Category Archives: Radio history

The Importance of Polarized Plugs

1952Mar2LifeThis picture appeared 70 years ago today in the March 2, 1953, issue of Life magazine.

The gentleman in the center is A.W. Shackleford, the mayor of Lethbridge, Alberta. He is demonstrating the importance of using grounded outlets, or at least polarized plugs. He was speaking into one microphone, addressing 800 Valentine’s Day dancers. A local radio station was covering the event, and being a politician, he grabbed that microphone as well.

Unfortunately, a “difference in grounding systems” between the two systems caused there to be a difference of 50 volts through the two mike stands. Undoubtedly, one or both of the two systems had one lead of the power connection attached directly (or through some resistance, hence there only being 50 volts present) to the chassis. All is well if that’s the neutral lead of the electric wire. But one of the two systems had the hot side of the power lead hooked to the chassis.

A radio announcer (left) and alderman tried to pull His Worship the Mayor away from the mikes, but the current froze him in place, and he was not freed until the power was disconnected. He survived the incident, and went on to win future terms as mayor.



1923 Radio Listings

23Feb1923For a snapshot of what was on the radio a hundred years ago today, here’ the radio page from the February 28, 1923, issue of the Washington Evening Star.  Click on the image for a larger version.

If you ever had an old radio with a switch marked “marine band,” then perhaps you could have heard what was being played on NAA at 8 PM, namely, a concert by the U.S. Marine Band, concluding with the National Anthem, right before the 10:05 PM weather report.

If your set could pull in Philadelphia, then there was a bedtime story at 7:10 PM. If you missed that one, maybe you could get the one from Chicago at 7:50.



1963 GE Clock Radios and Phono

1963Feb27If you were in the market for a radio or phonograph 60 years ago, you could pick up one of these at the local drug store, although the ad admonished you not to call it that.

Shown here are the GE Model 1530 stereo phonograph, and models C465 and C467, and models C433 and C434 clock radios.  The radios are typical “All American Five” circuits.  Come to think of it, my first ever radio of my very own was a similar model (but without the clock) also purchased from a local drug store.

The ad appeared in the Washington Evening Star, February 27, 1963.



War Emergency Radio Service, 1943

1943FebRadioRetailing2We’ve previously discussed the War Emergency Radio Service (WERS), a wartime civil defense service set up to harness the talents of amateur radio operators who were otherwise off the air for the duration of World War II.

Eighty years ago this month, the February 1943 issue of Radio Retailing takes a look at how the local radio dealer might fill part of the need in supplying equipment and expertise. The illustration shown above is a mobile repair facility, and undoubtedly some of the personnel shown here service radios as their civilian job as well.

In addition to radio operators, a role likely filled by hams, the dealers might fit into one of five other categories: Maintenance, procurement, construction, repair, and training.



1938 Distance Learning

1938FebRuralRadioThe students shown here are now almost 100 years old, but 85 years ago, they were learning about the atmosphere in science class. These students, Marian Oakley, Henry Kehrer, Hannah Esterman, and Bruce Kunkel, were receiving instruction in person from science specialist Harry A. Carpenter, but hundreds of other students were taking part in the same class by radio, on station WHAM.

For several years, the Rochester, NY, schools had been conducting this sort of distance learning via radio. Afternoons, radios would be switched on in classrooms both in and outside of Rochester, and students would get their lectures by radio. Lessons could include well known guest speakers, music programs featuring the Rochester Civic Orchestra, and programs on books presented by the Rochester Public Library. The photo shown here appeared in the February 1938 issue of Rural Radio, and the students shown here attended Frank Fowler Dow School No. 52.



1938 Utah Junior Transmitter Kit

1938FebPM3Eighty-five years ago this month, the February 1938 issue of Popular Mechanics featured this 25-watt CW transmitter kit, the Utah Junior transmitter from Utah Radio Products of Chicago. The kit sold for under $16, not including tubes, meter, and crystal. The transmitter used a 6L6, with the RF stage mounted on one chassis and the power supply mounted below it for a neat design. To make assembly foolproof, small components came pre-mounted on the chassis.

You can read more and see a nicely restored example at W0VLZ’s blog.



Burns’ Electric Shop, Lancaster, WI, 1923

1923Feb21If you lived in a small town or out in the country a hundred years ago, you probably heard of radio. And if you were lucky, you probably got a chance to hear one. But it would have seemed risky to buy one. Would you be able to pick anything up, or would it wind up being a waste of money.

Burns’ Electric Shop in Lancaster, Wisconsin, took away the risk, as shown in this ad in the Grant County Herald, February 21, 1923. They would put a set in your house for five days at their expense, and then the radio would sell itself. It probably wasn’t a big risk. The town was in southwest Wisconsin, and eastern Iowa was a hotbed of radio activity at the time. At night, those stations would come in loud and clear, as well as stations in Chicago and more distant places.



1938 Directional Antenna

1938FebPM1This gentleman is adjusting his directional antenna, using an interesting design shown in the February 1938 issue of Popular Mechanics.

1938FebPM2The antenna itself consists of two doublet antennas at right angles. The combined antenna is fed with a four-conductor feedline, and down in the shack is a switch, allowing for nine different combinations. While this design wouldn’t work with today’s ubiquitous coaxial cable, it probably did help boosting your signal in one direction, or nulling out some interference.

It appears to be a commercial product from TACO, the Technical Appliance Corp. of Philadelphia, which was purchased in 1961 by Jerrold, and then by General Instrument Corporation in 1967.



1948 Metal Detector

1948FebPracMech

The plans for this three-tube metal detector appeared in the British magazine Practical Mechanics 75 years ago this month, February 1948.  The general circuit is similar to inexpensive metal detectors sold today, although the modern versions are much smaller as they are transistorized.

According to the author, many coins, rings, and other metallic objects, some of considerable value, were found on the sites of old Roman camps in Dorset.

The general idea of this circuit is quite simple.  It  consists of an RF oscillator, the coil of which is held near the ground.  When that coil comes into the proximity of metallic objects, the change in permeability results in a change of frequency.  This type of metal detector can work quite well, but it does require a bit of practice.   The detector makes a loud squeal, and the best way to use it is to tune it carefully so that the squeal just barely disappears.  If it’s done carefully, the detector can be very sensitive.

Many people have bad experiences with the types of inexpensive metal detectors shown here, some of which look like toys, but that’s because they didn’t take time to carefully adjust them and practice.  It’s best to start out indoors, toss some metallic objects on the floor, and then carefully adjust the metal detector and see how it reacts when the coil is brought near the item.  After some practice, you can take it outside and look for treasure.  The metal detector above, with which Roman coins were found, is actually the equivalent of any of these detectors, and with a bit of practice, one of these will give similar results.

1948FebPracMech2

 



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1943 Emergency Generator

1943FebQSTEighty years ago this month, the February 1943 issue of QST showed this emergency generator. Hams might have been off the air for the duration, but they still had an interest in emergency needs, including WERS operations.

It was powered by a Briggs & Stratton gasoline engine normally rated at 1-3/4 HP, but the accompanying article noted that it was capable of up to 2-1/2 HP maximum as shown here. It was capable of putting out 120 volts thanks to a salvaged Dodge 12-volt generator, rewound, and was capable of putting out over 1400 watts. The field coils needed power, and that was provided by a second six-volt generator also driven by the engine.

The estimated cost of the whole unit was said to be $7.50, although the author admitted that this figure might have been somewhat “under-exaggerated.” The set shown here was the second one constructed, and a third was underway.

One of the gentlemen shown on the cover, although they’re not identified, was apparently Warren Copp, W8ZQ. The article mentioned that he was the father of then-eight-year-old actress Carolyn Lee.  We’re not sure exactly why that’s relevant, but like the author of the QST article, we believe that’s the kind of thing our readers would want to know.