The summer of 1923 was to be a big one for radio, as predicted by the June 1923 issue of Wireless Age. The magazine editorialized that radio would be a major feature of summer camp experiences, and many farm families would be introduced to radio by their city visitors.
The cover featured this illustration by Charles S. Jaeger. But somehow, play-by-play broadcasts of rowing crew competitions never quite caught on.
The June 1948 issue of Radio Craft showed this circuit for a one-tube “reflex” receiver, so named because the tube served double duty. The input was connected to the antenna circuit, and the tube served as an RF amplifier, with the output going to a then relatively new 1N34 diode. The audio then went through a transformer and volume control, where it was fed back to the tube, which then amplified the audio. The audio then passed through an RF choke on its way to the speaker.
The circuit had been sent to the magazine by one Arthur S. Bean of Baltimore. The magazine noted that his design provided good volume and moderate selectivity.
There was a time when people dressed up to listen to the radio, and 85 years ago was one of those times, as demonstrated by this young woman on the cover of the June-July 1938 issue of National Radio News.
You would dress up, too, if the receiver you were listening to was the General Electric model F-96 Electric Touch Button Tuning Radio. The handsome nine tube set retailed for $110 (over $2300 in 2023 dollars). It featured sixteen pushbuttons, and tuned both broadcast and short wave, as well as pulling in police calls.
Many hams from the 1970s and later are familiar with variations on W1CER’s (later W1FB) Tuna Tin II, a transmitter which used a tuna can as its enclosure. But the 1950s had its own variation on the same theme, as shown here in the June 1953 issue of Radio News. A 117L7GT tube wouldn’t fit inside a tuna can, but it did fit into a coffee can, so that’s what was used.
This 80-meter transmitter was actually a club project by the Wantah Radio Club on Long Island, New York. It was designed to spur some activity as the club members built and used them. Once the rigs were built, they used them for local nets, and also used them for contests, such as for the most distant contact, and the highest number of states worked.
Half the tube was used as a Pierce oscillator, with the other half serving as rectifier. We’ve seen other transmitters using the same tube, and it’s a natural for a small one-tube QRP rig. This design put out about 3 watts, and the station on the other end was often surprised by the power used. The article warned that to save money, half of the line cord was attached to the chassis, making it potentially hot. Therefore, those making the set were cautioned to use care in plugging the cord in with the right polarity. They described a test circuit to see if it was plugged in the right way, but that circuit would trip a modern GFCI outlet.
The tuning circuit shown in the schematic below was “already mounted on a convenient subchassis from a BC-746 tuning unit available at surplus,” as if everyone knew what a BC-746 was. That appears to be an external antenna tuner, one portion of which was used here. If you can’t find a BC-746, the article gives alternatives for making your own.
The set was mounted on the coffee can lid, with the can itself then used as the enclosure. This was said to provide shielding to prevent TVI.
The author of the article was Jim Fahnestock, W2RQA. There can’t be that many Fahnestocks in the world, and since he was from New York, where the famed Fahnestock clip originated, we have to guess that he was related to the inventor of the clip and the namesake of the State Park.
Over the next few years, the TV antenna on top of houses would become a familiar sight, But 75 years ago, the concept was new, even for experienced radio technicians, who were just starting to realize that the way they would stay in business was by embracing television.
Therefore, the June-July 1948 issue of National Radio News, the publication sent to alumni of National Radio Institute, carried an extensive treatise on the subject of antennas for FM and TV. One concept that would soon become familiar, but was probably new to most readers, was “ghosts” caused by multipath interference. The cause is shown above, and the result is shown below.
Eighty years ago this month, the June 1943 issue of Radio News showed the transmitter that was to become known as the “Gibson Girl.” The two downed airmen had nothing but hope, and their potential rescuer was beyond the horizon, with no way of knowing they were there.
But that was soon to change, and the men would have with them a hand-cranked transmitter capable of summoning help over long distances, thanks to an automated message sent on 500 kHz. Rescuers would be able to hear it for hundreds of miles, and zero in on their location through radio direction finding.
The antenna was to be made out of Belden wire, and they were justifiably proud of it.
The June 1963 issue of QST carried the plans for this five-transistor transceiver for 6 meters. The author, David Light, K4IQU, reported a QSO of 15 miles between two of the units, in hilly terrain, presumably on two peaks within sight of each other. He also reported being heard 30 miles away (but not a two-way QSO) with a well equipped station with a beam at the other end.
As shown by the emblem on the set, the goal of the unit was for use in local emergencies. But chances are, most of the use involved the secondary purpose, “having plenty of fun on 50 Mc.”
The superregenerative detector, the oscillator, and the RF amp were 2N1745 transistors. Two stages of audio amplification were used for both transmitter and receiver, and used 2N43A transistors. Power was supplied by a 9-volt battery.
For modern hams, the humble Baofeng handheld can be had for about $30, and almost certainly outperforms (on 2 meters and 70 cm) the humble little rig here. So yes, if all you have is a Baofeng, there’s no reason why you can’t work another Baofeng 15 miles away, or a well equipped station 30 miles away. There are much better radios, but if that’s what you got, there’s no reason why you can’t use it for having plenty of fun on 144 Mc.
Eighty years ago, this west coast air raid warden was subject to call at any moment, but he might need to be somewhere in his house other than next to the telephone. His solution was to use something called an “electric sentry” to alert him.
As near as I can tell, an “electric sentry” was a one-way intercom, which used the house wiring to transmit the signal. The transmitter was plugged in near the telephone ringer. He could then carry the receiver to another room in the house, or even a neighbor’s house, with the assurance that he would hear the ringing phone.
Here, he appears to have the sentry receiver nearby while he repairs a radio. His daughter assists him by trying on his warden’s helmet. The transmitter is shown at right.
The item appeared in the May 1953 issue of Popular Mechanics.
The plans for this one-tube loop set appeared 85 years ago this month in the May, 1938, issue of Radio Craft. While the tuning range is not specified, it appears to be for the broadcast band, and the set was said to give the beginner many hours of enjoyment both putting it together and using it.
According to the magazine, the set was able to pull in signals inside a steel framed building, with enough volume to rattle the headphones.
While it was not primarily intended for use as an interference finder, the directional
characteristics of the loop antenna made it well suited for that purpose.
The same issue of the magazine also showed how to make the one-tube all wave receiver shown at the right. It also included instructions for adding an additional AF stage.
Eighty-five years ago, this young woman was preparing to have her voice amplified with this 30-watt amplifier. We don’t know whether she’s a ham modulating her transmitter to almost 100% modulation, or if she is going to address a crowd through the loudspeaker. The circuit shown here, from the May 1938 issue of Radio News, is suitable for either purpose.
The power output was provided by two 6L6 tubes, and the circuit’s main feature was automatic volume limiting, which would provide distortion-free audio, even at maximum power. This was important for modulating, since the FCC required that modulation be limited to 100%. And for PA work, this meant that the output would be not only loud, but also crystal clear.
