One hundred years ago this month, the July 1921 issue of Science and Invention proposed this idea of an early tracking device to prevent kidnappings. The photograph in the lower right hand corner served as the inspiration, as it showed a baby carriage equipped with a receiver to play lullabies sent by nearby amateur stations.

The magazine editors took the idea a step further and proposed a transmitter and tracking device, so that the kidnapper could quickly be brought to justice.

Eighty years ago, WLS in Chicago wanted to remind its advertisers of its importance to agriculture by running this ad in the July 28, 1941, issue of Broadcasting. The station knew that many farmers had a radio in the barn and listened to the station while they worked, so it asked them to write in and join the Radio in the Barn Club.

2000 farmers in 14 states responded, demonstrating that American farmers had come to depend on radio for its business value.

Eighty years ago today, the July 27, 1941, issue of the Pittsburgh Press showed the Philco radio offerings for the upcoming model year.

On the internet, according to the meme, nobody knows you are a dog.  But the concept is nothing new, as shown by the cover of Radio News for July 1921.  On the radio, nobody knows you’re a monkey.

Eighty years ago this month, the July 1941 issue of Radio Craft carried this ad for the radio operator’s course offered by Port Arthur College, Port Arthur, TX, known today  as Lamar State College-Port Arthur.  The college was the licensee of KPAC, which the ad notes was the only commercial station licensed by a college.  As such, the modern facility had advertising representative in major cities, and was a full-fledged member of NAB and BMI.  As such, it promised many contacts with industry, and it reported that it received more requests for graduates than it could possibly satisfy.

KPAC was a successful commercial operation, with a top 40 format in the 1950s, moving to a middle of the road format in the 60s.  It was sold to Clear Channel in 1981, and the company attempted to use it to enter the Houston market by upgrading the FM signal.  The station was sold, and it currently operates as KDEI, a Spanish-language Catholic station.

60 years ago this month, the July 1961 issue of Popular Electronics showed this self-explanatory idea for an FM antenna.  The set’s two-wire power cord is replaced with one with three conductors.  The third conductor is inductively coupled to the power line, and feeds the set’s RF stage through a capacitor.

Seventy-five years ago today, the July 22, 1946, issue of Life magazine carried this ad showing the postwar radio lineup from Bendix, manufactured by the radio division of Bendix Aviation Corporation.

One of the sets, the model 646A, was dubbed an “invisible radio,” whose “phantom dial” would disappear when turned off, turning it into a beautiful end table. You can see a nicely restored specimen at this link.

The dial is covered by wood grain, and without the dial illuminated, it does indeed blend in to the rest of the furniture. The speaker grill is at the rear, helping with the illusion. The set originally sold for $84.95.

These cartoons appeared 50 years ago this month in the July 1971 issue of Electronics Illustrated.

Seventy-five years ago today, here is what you would have heard on the radio in the nation’s capital. These listing are from the Washington Evening Star, Saturday, July 20, 1946.

Click on the image to view it full size.