Category Archives: Radio history

Radio Goes to School: 1944

Seventy-five years ago, the over 170,000 students in the Philadelphia schools were getting a good dose of the fourth “R.” In addition to reading, ‘riting, and ‘rithmatic, the schools were taking full advantage of Radio. Thanks to the community spirit of the city’s commercial radio stations, regular lessons were scheduled. For example, for the elementary grades, WFIL carried “Studio Schoolhouse,” an educational program three days a week. The Monday program allowed the students, left, to participate in dramatized scripts about how they could help the war effort.

The pictures and accompanying article appeared in the June 1944 issue of Tune In magazine.

1929 Soviet One Tube Amplifier

Ninety years ago this month, these three Soviet radio experimenters were putting together what appears to be an audio amplifier, following the plans contained in the June 1929 issue of Радиолюбитель (Radio amateur) magazine. Apparently, they’re either small experimenters, or they’re using a very large tube.

Unfortunately, the scan is rather low quality, but the word усилитель (amplifier) appears in the title. There are headphones hooked to the plate, so it must be an audio amplifier. The circuit is simple, with the only control being the rheostat on the front panel to control the filament voltage. It’s likely that the input of the amp would be hooked to a crystal set, with the tube amplifying the volume to a more listenable level.

Not to be outdone, these Soviet girls are shown in the same magazine putting the finishing touches on another electronic project.

Majestic Model 130 Portable, 1939

Eighty years ago this month, the young woman shown here was pulling in some musical entertainment on her way to the beach, courtesy of her Majestic model 130 portable radio. The “camera style” set, billed as the world’s smallest portable, featured a superheterodyne circuit, with a 3-tube lineup consisting of 1A7GT, 1N5GT, and 1D8GT, powered by a 60 volt B battery and a 1.5 volt battery to light the filaments.

The ad here appeared in the June 1939 issue of Radio Today. You can see a restored example of the set playing at this video:

https://www.youtube.com/watch?v=lhrNX9HVt5o

1949 Radio Hat

Seventy years ago this month, the cover of the June 1949 issue of Radio Electronics showed the very stylish and useful Radio Hat, a product of the American Merri-Lei Corporation of Brooklyn, New York. I’ve only seen one of these in person, and I was always curious as to how well it performed. The magazine put the set to a test, and declared it to be a good performer.

With a price of under $8, the editors assumed that the original market was for children. But for travelers or sports fans, the set was quite adequate for adults. The magazine reported that in New York, it pulled in all of the stations well, especially outdoors, and even performed quite well inside steel buildings. The hat weighed only 12 ounces and was adjustable. The batteries, a 22.5 volt B battery and two A batteries, were carried in a pocket and connected to the hat with a cord. An earphone was in the hat over the left ear, but it was possible to move it to the right.

The two-tube set used a 1S5 as regenerative detector, with a 3V4 amplifying the audio. The tubes were coated in plastic to prevent them from shattering in their exposed position.

If the model wearing the hat looks familiar, it’s because she is a 15-year-old Hope Lange, who went on to become an actress, probably most familiar as Mrs. Muir in the Ghost and Mrs. Muir. You can also read more about the Radio Hat at its Wikipedia article, which is based largely upon the Radio Electronics article.

1959 British One Valve Radiogram

Sixty years ago this month, the June 1959 issue of British magazine Radio Constructor showed how to put together this one valve radiogram. For readers on this side of the pond, that means a one-tube radio-phono combination. A single ECL80 dual tube served as audio amplifier for both the radio and phonograph. A simple crystal set using a germanium diode pulled in the local stations on either long wave or medium wave.

In addition to showing how to put together the simple circuit, the magazine promised that the cabinet work would be lucidly explained so that no difficulty would be experienced, even by a beginner. A power transformer assured safe operation, and a single DP3T switch was used to select longwave, mediumwave, or gramophone.

Radio Direction Finding

Sixty years ago this month, the June 1959 issue of Electronics World carried a good basic introduction to marine direction finding (DF). The cover image shows a number of commercially made DF units, and the article explains how they work.

While the technology looks archaic, it actually still works quite well, and will continue to do so as long as there are AM radio stations on the air. While commercial direction finders are no longer readily available, virtually any AM radio will work well, as long as the antenna is directional. And if the radio has an internal loop antenna, it will be directional.

For example, the inexpensive portable shown at the right will perform very well. (It’s available at Amazon at this link, but any other inexpensive portable will work just as well.) You simply rotate the radio until the signal is the weakest. At that point, the internal antenna (usually in parallel with the top of the radio) is in a straight line with a station. You place a ruler on the map over that station’s location, and draw a line in that direction. You repeat the process with a second station, and where the lines meet is your location. You’ll need to orient the map, so if you don’t know what way is North, it’s a good idea to have an inexpensive compass. And you don’t really need a ruler. You place the map on a table oriented with the Earth–the top of the map facing North–and then use the top of the radio as your ruler.

This method is surprisingly accurate. It’s very easy to find your location within a mile, and with some practice, you’ll be able to narrow it down even more. It’s not quite as accurate as GPS, but if GPS ever becomes unavailable for any reason, this is an excellent backup method. The example shown at the left is typical. By knowing the exact location of radio stations in Chicago, Milwaukee, and Benton Harbor, MI, the boat can find its location within a few hundred yards.

Radio station locations are shown on maritime and aeronautical charts. You can also find the exact locations of AM radio stations from the FCC database.

Sparton Model 590-1 Portable, 1939

Eighty years ago this month, the June 1939 issue of Radio Retailing carried this ad reminding dealers that they should stock up on portables for campers, collegiate-ers, picnic-ers, and swingsters.

The set shown is the Model 590-1. The superheterodyne set featued a tube lineup of 1A7G, 1N5G, 1H5G, and 1A5G, with a 35Z5GT rectifier for use at home. The set switched automatically from household current to battery by removing the line cord.

Amateur TV, 1959

Sixty years ago this month, the cover story of the June 1959 issue of Popular Electronics was all about the small but growing number of amateur radio operators on television. The 70 cm band had been allocated for TV, and pockets of hams were putting it to use.

Cameras were very expensive, and required a lot of studio lighting. So some hams were content to get on the air with a flying spot projector and slides, similar to the test device we featured earlier. An existing TV receiver was used to illuminate the slide, with a photocell picking up the image as each line was illuminated.

USS Squalus, 1939

In drydock after salvage. Wikipedia photo.

This picture above appeared 80 years ago today in the June 16, 1939, issue of Radio Guide. Shown is a Washington, D.C., family gathered around the radio, obviously clinging to every word of the news announcer. They are the family of William Isaacs, who was aboard the Navy submarine U.S.S. Squalus when it sank off the coast of New Hampshire on May 23, 1939, killing 26 crew members. The remaining 33 aboard (32 crew and one civilian) were rescued. The ship was initially in contact with a companion ship by telephone line to a buoy, and the men were rescued from 243 feet of water thanks to the McCann Rescue Chamber.

Wikipedia photo.

The ship was eventually salvaged, and went on to serve in the Pacific during World War II as the USS Sailfish. The ship was scrapped after the War, but the conning tower, shown here, was preserved after the war as a memorial at Portsmouth Naval Shipyard.

The family shown here eventually received good news, as Isaacs was one of the men successfully rescued from the sunken ship.

Clock Radios: 1959

Sixty years ago this month, the June 1959 issue of Popular Science explained how the ubiquitous clock radio worked, using a General Electric model as the example. This model included a sleep feature which let the radio play when going to bed. In the morning, the radio would first come on, followed by a buzzer ten minutes later. It also included an outlet at the back for a small appliance.

According to the magazine, the clock radio first came out in 1947, and in the previous year, 2.3 million of the sets were sold by 25 different manufacturers.

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