Author Archives: clem.law@usa.net

1960 British 4 Tube Superhet Portable

1960JuneRadioConstructor11960JuneRadioConstructor2Sixty years ago this month, the June 1960 issue of the British magazine Radio Constructor carried the plans for this four-tube superhet portable, dubbed by the magazine “The Regent.” The set tuned both the longwave and mediumwave broadcast bands, and was said to be sensitive. The set was easy to construct, thanks to the use of a printed circuit board.

For those who needed help tracking down all of the parts, one of the magazine’s advertisers, Radio Component Specialists, 337 Whitehorse Road, West Croydon, had them advertised, and they could be purchased as a complete kit, or separately.

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Vera Lynn, 1917-2020

We are sad to report that Vera Lynn has died at the age of 103.  She was known in Britain as the “Forces’ Sweetheart” for her songs that helped raise morale during World War 2.  Her most famous recording was “We’ll Meet Again,” which was recently echoed by Queen Elizabeth II in her address to her subjects about the coronavirus.



1950 Four Tube Portable

1950JunePM1I don’t know if they’re on the beach at Benton Harbor, but seventy years ago this month, this couple were listening to some entertaining program on a radio built into a metal lunch box, as described in the June 1950 issue of Popular Mechanics.

1950JunePM2The set was a four-tube superheterodyne, with a 67.5 volt battery supplying the B+ and 3 flashlight batteries in parallel lighting up the filaments. Perhaps the set served as inspiration for the famous Gilligan’s Island radio, as it featured a telescoping whip antenna attached to one side of the internal antenna coil. The built-in antenna was said to pull in local stations, and with an outdoor antenna, even distant stations would supply loudspeaker volume.

The finished set had a professional look thanks, in part, to a dial scale printed in the magazine. For the finishing touch to the set, the dial could be cut out of the magazine and cemented to the case.

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Camping With the Phonograph: 1920

1920JuneTalkingMachineWorldA hundred years ago this month, the June 1920 issue of Talking Machine World carried this ad for the Columbia Grafonola phonograph, and reminded readers that the joys of vacation are redoubled when music is brought along.

The compact instrument in its traveling kit could be tucked away safely in any corner of an automobile, motor boat, or even canoe. It stayed out of the way until needed for the latest music for dancing.



Electrostatic Generator

1970JunSciElecFifty years ago this month, the June-July 1970 issue of Science and Electronics showed how to put together this electrostatic generator, as well as the accompanying Leyden jar and electroscope.

It consisted of a plastic jar which was turned by the crank to rub against a piece of wool. A pickup wire collected the charges and conducted them to the metal ball. This could be used to charge the Leyden jar. For bearings, the device used roller skate wheels.

1970JunSciElec2Emergency preparedness buffs will notice that the electroscope, at left, looks very similar to the venerable Kearney Fallout Meter (KFM) used for detecting nuclear radiation. Indeed, they do rely on the same principle. In the presence of ionizing radiation, the charge will slowly dissipate, allowing the leaves to get closer together. This electroscope is not calibrated. Therefore, it would not be able to provide an accurate radiation dose reading. However, this generator would be useful to charge the KFM.

For young scientists without any ionizing radiation at their disposal, the magazine describes a number of interesting experiments, any one of which would be sure to bring home the blue ribbon at the next science fair.  To guarantee the top prize, one interesting experiment would be to purchase a small uranium sample.  Charge up the electroscope and see how long it takes to discharge.  Then, repeat the experiment with the uranium inside the electroscope and see how much faster it discharges.



Increasing Your Ground Conductivity

1940JunPMgroundEighty years ago this month, this father-son team lived in an area with poor ground conductivity due to dry sandy soil. Undaunted, they still managed to hook up a good ground for their radio, thanks to this self-explanatory helpful hint from the June 1940 issue of Popular Mechanics. The funnel is permanently soldered to the pipe serving as ground rod. Therefore, whenever the ground conductivity gets poor, it’s a simple matter to pour in some water and squeeze the last mho out of the soil.

If the idea sounds familiar, it’s probably because you previously saw it here.



Flag Day 1920

WashingtonEveningStar06141920This illustration appeared a hundred years ago today on June 14, 1920, in the Washington Evening Star.

The paper reported that the 143rd anniversary of Old Glory would see celebrations around the city. Children in all of the schools took part in special exercises, and veterans of the World War took part in paying tribute. The evening culminated with a mass meeting an patriotic pageant on the east steps of the Capitol.

President Wilson was unable to attend, but sent a message. The Marine Band (presumably, about 2-5 Mhz) played, along with a chorus of a thousand voices singing patriotic and folk songs.

Secretary of State Bainbridge_Colby had spoken the prior evening, stating:

The American flag speaks today, as it has always spoken, a message of cheer and help to the oppressed; a clear note of leadership to the aspiring in all lands, a note of aid and succor to liberty wherever liberty falters or is assailed. It speaks for the redemption and not the repudiation of the nation’s pledges.

It is the flag of work, of service, of courage. It is the flag of chivalrous men and noble women. It is a flag of glory. It is a flag which has moved forward on every field, never backward, and today and at this hour it cannot be an emblem of a moral retreat upon the field of highest service, the rescue of the world, to which our destiny as a nation calls us.

When Secretary Colby spoke those words, American boys, and a few girls, had only recently returned from the fields of Europe. Some of them never returned.

Did they rescue the world? They tried, and they did so very imperfectly. A quarter century later, their sons (and a few of their daughters) went back under the same flag. They didn’t do a perfect job, either. But the flag moved forward, and not backward, toward the rescue of the world.

Today, on the flag’s 243rd anniversary, it has two more stars, is still a flag of glory, and can’t be an emblem of moral retreat. Do we have a perfect Union? No. We have disease; we have racism; we have violence; and we probably have a hundred other problems that we can’t even see. But as heirs of those men and women who went before us, we too can move forward to make this a more perfect Union and a more perfect world.



1945 Magnets

1945JuneRadioCraft3This young woman, shown in the June 1945 issue of Radio Craft, is demonstrating the power of the alnico magnet, which, according to the accompanying article, can lift 4450 times its own weight. Wartime progress in the development of magnets promised many new postwar consumer products.



1920 Metal Detector

1920JunElectExp1A hundred years ago this month, the June 1920 issue of Electrical Experimenter showed this ingenious metal detector. Like most metal detectors, it relies upon the inductance of a coil increasing in the presence of metal.

This one uses two identical coils. A buzzer is pulsing a voltage through them, but they are wound such that they are 180 degrees out of phase. Thus, the two signals will cancel out, and nothing will be heard through the headphones. But if one of the coils comes near metal, the inductance changes, and the two signals no longer cancel out. Thus, the buzzing can be heard through the headphones.

The circuit was said to be able to detect a one square foot piece of iron down five feet, or a quart of washers a foot down.

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