Category Archives: Radio history

1940 4 Tube Portable

1940JunePM1Shown here are just a few examples of how fun in the summer of 1940 could be augmented with this handy portable receiver, as described in the June 1940 issue of Popular Mechanics. The set ran off a commercially available (at least until the war came along) combination A/B battery which would allow the set to be run on trains, boats, camps, summer homes, or the lawn for up to 200 hours. Provision was made for an external antenna, but the set’s internal loop antenna would pull in signals from up to 100 miles away, and 1500 miles at night.

Parts for the four-tube superhet were said to cost about $7.50, not including the battery and case.

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Radio Sales Corp., Milburn, NJ, 1945

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Seventy-five years ago this month, there was a clear sense that the war would soon be over, and business as usual would return to Main Street. The June 1945 issue of Radio Retailing offered on its cover this example of Radio Sales Corp., 327 Milburn Ave., Milburn, N.J. The owner, Milton Marks, declared that the dealer with the best sales argument and best-equipped organization would get the business in the competitive postwar market. He further stated that “catch as catch can” merchandising would be catastrophic.

Marks was getting ready to throw his merchandising of radios and appliances into high gear. He kept a priority book of customers who really intended to buy and genuinely needed new appliances, and those customers would get the first shipments in the order received.

His store focused on providing excellent service and honest dealing. He reported spending about $750 per year on newspaper advertising, and an additional $100 on scholastic advertising, which he noted was a builder of goodwill.

As seen in the Google streetview below, the block is still clearly recognizable. In fact, the old Radio Sales Corporation location is currently vacant. Perhaps a modern electronics retailer wants to move in and take advantage of some of that old goodwill.

MilburnNJ



1940 Portables

1940MayRadioRetailingEighty years ago this month, the nation’s radio retailers were headed into the summer months, which had previously been known as the summer slump. But the April 1940 issue of Radio Retailing magazine noted that the portable set, really only two years old, had been responsible for the virtual elimination of the 1939 summer slump.

The magazine gave a number of pointers to promote the sets, which it pointed out could be marketed to those traveling by trailer, by plane, by boat (as shown below), or, as shown on the cover, by train.

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1920 One Tube Regenerative Receiver

1920MayPS2This simple regenerative receiver circuit appeared in Popular Science a hundred years ago this month, May 1920. It was sent in to the magazine by one Edward T. Jones, who reported that it used a resonant antenna, connected by what he called a “balancing circuit.” He reported that this circuit drew signals from the antenna in a much greater proportion than static.

He reported that connecting the optional variable capacitor resulted in greater signal strength, but with some loss of selectivity.



1940 Portable Hand-Crank Radio-Phono

1940MayPMxFrom 80 years ago, here’s another example of a hand-crank phonograph, but with electrical rather than mechanical sound reproduction. The set in question is a portable radio-phonograph combination.

The radio was a four-tube superhet, powered by batteries. It made perfect sense to use the hand-crank motor, since the motor would unnecessarily run down the batteries.

The set, which appears to be from General Electric, was shown in the May 1940 issue of Popular Mechanics.



1940 Six Tube Superhet

1940MayPM4Eighty years ago this month, the May 1940 issue of Popular Mechanics showed how to put together this project for advanced radio hobbyists. It was a three-band six-tube superheterodyne receiver capable of tuning 530 kHz to 18 MHz. It was an update to a four-tube set shown in the December 1939 issue, as that project had left space on the chassis for the upgrade, and most of the parts from the original set were re-used.

Unfortunately, I don’t see any indication that the set had a BFO, so while it was probably a good receiver for voice signals, it couldn’t be used for code.

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1940 One Tube “Baseball Special” Portable

1940MayRadioCraftEighty years ago this month, the May 1940 issue of Radio Craft carried the plans for this simple one-tube broadcast set dubbed the “Baseball Special.” The author put the circuit together to be able to listen to the play-by-play while sitting in the stands. He noted that the set was never meant to be a DXer, but it pulled in the local stations, the ones that broadcast the game.

The circuit used a 1D8GT triple diode-triode-pentode tube. The diode section was not used, the pentode was used as a regenerative detector, and the triode served as audio amplifier. A short piece of wire served as the antenna. A camera case was used to house the radio, although the author noted that the works could just as easily be tossed into a paper bag.



1945 One-Tube Space Charge Receiver

1945MayRadioCraftThis wartime circuit from the May 1945 issue of Radio Craft is about as simple as it gets. It was sent in to the magazine by Jim Brophy of Chicago, who reported that it gave good volume on all of the local stations.

What’s somewhat remarkable–in addition to the low part count–is the fact that the set used two flashlight batteries for the filaments, and only three penlight cells for the “B” battery. The low voltage requirement was due to the space-charge principle. The grid closest to the cathode in the tetrode tube (in this case, a type 49) was kept at a positive voltage. The magazine’s editors noted that this was one of the oldest effects in tetrode tubes, but had dropped into obscurity. But with wartime shortages of B batteries, the magazine noted that it was worth some experimentation.

The name of the person who submitted the idea, Brophy, rang a bell.  It doesn’t sound like a very common name, but also in 1945, one Loretta Brophy was working at WABD-TV in New York.



1945 Ecophone Model EC-1 Receiver

1945MayRadioCraft2Yesterday, we showed a Hallicrafters “morale” receiver from 1945, and today, we see this ad for another one, from the May 1945 issue of Radio News.  This femme fatale has taken an interest in this soldier, and it’s not out of the question that she’s a spy.  Fortunately, she won’t get anything out of him, because all he does is sing the praises of the Ecophone Model EC-1 morale receiver.

He’ll tell her that the set is a compact communications receiver with every necessary feature for good reception, and that it tuned from 550 kHz to 30 MHz in 3 bands.  He’ll let slip that it has an electrical bandspread, six tubes, a built-in speaker, and that it runs off 115-125 volts AC or DC.  But since none of that was classified, the Army had nothing to fear.



Hallicrafters RE-1 Sky Courier

1945MayRadioNewsShown here is the Hallicrafters Model RE-1 Sky Courier receiver from 1945. For the G.I. far from home, the radio was as important as mail call in staying connected with home. Early in the war, whatever receiver could be found was pressed into service, but the harsh conditions meant that the military needed a rugged “morale” set, and the RE-1 was the answer.

The set could operate from batteries (90 and 9 volts) or AC power. The method for switching was ingenious. To switch to battery operation, the line cord was inserted into a jack in the back of the radio. The prongs of the cord completed two circuits, and thus served as a DPDT switch, connecting the batteries. The set tuned 550-1600 kHz and 2.8-19 MHz, and contained a built-in antenna.

Above all the set was rugged, and was designed to resist both corrosion and fungus.

The picture and description appeared in the May 1945 issue of Radio News.