Category Archives: Radio history

Emerson Model 330, 1941

This ad for a 5-tube supereheterodyne broadcast radio appeared 75 years ago today in the November 16, 1941, issue of the Pittsburgh Press.

The set sold for $14.95 (complete, no extras), or could be bought on time for a quarter down and fifty cents a week.

The set appears to be model 330, which can be seen at the Radio Attic Archives. It was a standard “All American Five,” with a tube lineup of 12SA7GT, 12SK7GT, 12SQ7GT, 50L6GT, and 35Z5GT. A schematic and more photos are available at the Radio Museum. While the set’s tuning range didn’t extend much above the broadcast band, it was billed as easily receiving police calls, as well as distant stations.

1926 Popular Science Crystal Set

Ninety years ago this month, the November 1926 issue of Popular Science showed how to assemble this crystal set for the radio beginner, and offered a number of possible variations depending on the listener’s location and available stations.

The article noted that millions of Americans lived within five miles of powerful stations, but a surprisingly large number had not yet taken an interest in radio. But this simple receiver was billed as a mighty good way to get started, and predicted that many builders would eventually decide to upgrade and build a vacuum tube set. Parts selection kept in mind that many of the components, such as the variable condenser, could be used in the new set.

The author remarked that he had a friend who had a good five-tube set, but kept the old crystal set around for times when he wanted to listen to the radio alone. The headphones masked outside sounds, and he didn’t have to worry about wear and tear on his tubes.

The article suggested modifications of the antenna coil depending on the location and number of stations. It gave instructions on tuning. While moving the dial, you would adjust the crystal for the first hint of sound. When that was found, you would tune the dial for maximum sound, and then adjust the crystal for maximum volume. The crystal position could usually stay put for weeks. To prevent vibrations, the author suggested placing the set on a piece of cloth.

Dutch Reagan, WHO 1936

Eighty years ago today, the November 14, 1936 issue of Radio Guide carried a profile of the man who would, 44 years later, be elected President of the United States, Dutch Reagan.

As recounted by the magazine, Ronald Reagan walked into WOC radio in Davenport, Iowa, in 1932, looking for a job. The station was at the time synchronized with WHO Des Moines. The program director, Peter MacArthur, asked if he knew anything about football. When Reagan answered in the affirmative, MacArthur told him to stand by a microphone and imagine that he was at a game. The program director listened amazed for fifteen minutes before telling Reagan, “you’re broadcasting the Iowa-Minnesota game!”

When WOC and WHO split in 1932, Reagan went with WHO, where he broadcast the Chicago games by telegraphic report.

The article describes the future president:

He is over six feet tall with the pro- verbial Greek -god physique: broad – shouldered, slim-waisted and a face that would make Venus look twice before running to her man Zeus! And then he can talk, too. Dutch has a smooth -running “gift o’ gab” which never seems to falter, never is at loss for the right word. In short, he has quick wit and a nimble vocabulary, and large, too.

It noted that during his days at Eureka College, where he lettered in several sports, he never allowed anyone to call him Ronald, even though it was his name. The magazine also seemed to think that the young announcer had a future:

But there are new things beckoning. One is a career with the networks.
Like any ambitious announcer, Dutch, who never uses quotation marks about his name, has high hopes toward becoming the Husing or the McNamee of the airwaves, 1937 style. Watch him; he’s stream-lined. He might do it.

WGEA and WGEO, Schenectady, NY, 1941

Shown here as it appeared 75 years ago is a view of 100 kW shortwave stations WGEA and WGEO, the General Electric station at Schenectady, New York. The picture appears in the November 1941 of FM Magazine, along with an extensive look at the technical details of the stations, as well as those of GE’s sister station in San Francisco, KGEI (about which we wrote earlier).

The station had its start in 1925 with an experimental license under the call sign W2XAD. When the FCC deemed shortwave broadcasting to be sufficiently developed for commercial service in 1939, the station went on the air commercially.

GE received over 30,000 pieces of mail per year, and prepared its programs based on listener preferences. In addition to English, the stations had regular programs in Spanish, Portuguese, French, Dutch, Czech, and Chinese.

Frequencies used at the time were 6190, 9530, 9550, 9670, 15330, and 21590 kHz. Directional antennas beamed programs from Schenectady to Central America, Brazil, Europe, Argentina, and North Africa, and from San Francisco to South America and Asia.

Canada Carries On: 1941

Seventy-five years ago, the United States was less than a month away from entering the war, but Canada had been at war with Germany since 1939. In this ad from this date’s issue of Broadcasting magazine, November 10, 1941, the Canadian Broadcasting Corporation reminded potential American advertisers that Canada was carrying on. Despite wartime conditions, industry was at capacity, new factories were coming online, employment was at a peak, and most important for advertisers, retail sales were showing gains.

The CBC was serving wartime duties, and it reminded advertisers that it provided complete broadcast services to reach the Canadian market.

1916 Spark Coil

One thing that sometimes mystifying when looking at diagrams of early spark transmitters is that the descriptions often lack much detail as to the most important component, the induction coil or spark coil. A good description can be found in Electrical Experimenter magazine, November, 1916, from which this illustration is taken.

The “coil” is really two coils, plus an interrupter, and the operation is described here:

When the primary switch of such a coil is closed, the battery current passes through the first winding on the core and magnetizes it. This attracts the iron armature on the vibrator spring, as shown in Fig. 1, and when this spring breaks contact with the platinum tipped screw in front of it, the circuit is opened. At this juncture there is induced in the secondary winding a very powerful current. The spring-actuated vibrator returns to its former position in the fraction of a second and the process is repeated all over again.

The referenced schematic diagram is shown here:

Radio Bargain House, Birmingham, AL, 1941

Seventy five years ago this month, Pearl Harbor was still a month away, and the end of civilian radio production was still five months away. But radio retailers were starting to feel shortages, since many parts were in short supply due to wartime material priorities, and in some cases, the numbers of new sets available didn’t meet demand.

This led many retailers to take a closer look at selling used sets. Trade-ins were often viewed as a headache, and little effort was made to realize a profit from them. But the wartime economy made many retailers consider selling used radios. The November 1941 issue of Radio Retailing carried advice from the experience of M.M. Law, the proprietor of Radio Bargain House of Birmingham. Law got into the radio business by accident when running a hotel. A hotel guest turned a radio over to him for sale, and he placed a classified ad in the paper. He received fifteen calls in response to the ad. When he eventually lost the lease on the hotel, he decided to get into the radio business.

Law typically made a net profit of about $2 on each set. He often bought in bulk from other dealers looking to unload their trade-ins, sometimes as low as $1 per set. He typically invested about $3 fixing up each set, and quickly sold many for $6.95. He estimated that his average sale was between $12 and $15.

He continued advertising in the classified ads, since his experience was that this was where bargain shoppers looked. He always kept a set outside his shop, marked “today’s special,” and reported that he would often sell this set, with the buyer not bothering to look for others. In other cases, however, the set outside would entice a buyer to come in the store to buy a better set on the floor.

1936 Two Tube AC-DC Regen

The plans for this simple two-tube set appeared eighty years ago this month in Radio Craft magazine, November, 1936.

With plug-in coils, the set tuned 10 to 600 meters, and the author reported picking up numerous European and other foreign stations in New York City with excellent volume. The set employed two tubes, either type 37 or 76. One served as rectifier, with the grid and plate terminals tied together. The other served as the regenerative detector which was “capable of picking up even the faintest of signals.” An antenna of 30-100 feet was recommended. No ground connection was necessary, since the house current took care of the ground.

1956 Boys’ Life Radio Contest

Sixty years ago this month, the Boys’ Life Radio contest was once again underway, and radio made the cover of the November 1956 issue of Boys’ Life, depicting a ham who took a break from his duties in the school Thanksgiving play to work some DX.

This cover was the work of frequent Boys’ Life artist Harold Eldridge. According to the magazine’s description:

Miles Standish thought he had it touch, having to defend the pilgrims with just a handful of soldiers armed with blunderbusses. But pity the poor dramatics coach who has his Indians better trained than his hams. That friendly Algonkian in the window probably pictures the coach back in the high school auditorium, sweaty hands clutching the curtain ropes, but not John Alden, no Priscilla Mullen, and no Miles Standish yet appearing in the wings.

According to the magazine, the artist never did tell whether the DX’ing ham ever got back in time to cut some turkey on stage.

1941 One Tube Broadcast Receiver

The duo shown here are putting together the one-tube receiver described in the November 1941 issue of Popular Mechanics.

The set was billed as being for the beginner who wanted to graduate from the crystal set stage, or for the radio experimenter who enjoyed pulling in some DX, an ability this set possessed. The single tube was a 117N7-GT, so it required no A battery. Instead, the filament was powered by the AC line. The set was so efficient that it would run on a 30 cent 4.5 volt battery supplying the B+ voltage. The required parts, including the tube and battery, but not including the headphones, priced out at about $4.50, even accounting for recent price increases.

OneTubeRadio.com

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