quite a wide selection at under $300. For $750 I could buy a good-looking combination all-wave radio-phonograph-televiser with a 12- inch-diameter cathode-ray viewing tube and all the trimmings.

The war on interference

You may recall that I've told you already how we in Britain are tackling the problem of man-made interference with radio and television reception by making it illegal to operate an unsuppressed factory machine, domestic electrical appliance, or automobile. In Switzerland they're dealing with some of the main causes of interference in another way. Switzerland is, in proportion to its size and its population, perhaps the most completely electrified country in the world today. Thanks to its vast resources of waterpower, even small villages and outlying farms have electric mains supplies. No steam locomotive runs on its railways and it has a vast mileage of electric street-car systems. Some of the street cars operate over interurban systems of considerable extent. With cheap electric power available everywhere you can imagine that radio listeners (there are no televiewers yet) complain bitterly of the effects of man-made static. They have to pay for licenses to use radios and they're not a bit pleased when a fine selection of "noises offstage" makes a classical concert sound like a feature program concerning a large boiler factory.

The license fees are collected by the government Posts and Telegraphs Department, which has recently decided to spend a considerable percentage of this income on static suppression at source. To accomplish this will certainly cost a tidy sum, for, to take transport alone, both the railways and the street car systems use overhead conducting wires with spring-loaded sweep contactors on locomotives and cars. At every joint in the overhead wires the travelling contactors are liable to jump, producing sparks and radiation of the kind which shock-excites antennas over a considerable area. The problem is a pretty big one, you'll agree, and the Swiss are to be congratulated on getting down to it in this practical way.

 

 

Posted September 27, 2021

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