Alexander Stepanovich Popov. Wikipedia photo.

Today marks the 160th birthday of Alexander Stepanovich Popov, born on March 16, 1859, in Krasnoturinsk, Sverdlovsk Oblast, Russia. He is regarded in Russia and much of Eastern Europe as the inventor of radio. He improved the coherer to the point where it could receive radiotelegraph signals at a reasonable speed.  In 1895, he employed the improved coherer as part of a lightning detector.  On March 24, 1896, he used radio to transmit a message between university buildings in St. Petersburg.

1989 Soviet stamp showing Povov demonstrating first radio, 1895, Wikipedia image.

Yesterday, we carried a quiz from the March 1969 issue of Popular Electronics. Here are the answers and explanations.

Fifty years ago this month, the March 1969 issue of Popular Electronics carried this quiz on Ohm’s law. A few of the questions have some tricky aspect that you might need to notice, but they can all be solved with the familiar E=IR equation.

Answers will appear here tomorrow.

Shown here are students at South Side High School in Rockville Centre, New York. During the club’s two year history, fifteen members had obtained FCC licenses. This included three girls, and the majority of the current class studying code were also girls.

The club station call sign was K2LAK, and was under the direction of the school’s industrial arts director, Miles Stireman, K2KAT. Shown at left at the National NC-300 and Johnson Valiant are members Diane Anhel, KN2LLB, and Ed Davis, K2PHK.

The photos appeared in the March 1959 issue of Electronics Illustrated.

Eighty years ago this month, the March 1939 issue of Radio Retailing magazine carried this ad for an interesting looking mobile shortwave converter.

From ABC Radio Laboratories of 3334 N. New Jersety St., Indianapolis, IN, the Model 600 covered the 49-16 meter bands. It noted that the unit was “especially adapted to use in tropical countries and the more remote parts of the world.” The set retailed for $24.95.

Also shown was a converter that tuned 1500-2600 kHz to pull in police calls “for use of police and other law enforcement officers.”

The unit is a bit reminiscent of the Gonset shortwave converter, which came out in the late 1940’s.  I actually had one of the Gonsets installed in a vehicle in the late 1970’s, and it was a fairly sensitive receiver until one day when the magic smoke leaked out.  Since the solid-state car radio wasn’t capable of supplying B+, I used a separate vibrator power supply.

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.

With 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.”