Category Archives: Radio history

1949 Two Tube Superheterodyne Portable

1949JunePM11949JunePM2The scouts shown above are taking a break from their campout to pull in some local broadcast stations on the two-tube superheterodyne receiver they constructing from the plans in the June 1949 issue of Popular Mechanics. The set used a 1R5 and a 1U5 tube and a 15 foot antenna to get good volume on the local stations. According to the magazine, the set rivaled any regenerative receiver, without the possibility of an annoying squeal.

According to the magazine, the rugged little set was ideal for camping or other knockabut use. It could be transported in a small cardboard container, or, if the builder preferred, in a cabinet.

The filaments ran off two flashlight batteries in parallel, with a 67.5 volt B battery.  For strong stations, a 45 volt battery could be substituted.

1949JunePMschematic



1938 New England Hurricane

1944JuneRuralRadioThe article shown above appeared in the June 1939 issue of Rural Radio magazine, detailing an award to Wilson E. Burgess, W1BDS, for his work during the 1938 New England Hurricane.  The storm was one of the deadliest to ever hit New England and Long Island, with an estimated 682 killed.  It’s the strongest hurricane to hit New England in modern times, possibly eclipsed by the Great Colonial Hurricane of 1635.

While this article is short on details, more can be learned from Clinton DeSoto‘s 1941 book Calling CQ.

Rhode Island hurricane damage. Wikipedia image.

The storm was poorly forecast, and hit Burgess’s hometown of Westerly, R.I., with little warning the afternoon of September 21, 1938. Burgess was working as the manager of the appliance department at Montgomery Ward when the storm blew out the windows of the store. Panicked people were running up and down the aisles of the store. It soon became apparent that a hurricane was in progress.

He quickly collected a quantity of batteries and started for home on foot. He struggled up the street as trees fell around him. At the police station, he met up with another amateur, George Marshall, W1KRQ. Together, the set off toward Burgess’s home with the batteries. Eventually, they were able to hitch a ride on a county truck, but it was soon blocked by trees and they again had to continue on foot.

They eventually made it, but he found that the edge of his garage that had supported his antenna had been swept away. He went out in the 65 MPH winds to put it back up, and eventually had to settle for wrapping the wire around his house.

W1KRF, W1BDS, W1KRQ at the makeshift station.  QST, Nov. 1938, p. 12.

W1KRF, W1BDS, W1KRQ at the makeshift station. QST, Nov. 1938, p. 12.

By this time, of course, the power was out, and there was no way to power Burgess’s normal 600 watt transmitter. Working by kerosene lantern, the two men worked for two hours building a one-tube transmitter to use with the batteries carried from the store.  DeSoto reports that the windows had been blown out by this time, and daughter Jane Gail Burgess, shown in the photo above, then three months old, was crying in terror.

Finally, they had the transmitter and a makeshift receiver ready, and Burgess started putting out a QRR–the then-distress call. Unfortunately, nobody really knew that an emergency was in progress, and their weak signal simply wasn’t heard over the interference of a normal busy ham band. They moved their CW signal up to the phone band, reasoning that the CW signal would stand out there. The trick worked, and soon W2CQD in New Jersey answered the call, with W1SZ in Connecticut (QST managing editor) later taking over. For the next five days, the Connecticut station maintained contact.

Neighbors eventually got word to the local Red Cross that radio contact had been made, and the house soon became a center for relief activity. The first official message was to Red Cross headquarters in Washington, but that message was not accepted, since it was signed merely “Westerly Red Cross.” Eventually, the name of the local chairman was added, and the message was accepted.



1959 Springfield Enterprises CB

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1959JuneEI2The gentleman shown here is obviously a mover and shaker, and he’s staying in touch thanks to a portable citizen’s band transceiver that he assembled himself from a semi-kit. The electronics came pre-wired, but he had to do the final assembly himself, a process that took about three hours.

The set, from a company called Springfield Enterprises, sold for $41.90, plus $5.73 for the battery. The set was reviewed in the June 1959 issue of Electronics Illustrated. The magazine had two of the units, and found the reliable range using the whip antennas to be about a quarter of a mile.

The top photo is taken at Times Square, as revealed by this photo.

Meadwell’s Radio & Electric, Saskatoon, 1944

1944JuneNRNThe cover of National Radio News, the publication of the National Radio Institute home study school, for June-July 1944 shows the exterior of Meadwell’s Radio & Electirc, 110-3rd Ave. S., Saskatoon, Saskatchewan.

Shown by the truck at the left are the owners, Mr. & Mrs. John D. Meadwell, both graduates of of NRI. They wrote to the magazine of their gratitude to the school for the training and cooperation received, and that they owed their success to NRI.

They reported that they had done wonderfully well and believed that they had the largest radio repair shop in Saskatoon.

The building in which the shop was located was known as the Dinkle Building, and was destroyed by fire in 1986. The three-story building had shops on the lower level, with the top two floors being residential. More pictures can be found at the Saskatoon Public Library website.



Kathryn Hutchinson, 1939

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Shown here in the June 1939 issue of Radio Craft is sixteen-year-old Kathryn Hutchinson of the famous Flying Hutchinsons. According to the magazine, she was an amateur radio operator, although her call sign was not specified. She is shown here working on part of the Amateur Radio display of the 1939 World’s Fair, which was part of the Westinghouse exhibit in cooperation with the ARRL.

Flying Hutchinsons, circa 1932. Wikipedia image.

The Flying Hutchinsons had earned their fame in 1931, when Kathryn was about eight, when they visited the capitals of all 48 states by air. The next year, when Kathryn was nine, the family achieved further fame in an attempted around-the-world flight. The attempt ended off Greenland when the plane crash landed and the family was stranded for several days before being picked up by a fishing trawler and taken to the U.K. Kathryn’s parents, George and Blanche, wrote two books detailing their adventures, The Flying Family in Greenland (1935) and Flying the States (1937).

You can see Kathryn and the rest of her family in this 1932 newsreel in which her father defends the flight:

You can hear Kathryn and the rest of the family at this 1939 radio program.  More information is available at this link.  I believe the program is actually a dramatization of the completion of a flight that never took place.  Begun in 1939, the Hutchinsons made it as far as Mexico before the war broke out, making impossible a visit to all nations on earth.

Kathryn Hutchinson James died in Florida in 2015 at the age of 92. At the time of her death, she was a registered Republican.  Her mother, Blanche D. Hutchinson died in 1995.



1944 Tube Substitutions

1944JuneRadiocraftWartime parts shortages often meant that radio servicemen had to be creative, and that often meant tube substitution. If the replacement tube was not available, it was often possible to substitute one that was. The substitute often had similar or even identical electrical characteristics, but had a different size plug or pin configuration.

The June 1944 issue of Radio Craft, like many other radio magazines of the era, carried some pointers. The illustration shows common adapters. The base was made of a burnt out tube (perhaps the one being replaced), and the top was a new socket for the new tube. When tubes became available, the adapter could be removed and the original inserted in the socket.



Voice of America: 1944

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Transmitter engineer flipping the switch at antenna farm to beam program to Europe.

Seventy-five years ago this month, the June 1944 issue of Popular Mechanics highlighted the shortwave broadcasting efforts of the Office of War Information (OWI). The magazine dubbed the American shortwave stations the “Voice of America,” a name which would become official in following years.

The magazine noted that the Nazis had a head start on the radio war, since Germany had over a hundred transmitters spewing propaganda to the world. The United States had only sixteen, all under private ownership. But even though it took some time to get going, the OWI wass directing a 24 hour flow of news and information around the world. The magazine noted that America strictly adhered to factual news.

Jamming was rampant, and broadcasts were normally read at a hundred words per minute to compensate. When poor conditions dictated, this was sometimes slowed to 80 words per minute. The OWI knew that there were listeners. After the liberation of parts of Italy, a survey indicated that one in ten families heard allied programs, despite severe penalties for tuning in.



Dangerous Way to Listen to Radio: 1929

1929JunePMAccording to the caption of this picture from the June 1929 issue of Popular Mechanics, the gentleman shown above is merely “sick.” But he doesn’t look very good, and we suspect he may have already succumbed to electrocution.

He wanted to listen to the radio, but they didn’t want to drag the radio into his room. Nor did they want to run any wires. So someone came up with the bright idea shown here. There was already a perfectly good set of wires in place, namely, the house electric wiring. So they decided to put it into service by feeding the radio output into the power wires, and plugging in a set of headphones on the other end. A 2 μF capacitor was put in place as a gesture toward safety.

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The first problem seems to be that it wouldn’t really work. Whatever audio made it through would be drowned out by the 60 cycle hum, assuming that the lighting current was AC, which it was in most of the country by that time.

And unless my back-of-the-envelope calculations are wrong, the capacitor will have a reactance at 60 Hz of only about 1300 ohms, meaning that a current of up to 90 mA could still flow through, which seems like plenty to deliver a lethal shock, especially if you’re placing the electrodes right next to the brain.

So in our estimation, this project is not one which should be attempted.  Kids (and adults):  Do not try this at home!



How to Read a Vernier Scale

1944JunePMVernierSeventy five years ago this month, the June 1944 issue of Popular Mechanics carried a lesson in the now almost forgotten art of reading a vernier scale.  With virtually any kind of instrument with an analog display, such as a caliper or micrometer, the vernier scale allows the human eye to make a much more precise reading.

The vernier display consists of two scales.  In the example shown above, the top scale is the main scale, and shows just over 5.3 inches.  (The zero on the bottom scale takes the place of the pointer which would be used on a non-vernier scale.)

The human eye, looking at this pointer, would undoubtedly conclude that the actual measurement is 5.35 inches, since the pointer is about halfway between the 3 and the 4.  But is it really 5.35, or is it 5.34 or 5.36?  You can’t really tell with the naked eye.

But the vernier scale makes eyeballing it easy.  You simply look at the bottom scale, and see which number is exactly lined up (or most closely lined up) with a number above.  In this example, the 6 on the bottom scale is lined up exactly with the 9 on the upper scale.  The number on the upper scale is not important–it’s only important that some number on the lower scale is lined up exactly.  In this case, the 6 means that we add 6/100 inch, meaning that the exact measurement is 5.36″.

Below, we see a vernier dial applied to a caliper.  In the picture on the right, the scales are flattened so that they can be viewed on the printed page.  The idea is the same.  The sleeve scale shows 0.3 inch, plus 0.12 on the thimble scale, since the center line is between 12 and 13.  The 5 on the vernier scale is lined up with the 20, meaning that we add .005 inch.  Thus, the measurement is .3 + .012 + .005 = .3125 inches.

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Radio fans are probably most familiar with the “vernier dial” shown at the left.  This one is available on Amazon and is called a “vernier dial.”  However, the vernier markings which are supposed to be on the tab on top are inexplicably missing.

The vernier scale is named after vernier acuity, the human eye’s ability to detect small differences in the alignment of a straight line.

 



1959 Underwater Speaker

1959MayPM3Sixty years ago this month, the May 1959 issue of Popular Mechanics shows an idea that surprisingly never caught on: underwater music. You’re swimming at the pool and listening to music. But when you dive under the water, you can no longer hear the music. The problem is easily solved by installing a speaker inside the pool. Because sound travels five times as fast in water, “music from the submerged speaker is more true-toned than one mounted in the air.”

And the project is quite simple. All you need to do is purchase a “submergence-proof speaker.” The magazine recommended the University MM-2F (UW), a 25 watt speaker which sold for about $40.

And lo and behold, if you search Amazon for “submergence proof speaker,” one is still available today, although it appears to be marketed toward industrial applications. It is shown here, and the full details are available at this link.  It appears quite similar to the model shown in the magazine.  The price is higher today than it was in 1959, although most of the increase is attributable to inflation.