Category Archives: Radio history

KIRO Seattle; Milton Shaw, 1917-1944

1941Dec29BCEighty years ago today, the December 29, 1941, issue of Broadcasting showed Private Milton Shaw of Cleveland, Georgia, standing guard over the 50,000 watt transmitter of KIRO, Seattle, sited on Vashon Island. The soldier was one from the 41st Division. The magazine claimed that the station was “located in the center of a large colony of Japanese nationalists.” The magazine noted that the station was the only 50,000 watt station north of San Francisco and Salt Lake City.

free-vector-poppy-remembrance-day-clip-art_106032_Poppy_Remembrance_Day_clip_art_smallAccording to this source, Shaw was killed in Action in New Guinea on June 17, 1944, and his remains are buried at Oakwood Cemetery, Oakwood, Georgia.



Worldwide TV: 1951

1951DecPMSeventy years ago this month, the December 1951 issue of Popular Mechanics carried a feature with the byline of RCA Chairman of the Board David Sarnoff discussing the prospects of international television. He predicted that before long, viewers would be able to bring exciting events from distant lands to their armchairs with a flick of the dial, all at the instant they’re taking place.

He outlined the ways this might happen, but interestingly, he fails to mention the technology that did make it happen, namely orbiting satellites.

His most promising idea is shown above, namely a network of microwave relays about 20-50 miles apart. This network was already taking shape in the US, and Sarnoff pointed out that it could easily be expanded from Patagonia to Alaska. And since it was only 40 miles acroos the Bering Strait, there was no technological reason why the network couldn’t be thus extended into Eurasia, and from there to Africa. He notes that there were plans for a telegraph land line along the same route 90 years earlier, which was abandoned only after the success of the transatlantic telegraph cable.

Another idea for connecting America and Europe was a string of artificial islands in the Atlantic, 200 miles apart, each with a 1000 foot tower.

We’ve previously mentioned the idea of stratovision, namely, using aircraft both to broadcast and relay programs. Sarnoff hinted at a possible expansion of this system to link America and Europe. He noted that there were already enough commercial flights flying the route, and that if these planes were fitted with television relays, they could provide a permanent microwave link across the Atlantic.



Science Fair Idea: Electrostatic Precipitator

1946DecPS1946DecPS2Seventy-five years ago this month, this young woman undoubtedly took home the blue ribbon of the 1946 Science Fair with this experiment in which she constructed an electrostatic precipitator to fight air pollution.  In the photo above, a column of smoke is rising.  But the moment she flips the power switch on her precipitator, the smoke ceases.  An electrostatic precipitator, known at the time as a Cottrell precipitator after its inventor Frederick Gardner Cottrell, removes particulate matter from the air through an electric charge, but does not affect the flow of gas. The same principle is used in home air purifiers such as this:

In the 1946 experiment, a column of polluted air passes through a mailing tube, where it passes through a high voltage electric field. Particulate matter clumps together as a result of the electric charge, and falls to the bottom of the tube.

We enjoy providing inspiration for projects such as these, and we hope modern school children can do the same experiments. And for this project, your young scientist will need the following items. Where available, we have provided links to Amazon:

As you see, Amazon no longer has all of the needed parts. The Model T spark coil is apparently out of production. And while this young woman had no problem bringing a pack of Chesterfields to school and nonchalantly lighting one up in the science classroom to show off her invention, it’s no longer 1946. If a kid did that today, they would probably get expelled. So if Junior wants to do this experiment today, some modification is necessary.

Fortunately, as long as your young scientist has some creativity, substitutions shouldn’t be a problem. In place of the cigarette, the original 1946 experiment allows for the use of an incense stick, and as long as Junior has the teacher’s permission, this shouldn’t be a problem.

The Model T spark coil, however, is a bit more problematic. The spark coil from a Model T was known as a trembler coil.  The device was a transformer. To be able to operate with DC, the coil operated in interrupter: When voltage was applied to the coil, the magnetic field opened the contacts of the interrupter, which turned off the coil. With the coil off, the contacts closed, allowing the coil to re-energize. The result of this on-off action was an alternating current, and the voltage of this alternating current was stepped up to thousands of volts with the transformer.

The Model T spark coil remained in production for many years after the last Model T rolled off the assembly line, and many of them found their way into things other than cars. When this experiment was published in Popular Science in December 1946, there was apparently no question that if you wanted a Model T spark coil, that finding one wouldn’t be a problem. One popular use of the coil in the early days of radio was for use in a spark-gap transmitter.

But if you walk in to the parts counter of your local Ford dealer today, they probably don’t have them any more. (On the other hand, there are still Model T’s on the road, and if you want to buy a new spark coil, they are still being made, but they’re probably too expensive, such as this one.)

The advanced student should be able to build their own induction coil. They will need a transformer and a method of interrupting the current. Experimentation with a filament transformer and mechanical buzzer will probably prove fruitful. Our earlier post describing a spark coil should give the advanced student enough information to construct one that is essentially identical to the Model T version.

The school might already have the equivalent stashed away in the back room of the science lab, or you could convince the teacher to spend some of the science budget on one of these:

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1951 Raytheon Model RC-1720 Starlight

1951DecRadioRetailingShown here from 70 years ago is an ad for Raytheon Television’s deluxe offering, the model RC-1720 “Starlight” set. According to the ad, the set was famous for fringe area performance, and it boasted a 17 inch picture tube, along with room-filling volume from a 10 inch speaker.

The set retailed for $369.95, which was down from the previous price of $469.95. That price included the federal excise tax, as well as a one year warranty. In addition to the TV, the set included an AM radio (but no FM), and a three speed phonograph.

In 2021 dollars, the price of the set works out to almost $4000, according to this inflation calculator.  The ad appeared in the December 1951 issue of Radio & Television Retailing.



1946 Modern Crystal Set

1946DecRadioCraftThe plans for this “modern crystal set” appeared in the December 1946 issue of Radio Craft, having been sent in by one W.J.E. Spain of Toronto. The author reported that the set was both selective and sensitive. He had six local stations in his area, ranging from 1000 to 50,000 watts, including a police station, and could pull in all of them with no interference between stations. All had good volume on headphones, and four stations were strong enough to operate a horn type speaker, with a 75 foot antenna.

At night, WLW Cincinnati and WENR Chicago came in like strong locals. The Buffalo stations were also heard regularly at night.

The switch marked S/B was used for selectivity. In the S position, the set was very selective, and in the B position, tuning was broad. He tuned with the switch in the B position, and then switched to S to cut out interference. Tuning was accomplished with S1 and the variable condensers, one of which was used for fine tuning.

The crystal was a 1N23, a germanium crystal which had been used as mixers in radars. They appear to be available today, or other diodes such a 1N34 would probably provide good results. For ideas on sourcing parts, see our crystal set parts page.



Home Study Courses Courtesy of Uncle Sam

1971DecPEThe December 1970 issue of Popular Electronics provides some good advice to anyone seeking to learn about any subject. They were talking about electronics, but the same general advice applies to any field.

The magazine began by noting that money spent on a formal education is a generally wise investment. But in many cases, the student might not want to commit to a formal education. Among other things, formal education normally costs money.

But even though it has built-in disadvantages, a course of informal “go-it-alone” self study can provide a firm understanding, at a minimal investment. In 1970, the monetary investment came to $18.55. But in the internet age, that cost is essentially zero.

The magazine warned of simply buying a book and hoping that it would provide the correct study material, since it might not provide a broad enough scope. But the magazine noted that there were inexpensive books that were well designed for the purpose, namely, training manuals used by the military, and for sale at a nominal cost by the Government Printing Office. It went on to list those books recommended for a basic course in electronics, and the total cost was only $18.55.

Today, most of those same books are available at no cost on the internet. Specifically, here they are, with links to Google Books or other sources:

Of course, these texts are all now more than a half century old. But the basic theory is unchanged, and that course of study would provide an excellent background, even though the student might learn a bit of archaic material in the process. With minimal research, the interested student could update the course materials and include modern texts in electronics–or modern texts in any other subjects.

Today, it is quite possible to get a good university education and spend hundreds of thousands of dollars in the process. If you do this, two things will happen. First, you will presumably become a smarter person, because you have learned the material that was taught. And you will also get a handsome piece of paper from a prestigious institution attesting to the fact that you have learned the material. That piece of paper is very good to have. Indeed, if you want to do some things, such as perform surgery, then having that piece of paper is absolutely required.

But you can gain all of the knowledge without the piece of paper. Even though I have an advanced degree, I’ve come to the conclusion that for many, the piece of paper isn’t particularly valuable, even though the knowledge is.

If you pay tuition at a university, you will take courses, and during those courses, you will be given a list of books to read, and you will attend lectures explaining those texts. The books have always been available for purchase, or you can read them at the library. And in many cases, the lecture is available online for anyone to view, whether or not they have paid tuition.

If you pay tuition, you also have the privilege of showing up at the professor’s office hours and asking questions. But in my experience, students never do that.

In short, my advice to many students is that perhaps paying tuition isn’t really in your best interest any more. You can gain the knowledge for free. At that point, you’ll need to figure out a substitute for the piece of paper attesting to your knowledge.

In 1970, one suggestion that Popular Electronics made was to obtain your FCC Radiotelephone License, preferably the prestigious first class license. That option is still available, although it’s less prestigious, and the license is now called the General Radiotelphone Operator License (GROL). In fact, I’m the author of a study guide to earn that license.

The GROL is still the ticket to a handful of jobs in electronics, but in many cases, it’s unknown to employers. But there are probably other methods of proving your bona fides. And before long, other people like me, who have advanced degrees and a stake in higher education, are also going to start coming to the realization that maybe that fancy piece of paper is overpriced. And eventually, someone is going to come up with a less expensive alternative piece of paper. In many industries, that piece of paper probably already exists.

In short, my advice is to consider whether self-study might work for you.  If done right, you can learn almost as much, or as much, as students undergoing formal education.  And if you’re smart enough to do that, perhaps you are also smart enough to figure out a way to prove it, even without that handsome, but expensive, piece of paper.



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1921 Transatlantic Tests

1922JanQSTx
1921Dec12NYHeraldAmateur Radio signals first crossed the Atlantic 100 years ago the night of December 11/12, as documented here in the December 12, 1921, issue of the New York Herald.

An attempt the year before had been unsuccessful, and in 1921, the American Radio Relay League pulled out all the stops to ensure success. In addition to European operators who would be listening in, American Paul Forman Godley, 2ZE, was sent to England with the latest in American receiving equipment. He set up in a field at Ardrossan, Scotland, with only a tent to house himself and the receiver.

Transmissions from North America followed a pattern. Between 7:00 and 9:30 PM Eastern Time, all stations were invited to send, with a 15 minute period designated for each call area. These stations simply called TEST and their call sign. Starting at 9:30 until 1:00 AM, about two dozen pre-selected stations took turns calling. Each of these stations sent a five-letter cipher which had been given to them in a sealed envelope.

My personal connection to the tests is the fact that one of these stations, 9XI at the University of Minnesota is one I personally operated many times, and of which I served as trustee for several years. In those early years, there was a fuzzy line between amateur stations and broadcast stations. At some point there was a split, and the broadcast side of 9XI became licensed as WLB, and later as KUOM, under which call it still operates.

1921DecQST1Amateur station 9XI became 9YC, later W9YC, and after the war, W0YC, the call it held when I was a member and later the licensee. With the exception of 6XH at Stanford University in California, 9XI was the furthest west station participating. It was not heard in Europe, but the station sent the cipher SFLJT on 300 meters (1000 kHz) using CW. The transmitter was undoubtedly the one shown at left, described by Prof. Cyril M. Jansky, Jr., in the December 1921 issue of QST.

Numerous stations were heard the night of December 11, the most notable being 1BCG, as reported in the news clipping above. The signals from Connecticut were heard not only in Britain, but also on the Continent. A full message was picked up by Godley from the station at 3:00 AM GMT, or 10:00 PM in America.

Through special arrangements with the Marconi Company, word was sent back to America on the high powered commercial station MUU. Even though Marconi used automated high-speed code, it allowed this message to be sent by hand so that it could be copied by Amateurs in America directly. The message was acknowledged by Marconi’s American station, WII, also hand keyed for the occasion, to make sure that the word was heard throughout North America that the tests had been successful

Back in Hartford, ARRL officials were gathered around the longwave set tuned to MUU. According to the account in the February 1922 issue of QST, the air was so thick with tobacco smoke that it was hard to see how a signal could get into the room.

Today, communicating across the Atlantic is a pretty routine occurrence. We’ve learned over the years that even higher frequencies work even better than the ones used in 1921–most of which were in what we today consider part of the AM broadcast band. When I operate portable from a park using 5 watts, I made numerous contacts with Europe. It’s pretty easy now, and it’s something that’s been going on for a century now.

Various events will be taking place this weekend to commemorate the event.  Most of these are listed at the ARRL website.  In particular, I want to do my best to listen to a recreation of 1BCG’s transmitter, and you can read details of that event at this link.



Dr. Philip Weintraub, W9SZW

1951DecBLSeventy years ago this month, the December 1951 issue of Boys’ Life carried a feature entitled “SWLing is Swell,” pointing out all of the fun that can be had by shortwave listening, primarily to the ham bands. The article began with an incident shown in this dramatic illustration, of the robbery of dentist and ham radio operator Dr. Phillip Weintraub.

The two well-dressed robbers barged into Dr. Weintraub’s office, in which he luckily had his ham station set up. In a stroke of luck, he was in the middle of transmitting, and left the transmitter turned on while the robbery was taking place.

The thieves were disappointed that the dentist had no money other than five dollars in his wallet, and there was no gold on the premises. The tied him up, stashed him in a closet, and departed.

As luck would have it, however, the dentist’s wife, Evelyn Weintraub, was at home, and just happened to be listening to her husband’s station. She quickly called the police, and then raced to the office, arriving before the first squad car. She pounded frantically at the closet door, and one of the responding officers was able to take the door off its hinge. The police sergeant later told her, “you’d be a widow right now if you hadn’t heard those holdup men over the radio and reported it.”

The story sounds a bit suspect, but there’s enough corroboration to say that it is probably true, and probably took place in about 1937. There was indeed a Philip and Evelyn Weintraub in Chicago, as shown in the 1940 census.  Indeed, his house at 3252 W. Victoria Street is a Chicago landmark complete with its own Wikipedia page.

And the 1952 call book shows Philip Weintraub listed twice, once as W9SZW at 3252 Victoria, and as W9TMQ at 201 South Pulaski Road.  That address is currently a vacant lot, but it’s in a commercial district, and it seems like a plausible spot where a dental office would have been located 70 years ago. The callbook also lists a Royd L. Weintraub as being licensed as W9PZO at the home address. In the 1940 census, Royd is listed as being 2 years old, so he would have been about 14 years old in 1952. You can see the younger Weintraub’s biography at this link.

Thus it appears the doctor had a secondary station location licensed at his office, and the story sounds more plausible. Indeed, the incident is recorded in more detail in the 1941 book Calling CQ by Clinton DeSoto, W9KL, which includes much the same story, with the added detail that Weintraub was in QSO with W9JFF or (or possibly W9JJF), who was “frantic but impotent,” as his heart pounded madly listening to the drama unfold. DeSoto’s account notes that the doctor stayed late at the office, having told his wife, reportedly a dark haired sultry beauty, that he would be late, and invited her to listen in, as she often did.

The other reference I found to this story was a brief mention in the July 1937 issue of Radio News.  Apparently, WMAQ ran a midnight program consisting of dramatic reenactments of “important events in amateur radio,” sponsored by Hallicrafters. The magazine shows a reenactment of the holdup, and notes only that “Dr. Weintraub was saved due to the presence of a transmitter in his office.”

I would stay up until midnight to listen to that program, and it’s a shame that it’s no longer on the air.



1946 Stromberg-Carlson Ad

1946Dec9Life

We’ll just cut to the chase. If you love your kids, then you should buy a Stromberg-Carlson radio. This ad appeared in Life magazine 75 years ago today, December 9, 1946.



Meissner Model 10-1163 Receiver Kit

1941DecRadioNews1

This handsome receiver kit was advertised in the December, 1941, issue of Radio News.  Meissner Manufacturing of Mt. Carmel, Illinois, was a manufacturer of components, and also sold manufactured radios and kits. Shown here is a three-tube receiver, but it was also offered as a one or two-tube version. After mastering the one tube set, it was possible to upgrade. The three-tube set, model 10-1163, sold for $5.15, not including battery, tubes, and headphones. The one-tube set, model 10-1161, sold for $3.30, and the two-tube model, 10-1162, was priced at $3.96.  They came with a coil for the standard broadcast band, and additional coils for the short waves were available.