Radio Stamp Fad of 1925

1925FebRadioNews1925FebRadioNews2A hundred years ago, this gentleman is enjoying the latest craze in the radio world, namely, collecting stamps issued by stations around the country. He purchased the album from the Ekko Company, 111 West Monroe St., Chicago for $1.75. It contained hundreds of spots for stamps for various stations. It also included cards to be sent to the stations with reception reports, along with a spot to place a dime. If the reception report checked out, the station would send you a stamp for your album. Chances are, they made a modest profit, thanks to your dime.

As your album filled up, you could show off to your friends what stations you pulled in, with the proof right in front of their eyes.

The cover is from the February 1925 issue of Radio News, which carried an article discussing the system. It also just happened to have an ad for Ekko, from which you could order your album.



1955 Giant Loop Crystal Set

1955RadioTVExp
This young woman has been collecting Social Security for a few years now, but 70 years ago, she was pulling in a program from the proverbial strong local station, thanks to this handsome giant loop crystal set, described in the 1955 volume of Radio-TV Experimenter.

Thanks to the large loop antenna, the set did not require an external antenna or ground for those strong stations. The loop consisted of 85 feet of wire around at 14 x 24 inch frame. Attention was given to finishing the wooden frame to make the object an item of beauty as well as utility.

The set could be rotated for best reception, and for added sensitivity (but reduced selectivity), it could be placed near a floor lamp to inductively use the power lines as an antenna. As you can see, this listener was quite impressed with the design.

1955RadioTVExp2



Lola Lane’s Majestic Model 3C70, 1940

1940FebRadioTodayActress Lola Lane is shown here doing some SWL’ing with her Majestic model 3C70. The cabinet is hand-rubbed sliced walnut. But more importantly, the seven tube chassis inside covered three bands (550-1700 kHz and 2.1 – 22 MHz) and included a loop antenna.

The photo appeared 85 years ago this month in the February 1940 issue of Radio Today.



1965 CB Sportscar Mobile

1965FebPESixty years ago, there was no better way to impress the chicks than installing a CB radio in your sportscar, as demonstrated here by one Dave Hallow, KLK6733. We have a hunch, however, that he’s actually shown here with his kid sister. In any event, the car was an Austin-Healy Sprite, and Hallow needed to figure out how to install a CB without disturbing the lines of the car. He accomplished this, first, by replacing the existing AM antenna with an Antenna Specialists M-103 combination AM-CB antenna. Since there was no room under the dash, he installed an E.F. Johnson M-III transistorized transceiver under the dash, along with a Johnson suppression kit to eliminate interference.

He’s shown wearing a Telex DYB-10 boom microphone headset to allow hand-free communication. The photo appeared in the February 1965 issue of Popular Electronics, which noted that the headset provided the ability to receive clear signals above 40 MPH. Perhaps regulators hadn’t gotten around to re-writing traffic codes yet, but a dual headset for the driver would be illegal in most states today, since it doesn’t allow road noises to be heard. These days, single-ear Bluetooth headsets, complete with noise-cancelling mike, are available.

We asked ChatGPT to write a story based upon this picture.  I don’t think we have to worry about job security–just yet.  But here’s ChatGPT’s take on it:

The Radio Roadtrip

In the summer of 1965, young Tommy had a dream–to make the ultimate road trip using nothing but his wits, his radio, and his dad’s old convertible. His little sister, Sally, wasn’t about to be left behind, even though she wasn’t quite sure what “ham radio” even meant.

“Are you sure you can drive this thing?” Sally asked, gripping the side of the car as she climbed in.

Tommy, adjusting his oversized headset and pushing his glasses up the bridge of his nose, gave her a confident nod. “Of course! Well… kinda. But that’s not the point. The point is, we’re gonna talk to people all over the world—while driving!”

Sally giggled, excited despite herself. “Like astronauts?”

“Exactly! Or people in Australia! Or maybe even spies! Who knows?” Tommy grinned as he flipped a few switches on the makeshift radio setup he had wired into the dashboard. The soft crackle of static filled the car, and then a voice came through—

“CQ, CQ… this is W6XYZ. Anyone out there?”

Tommy’s eyes widened. He quickly grabbed the microphone. “W6XYZ, this is Tommy—uh, I mean, this is K0TOM, mobile unit, coming in loud and clear!”

Sally clapped her hands. “It works! It really works!”

Their adventure had begun.

Would they make contact with a scientist in Antarctica? A pilot flying high above the clouds? Or maybe even a fellow kid with a radio of their own? One thing was for sure—this was going to be a summer to remember.

 



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1925 Emergency Foot Bridge

1925FebSciInvBridgeA hundred years ago this month, the February 1925 issue of Science and Invention gave these self-explanatory plans for constructing an emergency foot bridge. It had the advantage of being able to use it as you constructed it, since you pushed each new section into place.

Each support was a pair of jumping poles. You would form them into an “X” shape, and then push them out ahead. Perhaps some student will be inspired to turn this into a science fair project. Or perhaps a scout looking for a good pioneering project might be inspired. (If the water below is deeper than ankle-deep, then the current Guide to Safe Scouting calls for participants to wear a life jacket.)



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Laser Safety: 1970

1970FebPEThe December 1969 issue of Popular Electronics carried the plans for a 0.5 milliwatt laser. The magazine noted that there was a lot of interest in making such a device, and there were finally parts on the market to make one that met two important criteria: It had to be inexpensive enough for experimenter hobbyists, and it had to be safe. They deemed the 0.5 milliwatt device to be safe, given some precautions, and the whole project could be built for under $50.

The illustration above appeared in the February 1970 issue, and it depicted how the magazine viewed a few of its readers. In summary, they wanted to burn holes in things, and they wrote in to the magazine asking for plans to do that. In response, the editors made clear that they had no plans to do such a thing. To cause destruction to something, the laser would require a few watts. But eye damage could easily take place at just a few milliwatts. The 0.5 milliwatt laser was safe, but more powerful units were not, so the magazine didn’t want to be involved. “Out of responsibility and concern for our readers, POPULAR ELECTRONICS cannot suggest or recommend a laser of any higher strength than the one described in the article.”

For the young mad scientists, it’s probably possible to find dangerous lasers on eBay, but we don’t plan to help, either.  On the other hand, you can get safe low-powered laser pointers on Amazon.



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How to Make a Pressman’s Cap

Screenshot 2025-01-30 11.16.41 AMWe know our readers pretty well, and we’re almost certain that when they watch an old movie showing a newspaper printing plant, they notice that the pressmen are wearing hats made out of folded newspaper. They also wonder how to make one.

If you fit in that category, you are now in luck, because you have access to the February 1940 issue of Popular Mechanics, which reveals on page 283 exactly how it’s done. It was sent in to the magazine by one W.R. Greer of St. Paul, MN, whom we hope didn’t get in trouble for revealing this trade secret.

For the sake of categories, we decided to place this one in “science fair ideas.”  For a last-minute project, this one answers the scientific question of, “can durable head wear be constructed from newspaper.”  For similar ideas, we’ve previously shown how paper can be used to construct boxes, and even expedient winter footwear.



1945: Keeping Your Name Before Customers

1945FebRadioRetailingEighty years ago there was still a war going on. But people knew that it wouldn’t last forever, and there was a pent-up demand for consumer products like radios that had been unavailable for the duration.

The cover of the February 1945 issue of Radio Retailing reminded dealers of the importance of keeping their names in front of consumers. When the war ended, and products were available, you wanted them to come to you to buy them.



1940 Homemade Batteries

Eighty-five years ago, Britain was at war, and that meant shortages of many things, including flashlight batteries. Undaunted, many Britons took to making their own, and the February 1940 issue of Practical Mechanics showed them how to do it.

Screenshot 2025-01-23 9.14.31 AMThere was a learning curve involved, but the magazine assured readers that the task was well within the capabilities of amateurs. The costs of materials were low, and once you were set up, you could laugh at the Nazis trying to deprive you of batteries.

The article pointed out that filling the cells, at least initially, was a messy process. But once you got into a routine, it was relatively easy. The article suggested getting together a quantity of zinc containers and carbon rods, and then commencing the filling process. Surrounding the carbon rod was a “depolarizing paste” consisting of a mixture of approximately equal quantities of carbon or plumbago powder and manganese dioxide (pyrolusite) made into a paste with a 1 per cent. solution of gum tragacanth. The electrolyte consisted of about 85 per cent. of plaster of Paris and 15 per cent. of ordinary flour mixed to a just-wet paste with a strong solution of sal ammoniac,

For the student looking for a science fair project, making a battery is always a worthwhile option.  In addition to this set of instructions, we have many other  similar ideas on this site.



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Admiral Model 12-B5, 1940

1940FebRadioRetailingEighty-five years ago, the War was still over a year away for America, but it was raging in Europe. With a shortwave receiver, you could pull in the war news directly from Europe. And thanks to the Admiral model 12-B5, you could do so for the unheard of price of only $12.95. Of course, there’s been a lot of inflation since 1940, and according to this inflation calculator, that works out to $290 in 2025 dollars. But we think it would be worth the investment.

This ad appeared in the February 1940 issue of Radio Retailing.