Monthly Archives: March 2019

1944: Sky Radio Blankets Enemy

1944MarRadioCraftSeventy-five years ago this month, the March 1944 issue of Radio Craft magazine presented this idea of how invading forces could blanket the enemy with radio by sky. The idea was to alert civilians as to the invasion and give instructions. The expendable 500 watt transmitters shown here would be dropped over the teritory in question and would broadcast a prerecorded message from magnetic tape or wire. Another possibility would be to drop PA systems, which would begin playing at 3000-4000 feet.

The advantage of this system was said to be that the aircraft could leave the area immediately. In more recent times, the U.S. military has, indeed used airborne transmitters, but stationed in the aircraft.



Science Fair Idea: Plants Give Off Oxygen

1939MarPSMany of our science fair ideas are geared toward the student prone to procrastination. If you look through our site, you’ll find many projects that look spectacular but can be whipped up in a single evening. This one doesn’t come under that category, since it requires several days of being set aside. But still, it establishes some meaningful science and has the added advantage of including something bursting into flame.

To show that plants put out oxygen, the experiment collects some of the gas emitted by a plant. After enough has been collected, the student can establish that it’s pure oxygen by placing a small smoldering piece of wood or paper into it, where it will burst into flame.

This idea appeared in Popular Science 80 years ago this month, March 1939.



1939 “Little Giant” Radio-Phono

1939MarPM1

Each year, the March issue of Popular Mechanics carried the plans for a receiver dubbed the “Little Giant.” The rendition 80 years ago in the March 1939 issue was this four-tube TRF receiver complete with built-in phonograph. While the set was not especially designed for beginners, the magazine noted that the set was not difficult to build. It was billed as a portable, but the magazine noted that it could be adapted into an old console or large table cabinet.

1939MarPM2With a 20 foot antenna, the set would get the local stations with surprising volume. And with a 50 foot antenna, the set would pull in more distant stations. It weighed in at 16 pounds, and could provide entertainment for vacationers, as shown above, or could provide entertainment and dance music as shown at the left. “Phonograph records may be played and amplified when broadcasting stations leave the air.”

1939MarPMschematic



How To Change Your Picture Tube: 1959

1959MarEESixty years ago, the March 1959 issue of Electronics Illustrated showed how to change your own picture tube, including diagrams for common configurations of both horizontal and vertical chases. The article explained how to short out the capacitors in the power supply, lest the handyman get zapped by high voltage from a set that wasn’t even plugged in. And it also explained how to avoid shards of glass flying everywhere if the tube imploded.

But it was the magazine’s cover that offered the reminder that to do this sort of job, you really ought to put on a sport coat. And while it’s not visible in the photo, it seems likely that this home repair man is wearing a tie.



Charles D. Tandy, 1918-78

1979MarEEForty years ago this month, the March-April 1979 issue of Elementary Electronics carried this tribute to Tandy Corporation founder Charles D. Tandy, who had died of a heart attack at the age of 60 in November 1978. Tandy was best known in the electronics world as having purchased the fledgling Boston Radio Shack chain in 1963. The author of the magazine was none other than Lewis Kornfeld, the president of Radio Shack both before and after Tandy’s purchase.

According to Kornfeld, nothing made Tandy angrier than empty hooks in the parts department. He questioned why there could be even a single out-of-stock item when “I’ve made your life simple by eliminating thousands of slow movers.”

Tandy got his start in the leather business, and while serving in the Navy during World War 2, he noticed sailors being taught knitting and needlepoint as part of their recuperation. He believed the men would prefer leatherwork, and established a system of craft work for the hospitalized men.

The author of the tribute took over Tandy’s role in the company. The company’s monthly flyers included a “Flyer Side Chat,” in which Kornfeld would offer his opinions on some subject of interest. Interestingly enough, most (or perhaps all) of the Flyer Side Chats have been collected into a single volume. In addition, students of marketing would be well advised to read Kornfeld’s classic, “To Catch a Mouse, Make a Noise Like a Cheese.”