Monthly Archives: January 2019

1944 Crystal Sets With Homemade Parts

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Wartime parts shortages were undoubtedly the inspiration for these two crystal sets from the January 1944 issue of Popular Mechanics. While commercial parts could be used, from the junk box, salvaged from an old radio, or from a mail-order house, the article showed how to make most of the parts. The article notes that the newcomer needed only a good set of headphones to build either set from scratch.

1944JanPMcapacitorThe first set, shown above, omitted a variable capacitor, as it used a variometer for tuning. It did require one fixed capacitor, but the article shows how to make one using copper foil and either mica or wax paper.

A commercial fixed crystal can be used, but the article also shows how to make one. The crystal is mounted inside an old tube base and sealed with wax. The use of an old 4-prong tube socket meant that a commercial fixed crystal could be substituted at a later time.

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The second set, shown above, featured a variable capacitor for tuning, which was constructed “book” style. The top plate, made of spring brass, was hinged and moved up and down from the lower plate.

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The sets were said to have a range of about 25 miles.

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“Electric Shocks for Perverse Children” 1909

1909JanPopElec110 years ago this month, parents dealing with perverse or obstinate children might have received some inspiration from this item appearing in the January 1909 issue of Popular Electricity. While details such a voltage are omitted, noted child expert Dr. Elbert Landone suggests zapping the children with a mild electrical shock to bring them in line.



Radio in Education: 1939

1939JanRadioRetailingEighty years ago this month, the January 1939 issue of Radio Retailing devoted most of its pages to the use of radio in education. Of course, the focus was on how the dealer could tap this market. The most basic use of radio, of course, is shown above. A set is brought into the classroom for these Midwestern students to listen to a program of educational value.

Wiring the school with a public address system would be, of course, a lucrative sale. In addition to being able to make announcements immediately, the magazine suggested educational uses for the equipment. Below, for example, students who handed in the best writing are allowed to broadcast their work over the PA.

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What Could Possibly Go Wrong?

1929JanSciAdvWe frequently publish details of slightly dangerous but interesting demonstrations, along with an admonition to be careful. We encourage kids to carefully have fun with high voltages, dangerous chemicals, etc., and we are confident that they will act responsibly and safely.  But in this case, we take the unusual step of saying, in no uncertain terms:  Don’t do this.

A lot of things could go wrong.  There could be a kink in the tube, or the end could get blocked while your hapless assistant is down there for “several hours.”  And there is no description of how the assistant is supposed to get the hose out of the dirt and remove the cork, since it was cleverly concealed behind a little bit of dirt.

In addition, even if the poor guy can breathe, he’ll probably be crushed by the dirt you’re tossing on him.  In other words, the poor guy will die.  Don’t do it.

The illustration appeared ninety years ago this month in Science & Invention, January 1929.



1959 Hamming Is Fun

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Sixty years ago this month, amateur radio made the cover of Boys’ Life magazine’s January 1959 issue, which featured an article entitled “Hamming is Fun” by long time ARRL staffer Perry Williams, W1UED.

The article featured the radio adventures of a number of young hams, including Jules Madey, K2KGJ, of Clark, NJ, who apparently inspired the cover. Madey, a high school student, put in as many as 49 hours a week running phone patches for men at the McMurdo base in Antarctica. Since the best conditions were in the middle of the night, Madey made a habit of going to bed right after supper and setting the alarm for 10:30 PM.

1959JanBL2The magazine contains two more radio features.  First of all, the Tracy Twins comic shows the boys receiving a radio control airplane that Grandpa insists on operating without a license.  Of course, he gets busted as an FCC helicopter and car swoop in.  Fortunately, he gets off with a warning.

Finally, the Boys’ Life Radio Club had three offerings.  For just 20 cents, they would send out the Radio reprint book containing reprints of earlier articles, along with a free log book.  One dollar would get 60 QSL cards.  And for no cost, the club would send any licensed ham operator scout or scouter a card identifying the bearer as an emergency service ham.

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Fun With Morse: 1949

1949JanBLSeventy years ago this month, the January 1949 issue of Boys’ Life carried this article by William “Green Bar Bill” Hillcourt on the subject of Morse Code.

He points out that in addition to being a requirement for First Class, the skill was part of a Scout’s wilderness adventure. Through the use of Morse, Scouts have been called into action in hurricane, earthquake, and flood.

The article focuses solely on the use of wig-wag flags for sending messages. For relatively short distances, a team consisting of signaler and scribe was ideal. For longer distances, an additional reader was called for, since he would be watching through field glasses.



1959 Auto Dialer

1959JanEESixty years ago this month, the January 1959 issue of Electronics Illustrated showed how to put together this convenient autodialer for a telephone. It was designed to be used with a burglar alarm or fire alarm, to place a call to a pre-designated number.

1959JanEE2The heart of the unit was the lever which went over the phone. In case of alarm, a solenoid released to let the phone off the hook. Then, the same lever was used to dial the phone by pushing the hook buttons. This was driven by the wheel shown here, which rotated thanks to a phonograph motor.

A bell or buzzer would sound over the phone, alerting the owner to the alarm.  The article did note that if the line was busy, the message would not go through.



1944 Locator Soldier

1944JanRadioNewsSeventy-five years ago this month, the January 1941 issue of Radio News showed this soldier, somewhere on the East Coast of the United States. The helmet and stethoscope-like attachment allowed him to listen for and trace the origin of sounds, such as approaching aircraft. The specially trained locator soldiers were required to have binaural hearing, meaning that they had the ability to trace the origin of sounds.



1939 Winking Radio

1939JanPSThe plans for this slightly creepy looking radio appeared in Popular Science 80 years ago this month, January 1939. Billed as an “ideal playroom radio,” the set contained two magic eye tubes that winked when the regenerative tuner was tuned to a station. The mouth served as tuning dial, with the nose taking care of volume.  The set used headphones “so it cannot disturb the rest of the household.”

The 6N5 magic eye tubes were used in the circuit, one as regenerative detector and one as audio amplifier. A type 37 tube was used as a rectifier.

As long as C6 didn’t short out, the set could provide hours of safe fun for the youngsters in the playroom.

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