August 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.
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.
By Major Ralph W. Hallows
Radio-Electronics London Correspondent
In Roumania they're talking seriously of loudspeaker reception from a plain crystal
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
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