Eighty years ago, the beginner couldn’t go wrong with this one-tube radio kit from the 1940 Lafayette catalog. For $3.95 (plus tube, batteries, and headphones) he or she could put together this set and pull in broadcast stations, both local and distant. And for only 98 cents more, they could buy coils to cover four shortwave bands from 16 to 200 meters.
When this issue of National Radio News, August-September 1945, went to press, the war was still raging in the Pacific. But the end was in sight, and despite the cynicism of skeptics, the editors of the magazine knew that television’s role in the postwar electronic era was a foregone conclusion, “witness the rapt attention of these comely lasses as they view the screen of the General Electric receiver.”
If Junior is looking for a spectacular science fair project that can be built at little expense, but still uses a slightly dangerous chemical, he can’t go wrong building this real submarine, according to plans contained in the August 1940 issue of Popular Science.
School will eventually reopen, so your young submariners can take advantage of their summer vacation to build and test the craft, which can be made out of scraps of sheet metal and tin cans. Soldering is required, but kids naturally enjoy working with molten lead. When school reopens and the science fair is on, the submarine can be used for a variety of scientific experiments involving buoyancy, propulsion, or chemical reactions. The teacher has probably seen old movies with miners wearing headlamps, but this will probably be their first exposure to the actual chemical used. A blue ribbon is almost guaranteed.
These lucky youngsters have probably been drawing Social Security for about a decade, but in 1950, they were tuning in a favorite program on this attractive five-tube radio put together by their dad and big brother. The internal circuitry was a typical “All American Five” superhet, with a tube lineup of 12SA7, 12SK7, 12SQ7, 50L6, and 35Z5 rectifier. Since this was an AC-DC set, the article cautioned that the screws holding the chassis to the wooden case should be covered up for safety.
The cabinet is designed to resemble a circus wagon. The front is carefully painted with red and white enamel paint, with wooden dowels making the cage. Then, after the paint has dried, animal decals are applied.
The plans appeared in the August 1950 issue of Popular Mechanics.
Sixty years ago this month, the August 1960 issue of Popular Electronics showed how to make the holy grail of crystal sets: a crystal set capable of loudspeaker operation.
The author, Walter B. Ford, reported good reception, including loudspeaker volume on strong local stations. The set relied upon two secrets. First of all, it had two tuned circuits in the front end for maximum selectivity. It also used two 1N34A diodes in a voltage-doubling circuit. For weaker stations, headphones could be used, or it could be used as an excellent AM tuner for an external amplifier. But for the strong stations, it would drive the speaker, with no power source other than the received signal.
The ferrite loopsticks might be hard to find these days, although with a ferrite rod, you should be able to make your own. More information can be found at this link. More hints on sourcing the parts can be found at my crystal set parts page.
Today marks the 75th anniversary of the bombing of Nagasaki on August 9, 1945. The attack is reported here in that day’s issue of the Chicago Tribune. If the Japanese needed further convincing to surrender, that day also brought news that the Soviets had declared war on Japan and were attacking Japanese forces in Manchuria.
The video below is a radio broadcast that day by President Truman promising that the bombings would continue until the Japanese surrendered. The war would be over in a few days.
This photo isn’t as sinister as it looks, and nothing untoward is going to happen to the gentleman at the left. The photo is from the August 1945 issue of Popular Mechanics, and these gentlemen are dealing with wartime parts shortages. They’re doing an emergency repair on this set, and need some way to power the filaments of the six-volt tubes. The filament transformer they need is a wartime priority item, so they instead wired the filaments in series and used a 40-watt light bulb as a dropping resistor.
The picture is accompanied by a table showing the resistance of common lamps.
The young man shown here is probably getting ready to collect his first Social Security check, but fifty years ago, he undoubtedly took home the blue ribbon at the 1970 Science Fair. His project was shown in the August-September 1970 issue of Science and Electronics. According to the magazine, the project would show off knowledge and understanding, but would also require dexterity with tools.
The project was a moving-coil ammeter, not unlike a commercially made meter movement. While the magazine didn’t use the moniker, this type of meter is also commonly known as a d’Arsonval meter movement, after Jacques-Arsène d’Arsonval. For less advanced students, the article referred back to construction articles for some more primitive meters, such as the hot-wire ammeter we previously profiled. Most of the meter’s mechanical parts were made of wood, so the project required some expertise in the wood shop. The form for the moving coil was made with balsa wood, whose light weight ensured a sensitive movement.
The finished product could be accurately calibrated by using a commercial VOM, a battery, and a potentiometer. Current readings were noted on the commercial meter, and then marked on the face of the homemade meter.
According to the article, if the builder used reasonable care and followed instructions, they would be assured of a good grade and congratulations from friends and teachers. And fifty years later, there’s no reason to think the result would be any different.
Today marks the 75th anniversary of the U.S. dropping the atomic bomb on Hiroshima, Japan, August 6, 1945. At least 129,000 were killed. The gun-type weapon (one sub-critical mass fired into another sub-critical mass) exploded 2000 feet above the city, unleashing the power equivalent to 12 to 15 thousand tons of TNT.
The Potsdam declaration, demanding unconditional surrender, had been broadcast directly to Japanese civilians over KSAI radio, and millions of leaflets had been dropped.
Preparations were underway for an invasion of the home islands, and U.S. planners estimated U.S. casualties between 130,000 and 220,000, with between 5 and 10 million Japanese deaths. Nevertheless, the Japanese leadership did not heed the Potsdam Declaration, and made preparations to continue defending against an apocalyptic invasion.
On August 14, only after the bombings of Hiroshima and Nagasaki, Hirohito addressed the nation by radio:
Moreover, the enemy now possesses a new and terrible weapon with the power to destroy many innocent lives and do incalculable damage. Should we continue to fight, not only would it result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization.
Such being the case, how are We to save the millions of Our subjects, or to atone Ourselves before the hallowed spirits of Our Imperial Ancestors? This is the reason why We have ordered the acceptance of the provisions of the Joint Declaration of the Powers.
References
This month marks the 50th birthday of a pretty good idea, as evidenced by the cover story in the August 1970 issue of Popular Electronics. The article was penned by Russ Alexander, W6IEL, who was likely the originator. The article specifically addresses how to use a compact antenna from an apartment, and it makes use of Hustler mobile antennas.
So it’s fairly easy to change bands: You stop the car, get out, and swap out the resonator. But that doesn’t work very well if the antenna is mounted on the roof of your apartment building. And it doesn’t work very well if you want to change bands without getting out of the car.
So the author went to his metal shop, and made a piece which allowed him to mount up to four resonators on the same mast. For bands that are not being used, the coil acts as a trap, so the unused resonators have little impact on the transmitted signal.
The idea caught on. I first remember seeing one of these as a young ham in the 1970s in the parking lot at a hamfest on the car of prominent Minnesota ham Tod Olson, K0TO (then W0IYP). I remember thinking that it was a pretty good idea. Chances are, it originated with the magazine article shown here.
Shown in these pictures 
is the mobile antenna of W6LEN, an avid WWFF activator of Southern California parks and beaches. He uses the Hustler mobile antenna on a magnetic mount on top of his minivan. While the magnetic mount is probably too small to use in motion, he has had good success with this antenna, and it takes only a few minutes to deploy when he arrives at his destination. As with the 1970 article, he uses a homemade bracket to mount the four resonators.
