One hundred years ago, an entrepreneurial radio dealer in Horsham, England, noticed that interest in wireless was lagging in nearby villages. He took it upon himself, therefore, to equip a motor van with a complete receiving set an hit the road. He paid periodical visits to enable the inhabitants to enjoy a wireless concert, and to bring to their attention the fact that his firm could sell them a set of their own.

In this picture, in the February 1925 issue of Wireless magazine, and it is noted that great pleasure is written upon the faces of the children listening here.

A hundred years ago this month, the cover of the February 1925 issue of Science and Invention gives Hugo Gernsback‘s vision of what telemedicine would look like. Of course, the word “telemedicine” hadn’t been coined yet, but the concept is there: “The doctor of the future, by means of this instrument, will be able to feel his patient, as it were, at a distance. The doctor manipulates his controls, which are then manipulated at the patient s room in exactly the same manner. The doctor sees what is going on in the patient’s room by meads of a television screen.”

The device did have a name, the “teledactyl.” That’s not a type of dinosaur, but instead means that it could feel at a distance.

Eighty-five years ago, this radio listener is showing off her RCA receiver. More specifically, she is showing the loop antenna mounted on the back, manufactured by Consolidated Wire and Associated Corporations. She is on the cover of the February 1940 issue of National Radio News, which devotes several pages to the use of such antennas.

If you see some buyer’s remorse in her eyes, it’s possibly because the small antenna doesn’t work as well as the old aerial that was previously connected to the set.  If the serviceman was approached by a customer wanting the added portability of such an antenna, it was recommended that they explain the shortcomings. As opposed to a longer antenna, fewer stations could be pulled in. But if the receiver was fairly sensitive, the strong local stations could be heard. If the receiver covered the shortwaves, the customer would need to be told that reception would be severely limited.

Seventy years ago this month, the February 1955 issue of Popular Mechanics showed how to build this transceiver for the two-meter ham band. The heart of the four-tube set was a 6C4 tube which served as superregenerative detector on receive, and as a Colpitts oscillator on transmit. Since the tuning circuit was in common with both circuits, there was no problem with tracking, but care had to be taken to keep the entire transmitted signal within the band.

When it comes to one tube radios, the holy grail is one that produces loudspeaker volume. And 75 years ago, this humble set from the February 1950 issue of Radio Electronics rose to the challenge. The set used a 3B7 ultraudion with some superregeneration. Regeneration was automatic, and no ticker winding was required on the coil, which was a permeability tuner.

The choice of a volume control was interesting, namely, a wire-wound potentiometer right in line with the antenna. The author noted that the inductance formed part of the circuit, and a carbon resistor shouldn’b be used. The author used a surplus 103.5 volt battery for the B-plus, but noted that two 45 volt batteries in series would be adequate. An outdoor antenna was needed. In areas with strong stations, 25-50 feet would work. But in rural areas, 100 feet as high as possible would be needed.

As an added bonus, the set could be used as a code practice oscillator. The plate of the audio section of the tube was connected through the key to a capacitor to ground.

But it’s not just a program, thanks to the golden tone of her General Electric radio. This ad appeared in Life magazine 85 years ago today, February 19, 1940.