Category Archives: Radio history

1941 Dictator: The Ideal Gift for the Whole Family!

1941Dictator

By November 1940, Canada had been at war with dictators for over a year.  But this ad invited Canadians “in tune with the times, for Christmas, give a 1941 Dictator, the ideal gift for the whole family!”  This ad appeared 75 years ago today, in the November 28, 1940, issue of the Vancouver Sun.

At some point in the 1930’s, someone at the Hudson’s Bay Company department stores decided that “Dictator” would be a good name for their own brand of radios, most or all of which were manufactured by Dominion Electrohome Industries Limited of Kitchener, Ontario.  Presumably, they had a lot of nameplates printed up, so they continued to use them on early wartime models such as this one.

Both the six tube ($74.50) and eight tube ($94.50) featured pushbutton tuning, and both covered short wave, so I suppose both of them could, indeed, bring a dictator into your living room as you tuned the wartime shortwave bands to listen to the voices of Hitler or Mussolini.

 

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1943 One Tube AC-DC Regen

1943OneTubeACDCIf you were lucky enough to have in your wartime junkbox a dual triode such as the 6C8G, you could turn it into a regenerative receiver suitable for both broadcast and shortwave bands.  This circuit was sent in to the March 1943 issue of Radio Craft by one Leo Silber of Springfield, Mass., who appears to have been a high school senior at the time.  It used one half of the tube as a rectifier, with the other half serving as a regenerative detector. To deliver the filament voltage, the set used a 390 ohm “curtain burner” line cord. With four plug-in coils, the set would cover 500 to 15 meters.

Mr. Silber reported that the set pulled in signals from all over the world. His best DX was apparently logged before the War, KC4USB at Little America.  He doesn’t appear to have been licensed before the War, but the 1949 call book shows him as holding W1NRP.  A 1981 biography is available at this link.

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1955 One Transistor Regen Using CK722

1955CK722Regen

1955CK722AdSixty years ago, the editors of Popular Electronics had been flooded with inquiries after one of the Carl and Jerry stories included a transistorized pocket broadcast receiver, in which Carl and Jerry commented on the size and sensitivity of the receiver. The story neglected to give the brand name, and readers wanted to know what it was. It turns out that the boys were talking about the Regency portable that was featured here previously.

The flood of inquiries convinced the editors that “transistors are here to stay,” and as a result, the November issue began a feature called “Transistor Topics.” It included the receiver shown above, which was sent in by one Mr. R. Zarr of Brooklyn, New York, a one transistor regenerative receiver for the broadcast band, using the venerable CK722 transistor, which was advertised in the same issue for $1.25.

As shwon, the set would tune about 400 kHz of the broadcast band, the exact center of which was determined by adjusting the slug of the coil. The set had about the same sensitivity as a good crystal set, the great advantage being very good selectivity.

The editors noted that by substituting a CK760 transistor, the set could probably be made to oscillate up to about 4 or 5 MHz.

1955CK722RegenSchematic

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1943 Code Oscillator and Regenerative Receiver

1943Regen

Amateur station licenses weren’t being issued during the war, but the FCC continued to conduct exams and issue operator licenses. And there was a big demand for operators, both in the military and commercially, so learning Morse Code would be an important skill in 1943, and the January and March, 1943, issues of Popular Mechanics carried companion projects to assist a student in learning the code. The January issue carried plans for a simple code practice oscillator using a 25A7GT tube which ran on 120 volt house current. The set was billed as a “safety code oscillator,” the safety feature being that both the filament and B+ were dropped down to 25 volts by use of a “curain burner” resistance line cord.

The writer, W9SFW, seems to have realized, however, that the setup wasn’t totally safe. Depending on how the plug was inserted, there was a 50/50 chance that the exposed “ground” connections on the exposed chassis were actually hooked directly to 120 volts. The solution was to plug it in the other way. In the case of the code oscillator, this would be apparent, since the oscillator would make noise even with the key up.

The March issue carried a simple one-tube regenerative receiver, using the same tube and many of the same parts. Since listening to actual code on the air was the best way to learn, this set would allow the builder to tune about 6-11 MHz, frequencies that would have been packed with CW signals during the war. The author notes that “once some code efficiency is obtained, listening-in on actual code signals is the best way to increase your code receiving speed and learn real message-handling procedure that will be of help in service training.

Since unlike the oscillator, the receiver would operate just fine even with the chassis “hot,” the article advises that the polarity of the cord should be tested and then marked. To test it, a light socket was hooked to one of the ground points, with the other side to an actual ground. If the bulb lit up, then the plug was the wrong way and should be reversed. With the correct polarity and the “curtain burner” cord dropping the voltage, the set would be relatively safe.

It should be noted that there’s really no safe way to build this set on an exposed breadboard without the “curtain burner” cord. Even though polarized cords are available, which are a step in the right direction, there’s another problem. One could use a sufficiently large 330 ohm resistor to drop the voltage, but one end of that resistor would still have 120 volts on it. If you do overcome that safety obstacle (by not leaving connections exposed), all of the parts required for this simple set should be readily obtainable. The set uses two variable capacitors, one for tuning and the other for regeneration. As discussed in the article, the exact values are not critical. The coil is wound on a cardboard form. The fixed capacitors are readily available, with the added bonus of the modern equivalents being much smaller than the 1943 versions.

The tube is a dual tube, and in both circuits, half the tube is used as the rectifier.

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Science Fair Idea: Homemade Microphones

1945Microphone0

For the aspiring mad scientist, young or old, the November 1945 issue of Popular Science shows how to make several homemade microphones.  If you’re a student looking for a science fair project, then building your own microphone is probably going to impress the teacher more than a homemade volcano.  While other kids might even put together electronic projects, it’s unlikely that very many of them will put together individual electronic components.  And since most people think of microphones as sensitive and complicated instruments, you’ll probably be the only one to think of it.  You’ll discover that most of them are quite simple to construct, although there’s no need for you to share that little secret with the judges.

1945Microphone1The first design, shown here and in the photograph at the top of the page, is simplicity itself.  It consists of little more than three nails, one resting precariously on top of the other two.  When struck by sound waves, the top nail vibrates, causing a slight change in resistance.

1945Microphone2The second design, shown here, is only slightly more sophisticated.  It is a carbon button microphone, and consists of carbon granules in a small container, such as the cap of a ketchup bottle.  As sound strikes the granules, the resistance changes.  This setup requires a slightly higher voltage, but will give you considerably more audio output.  The carbon granules can be obtained by cracking open a carbon-zinc battery (the cheap kind), removing the carbon rod in the middle, and crushing it up.  A double-button design is also shown for the advanced student.

1945Microphone3A homemade dynamic microphone is shown here.  It consists of a coil of wire mounted between two magnets.  When the coil moves as a result of sound, the microphone becomes a tiny electric generator producing an AC current in time with the sound.  Unlike the earlier designs, which simply varied the resistance, this one requires an amplifier to amplify the tiny current generated.  In 1945, this probably posed a bit of a problem.  But today, you can easily connect it to a cheap audio amplifier such as this one and get plenty of audio to impress the judges.  You can also simply plug the microphone into the microphone input of a computer.  Another variation of the dynamic mike, also described in the article, is the ribbon mike, which substitutes a thin ribbon of foil for the diaphragm.

1945Microphone4The final, and most advanced, microphone described in the article is shown here.  This is the piezoelectric or crystal microphone, which your teacher would probably tell you is impossible to make at home.  But your teacher is wrong, as shown by this 70 year old article.  You simply grow yourself a suitable piezoelectric crystal and arrange it as shown here.  While it might sound intimidating to grow a crystal, this is actually the same thing your less advanced peers are doing by making rock candy as their science fair entry.  Instead of using sugar to make the crystal, you use Rochelle Salt (potassium sodium tartate). Your chemistry teacher probably has a dusty bottle in the lab. If not, you can simply buy some on Amazon.  Like the dynamic microphone, this one is hooked up to an audio amplifier.

If you’re a student, your teacher is probably tired of homemade volcanoes, potato clocks, and other scientific curiosities that he or she has seen a hundred times before.  Your homemade microphone(s) will be most impressive.  And even if your school days are behind you, making these simple microphones will be quite rewarding.

 

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Radio Scouting, 1940

A sampling of the author's QSL's.

A sampling of the author’s QSL’s.

Seventy-five years ago this month, the November 1940 issue of Boys’ Life carried a one-page plug for Amateur Radio entitled “DX Hams Do Get Around.” The author, Larry Le Kashman, W2IOP, starts by explaining how hams can “hold a conversation annihilating time and space by the touch of a switch,” and goes on to explain the licensing requirements. After a rundown of things like call signs and Q-signals, he moves to some of the exciting things that happen on Ham Radio, undoubtedly of interest to young scouts who wanted to Be Prepared. He tells a couple of tales (lacking in many details) such as that of a ham in California who was working a station in New Zealand until the latter suddenly left the air. The worried Californian managed to make contact with another station in the same town who investigated. The first New Zealander had been overcome by gas, and the quick actions of the California ham saved his life. Another unnamed station somewhere in the Midwest “was held up by thugs while his phone transmitter was on the air. The station he was talking to make a long distance telephone call and the distressed ham was rescued in short order by the police.”

Le Kashman included a few more corroborating details when talking about what hams did during hurricanes and floods. (However, many of the corroborating details for a flood “last winter” sounded suspiciously similar to what had actually happened in 1936.)  But the exact details were less important than the compelling story the article told:

Perhaps you were wondering what was happening in the cold Eastern states when flood waters started rising last winter. Had you turned on a short wave receiver you might have heard the first sharp signal pierce through the night with a frantic appeal–“QRR QRR,” the land SOS shattered the ominous stillness of the black night. Amateur activity ceased in an instant–from coast to coast ears were strained listening to the troubled frantic calls for help. With no wires, no roads, no power, the stricken cities were relying upon battery operated amateur stations. News services, starving for stories called on the radio amateurs.

Endless hours passed as the drama unfolded. At 2 A.M. the first flood missages came through. At 3:05 W8WBH, operating from the Pittsburgh area,  wired frantically for aid. All wires were down. Snatches of messages came through the interference, only to end in a tragic blurred whine, as power failed. Cold, gray dawn broke on operators racing against time. State after state went under the rushing, conquiring, relentless deluge, and their only link with the outside world was the isolated hams. An ominiously curtailed message from New Cannan read, “WATER 3 FEET STILL RISING.” At 10 A.M. a plane missing between Springfield and Albany was reported safe.

The author concludes that this “is the kind of stuff that makes amateur radio!”  And it turns out that the author knew a thing or two about amateur radio.   Born in 1921, Larry LeKashman was only about 19 when he penned this article, but he was already a prominent amateur. Until his death in 1978, he had held calls W2IOP, W8IOP, W9IOP, and W2AB. His career included serving as an editor of CQ magazine, and employment by RCA, Lafayette, and Bogen Electronics. In the 1950’s, he was the vice president of sales at Electro Voice, a position he held until his death.

The year before the Boys’ Life article, 1939, he had taken the top place in the ARRL CW Sweepstakes,  a feat he repeated in 1948, 1949, 1953, 1957, 1959, 1960, and 1963.  The connection with Boys’ Life isn’t suprising, since the National Eagle Scout Association database reveals that he became an Eagle Scout on September 11, 1934, in Troop 1, Oakland, Maine.

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Amateur Station 9CXX, 1925

9cxx1925

Ninety years ago this month, in an article entitled “Riding the Shortwaves,” Radio Age (November 1925) carried this photo of the efficient, but surprisingly simple, amateur station of 16 year old 9CXX, located at 514 Fairview Drive, Cedar Rapids, Iowa.  The article was an introduction to amateur radio, and pointed out that stations such as the one shown here could pull in stations from around the world with a three-tube receiver, “while broadcast listeners are using receivers with five to nine tubes.”

The article focused on the station of young 9CXX because in the summer of 1925, the then-15-year-old amateur had come to prominence by being the only station who managed to keep in touch with WNP, the station of the MacMillan Arctic expedition aboard the Bowdoin.

9cxxRxA schematic of the 9CXX receiver is shown here.  It was also followed by two stages of audio amplification, which are not shown.  As can be seen, the circuit is very simple.  While the receiver is regenerative, it has no regeneration control.  Instead, the regeneration was adjusted by reaching in and carefully moving the two coils.  And in order to avoid capacity effects, the tuning condenser (which had to be of the highest quality, according to the article) had no type of vernier dial.  Instead, the shaft had an eraser mounted at the end which was used to carefully tune the set.  With the two stages of audio, it was reported that the Arctic expedition had come in loud and clear to the point that the operator could remove the headphones and hear the voices of the crew throughout the room.

9cxxTx

9CXX had two transmitters, shown here.  The one on the right put out 50 watts, and the one on the left 1000 watts.  The high power transmitter used 4000 volts on the plate.  When the power supply caused the house lights to dim, the 15 year old installed a new 20 amp circuit, running a heavy cable up from the house’s service box.  The contacts with the Arctic were made on 15, 16, and 21 meters.  He routinely made contact with Australia, usually on 40 meters.

When the young ham made his contacts with the Arctic, it was with antennas installed in a tree.  “Having built a dream house, on Colonial lines, his parents were thinking more of architectural beauty than of scientific achievement, and poles are likely to be unsightly.  But since their son established his remarkable record there have been erected on the roof two thirty-foot masts.”

If the call sign looks vaguely familiar, that’s because it was held by someone who went on to continued prominence in radio, Arthur A. “Art” Collins, who later held the calls W9CXX and W0CXX.  Collins built is first radio, a crystal set using a Quaker Oats box, at age 9.  By 1923, after attending a two-day radio course at Iowa State University in Ames, he had his amateur license.  In 1931, then married, he decided to turn his hobby into a business and started Collins Radio in his basement at 1620 Sixth Ave. S.E., Cedar Rapids.

He formally incorporated the company in 1933, and by 1954, the company, now Rockwell-Collins, had sales of $80 million. The company remained a leading producer of broadcast transmitters until the 1970’s, and also produced amateur equipment most of that time.  Along with fellow  amateur General Curtis LeMay, Collins played a large role in the adoption of SSB voice by the U.S. military.

A good biography of Art Collins can be found at WA3KEY’s site.

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Battle of Fort Rivière, 1915

Battle of Fort Rivière. USMC image.

Battle of Fort Rivière. USMC image.

A hundred years ago today, November 17, 1915, the United States fought the Battle of Fort Rivière.  Chances are, most Americans have never heard of this battle, even though it resulted in three Medals of Honor being awarded to U.S. marines or sailors.

Among the Medal of Honor recipients was then-Major, later General Smedley Darlington Butler, who led the U.S. forces in the battle, which was part of the U.S. occupation of Haiti, which had begun on July 28, 1915.  The occupation had been motivated by two factors.  Those factors overlap a great deal, and historians have debated the relative importance of each.  First of all, there was a need to protect U.S. commercial interests in Haiti.  The country had potential with agriculture, minerals, and ports.  American interests were hampered by, among other things, the fact that foreigners were not allowed to own property.

The other concern was German influence in the Western Hemisphere, and the United States viewed Germany as having too much influence in Haiti.  While the German population was quite small, it did have a very great commercial influence, since a very large portion of the commercial activity was controlled by German families with strong ties to the old country.  Also, the Germans were more willing to marry in to prominent Mulatto families, thus skirting the property ownership laws.

President Wilson sent in the marines in July, and the largest battle took place on November 17 as U.S. sailors and marines stormed an old French fort where the peasant rebels were holed up.  The battle against the poorly equipped rebels was over quickly.  Over 50 rebels were killed.  The only U.S. casualty was a marine who had two teeth knocked out by a rock thrown at him by one of the rebels.  While a few later skirmishes took place, this was the decisive battle.

Under the occupation, Haiti adopted a new constitution written by then-Secretary of the Navy Franklin D. Roosevelt.  It gave U.S. officials more or less absolute veto power over acts of the Haitian government, and also guaranteed foreigners the right to own property.

The occupation did have the result of modernizing Haiti.  For example, Port-au-Prince became the first location in the Caribbean to have an automated dial telephone system.  Also, Haiti had radio broadcasting as early as 1926, as reported in the February 26, 1927, issue of Radio World.

General Smedley Butler

An adult male looking to the right in a military uniform; military ribbons are visible.

General Smedley Butler. Wikipedia photo.

As a result of the battle, Butler received the first of his two Medals of Honor, and he went on to become, at the time, the nation’s most decorated military hero, and made a name for himself two other times off the battlefield.

The first was in in 1934 when he testified before the House Special Committee on Un-American Activities, revealing what came to be known as the “Business Plot.”

He testified that he had been called upon by business leaders to lead a march of veterans on Washington, at which point he would stage a coup against President Roosevelt. Roosevelt would be kept on as a puppet figure, with Butler wielding most of the power. Butler had been a key figure in earlier marches by veterans, was respected as a military leader, and the conspirators, most of whose names were never publicly revealed, planned to use Butler as their puppet, so he testified.

The Committee, and the American press, generally dismissed Butler’s testimony as an implausible conspiracy theory.  The phrase “tinfoil hat” hadn’t yet been coined, but if it had, it probably would have been applied to Butler.  Compounding the problem was that Butler seemingly hadn’t named any names, although this wasn’t entirely true.  He had named names, but since most of his allegations amounted to hearsay, the Committee had refused to make them public.

The most plausible explanation, it seems to me, is that there was indeed a conspiracy to overthrow the government, and that Butler was approached to lead it. It doesn’t appear that he had any motive to fabricate the story. However, it also seems likely to me that the conspiracy wasn’t as large as he was led to believe by those who approached him.

In 1935, based upon his experiences as a career military officer, Butler published “War is a Racket,” a widely-distributed pamphlet in which he argues that war is, indeed, a racket, which he summarized as follows:

War is a racket. It always has been. It is possibly the oldest, easily the most profitable, surely the most vicious. It is the only one international in scope. It is the only one in which the profits are reckoned in dollars and the losses in lives. A racket is best described, I believe, as something that is not what it seems to the majority of the people. Only a small ‘inside’ group knows what it is about. It is conducted for the benefit of the very few, at the expense of the very many. Out of war a few people make huge fortunes.

Butler’s recommendation was to make war unprofitable by conscripting soldiers only after conscripting capital.  Of course, the naysayers would say that this runs roughshod over private property which, of course, it does.  But conscription of soldiers also runs roughshod over their own personal liberties, so the idea doesn’t strike me as too farfetched.  Butler also recommended that the declaration of war be done not by congress, but by a referendum of those subject to service, and also a restriction of the military to self-defense only.

The book is available online at numerous places, including archive.org.

 

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1890’s Edison Phonograph

November1955RadioNewsCover

Sixty years ago this month, Radio News, November 1955, carried this photo recreating an American living room sixty years before that, in the 1890’s.  The photograph was staged by NBC, and the photo taken by Jack Zwillinger.  It features an Edison Talking machine.

We’re at a distinct advantage over those in 1955, since we have the capability of listening to many of those early recordings.  In 1955, the fragile cylinders would have been too precious to play on the original equipment.  Fortunately, many of these recordings, some well over a century old, have been digitized and made available on the internet by the UCSB Cylinder Audio Archive and others.  The Library of Congress also has thousands of recordings online, although most of their collection are discs recorded after the turn of the Twentieth Century.  To get an idea of what the woman in the photo might have been listening to, this link will allow you to play The Last Rose of Summer, an 1894 Edison recording.

While the ornate horn is obviously an upscale version of the instrument, a phonograph was already becoming affordable to Americans in the 1890’s, and the scene depicted here would not have been extraordinary.  By 1900, a basic Edison machine could be had for about $10, with the cylinders going for about $5 per dozen.

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1970 One Tube Superhet

1970OneTubeThe plans for this one-tube receiver appeared in the Fall-Winter 1970 issue of Electronic Hobbyist, a special issue put out by the publishers of Elementary Electronics.  Even though it’s a one-tube set, it’s really the functional equivalent of the “All American Five” five-tube receiver, whose reign was just ending about that time.  The one tube employed was a 6M11, a triple tube consisting of two triodes and a pentode.  The three sections of the tube acted as local oscillator, IF amp, and AF amp.  The detector was a 1N34 diode, and the rectifier was a solid-state bridge rectifier.  So as one-tube broadcast radios go, this is about as sophisticated as they get.

As revealed by the picture, the author concedes, “we didn’t attempt to make the front panel an artistic masterpiece. You may want to make yours more attractive by restyling the dial plate and /or the speaker grille.”

“New old stock” examples of the tube are available at a reasonable price.  The parts that might prove to be unobtanium are the loopstick antenna, oscillator coil, and IF transformer.  If you have an old AA5 that’s beyond repair, the best course of action might be to scavenge them from it.

1970OneTubeSchematic

 

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