A hundred years ago, a radio would have made the perfect wedding present, and this June bride put out the word that she wanted one. Word spread, and it turned out that everyone got her a radio. Here, she’s reacting with surprise. But she’ll soon learn that you can never have too many radios, and she will have one in every room.
The artwork appeared on the cover of Radio News, June 1925. The artist is Howard V. Brown, whom we’ve seen previously.
Eighty years ago this month, this circuit for a one-tube broadcast radio appeared in the June 1945 issue of Radio Craft. It was sent in to the magazine by a soldier stationed in Florida, who assembled it in his barracks with various parts gathered around camp.
He reported that with a 45 volt battery, the set provided good loudspeaker volume. A 1D8GT tube served as both amplifier and detector, and all stations came in loud and clear.
Unfortunately, we don’t know the identity of the soldier, due to a typographical error by the magazine. He was stationed at Camp Gordon Johnston, Florida. Unfortunately, the author’s name was listed as “Camp Gordon” with a town of Johnston, Florida.
The first automatic amateur radio repeater station was put on the air in 1956 by Art Gentry, W6MEP, and it’s been on the air ever since. But you can see that the idea had been around for a while, as shown in this article 80 years ago, in the June 1945 issue of QST.
At the time, Amateur Radio was still off the air for the duration of the war, but some hams involved in civilian defense activities did have authorization to operate as part of the War Emergency Radio Service (WERS), usually on the 2-1/2 meter band. One such WERS station was WKKW in Hanipshire County, Mass. The network was headed up by a net control station (NCS) at one of the highest points in the county, which ensured good coverage. The problem was, however, that not all stations could hear each other. So if a message needed to be relayed, it meant an added step of the NCS relaying it.
The solution was an automatic relaying system at the NCS station. While the article called it “automatic,” it did not automatically hit the air as with a more modern repeater. Instead, the NCS merely patched the audio from a second receiver into the transmitter, with the patch cord shown here. He monitored through headphones, and switched back when the message was over. Of course, the transmitter and receiver had to be on different frequencies, so when a message had to be retransmitted, the originating station was told to QSY to 112.7 MHz, and the repeated signal was on the net frequency of 114.6 MHz.
The equipment had to be reasonably well shielded, and the antennas had to be separated. (The article noted that the feed line was a twisted pair.) The article concluded by noting, “it is to be hoped that others will experiment with this and other simple means of relaying, since it is an interesting field of experimentation and one which offers a good return in the way of improved WERS operation. It suggests, also, interesting possibilities for postwar amateur activities at the high frequencies.”
Seventy years ago this month, this couple are enjoying some quality time together with their radio control boat, as shown on the cover of Radio News, May 1955. The secret of a successful cruise was a reliable receiver, such as the one described in the magazine.
The author’s three-tube set reported very reliable service on 27.255 MHz. With a three-watt transmitter, it had a safe range of a mile. The three-tube supreregenerative circuit used an RK61 gas tube detector. While this type of tube sometimes experienced a short life, this was ameliorated by very low current.
Eighty years ago this month, the May 1945 issue of Radio News showed this transmitter-receiver mounted in an “innocent-looking traveler’s suitcase,” and seized from a German spy by agents of the FCC Radio Intelligence Division. It was said to be substantially built and of an up-to-date circuit design. It included a tool set, vibrator power supply, and wire for erecting antennas.
You can see what appears to be the same model at the Imperial War Museum.
Eighty-five years ago, this father-daughter team is hooking up a temporary indoor antenna. But to avoid marring walls or woodwork, they’re following a hint shown in the May 1940 issue of Popular Mechanics. They are using several small rubber suction cups, which can be easily removed when not required.
Eighty-five years ago this month, the May 1940 issue of Popular Science showed how to put together this four-tube (1A7GT, 1N5GT, 1H5GT, 1C5GT) portable receiver. As shown in these illustrations, it was guaranteed to enhance any activity at home or on vacation. Powered by a 1.5 volt A battery and 90 volt B battery, the superheterodyne design could pull in stations 100 miles away during the day, or 500 miles at night, with only the built-in loop antenna. For greater DX, an outside antenna could be connected.
The magazine provided proof, in the photo at left, that the set weighed in at a mere eleven pounds.
Here’s something I’ve never seen before. Radio News carried lists of new TV stations to come on the air, and periodically had complete lists. This one is from the May 1955 issue.
Among the data presented is the wavelength (of the video carrier), but it’s given in feet, and not meters! The only reason I can think of for this is for antenna construction. If you needed to build an antenna of a half wavelength, then you would probably be measuring in feet, and I guess it would save a little bit of time to have the conversion done for you.
But almost anyone building an antenna would know that if you started with frequency, then the formula for the length of a dipole was 468/f. And that formula took into account end effects, and was really 95% of the true wavelength. Has anyone else ever seen radio wavelength expressed in feet?
The plans for this handsome one-tube receiver appeared a hundred years ago this month in the May 1925 issue of Popular Science. The set was said to be ideal for the beginner, but still boasted long-distance reception. Regeneration was controlled by a variable capacitor, and this was said to reduce squealing, by virtue of the fact that only RF, and not audio, was fed back. The set called for an antenna of 75-100 feet. In testing, the set pulled in Chicago from a less than ideal location in New York.
Back in the day, kids were warned about things like not listening to the radio in the bathtub, or the importance of wearing shoes in the basement. This was because caution was warranted around many electrical devices, especially the “AC-DC” radio, which was the most common design.
These circuits were such that one side of the electrical cord was often connected directly to the chassis. For some semblance of safety, there were some precautions taken. First of all, the cabinet was often made of wood or plastic, which insulated the chassis inside. Even then, though, there was often a screw visible in the back. In some cases, the connection to the chassis was through a capacitor, although that could eventually become leaky. So taking your five-tube radio into the bathroom probably wasn’t a good idea.
This hint for adding a bit more safety appeared in Radio-Electronics 75 years ago, May 1950. If the plug is plugged in with the correct polarity, then the risk of shock is minimized considerably. These days, if you’re restoring an old radio, it’s a good idea to add a polarized cord and/or a three-prong plug. Even so, it’s probably best not to use it in the bathroom or near the kitchen sink.