In 1924, the Trego Radio Mfg. Co., 1427 Chestnut St., Kansas City, MO, offered this one-tube set, the “Baby Grand” in their catalog. For $28.75, you got everything you needed, including the tube, batteries, and even antenna and ground wire. The batteries even came installed inside the set, which was said to have a range of 500 to 1000 miles.
The set was also available without tube, batteries, or other accessories, for $15.35.
Sixty years ago this month, the January 1959 issue of Popular Electronics showed how to put together this portable one tube FM receiver. The set used a single 1AG4 tube as a superregenerative detector, and used a penlite cell for the filament and two 22.5 volt batteries to supply the B+.
Even though a superregenerative receiver is best suited for AM signals, it does an excellent job on FM with slope detection. The tendency of the set to radiate was put to advantage in the instructions for calibrating the dial. The article suggested using a second receiver, tuning it to 88, and then tuning the portable until the rushing sound was heard on the other receiver.
The young man shown here (quite possibly the son of article author T.A. Blanchard) is probably getting ready to collect his first Social Security check. But sixty years ago, he was shown in the 1959 issue of Radio-TV Experimenter operating this simple crystal set.
The antenna and ground leads are soldered to “frictioned” paper clips, which could be connected to a convenient antenna such as the dial stop on a telephone. Tuning was accomplished with the adjustable ferrite antenna coil. The set would not tune the entire broadcast band, but the article included values for the fixed capacitor to cover various portions.
While not nearly as spectacular as a solar eclipse, another interesting astronomical phenomenon will be visible this Sunday evening throughout the Western Hemisphere. This will be a lunar eclipse, in which the moon passes through the shadow of the earth.
The eclipse begins at 9:36 PM Eastern Time (8:36 CST, 7:36 MST, 6:36 PST) with the penumbral phase, as the moon enters the outer shadow of the earth. The brightness of the moon will decrease, but the small change in brightness probably won’t be visible to the naked eye.
About an hour later at 10:33 PM Eastern Time (9:33 CST, 8:33 MST, 7:33 PST), the eclipse enters the partial stage. At this time, the earth’s shadow begins to eat away at the moon. This continues until 11:41 PM Eastern Time (10:41 CST, 9:41 MST, 8:41 PST), when the eclipse becomes full, and the moon is completely within the shadow of the earth.
Unlike a solar eclipse, the times are more or less identical wherever you are. You only need to adjust for your time zone.
Even though the eclipse is full, the moon does not become fully dark. This is because the moon is illuminated by a ring surrounding the earth, namely, all of the sunrises and sunsets taking place on earth.
At 12:43 AM Eastern Time, the eclipse once again becomes partial. At 1:50 AM Eastern Time, it re-enters the penumbral phase. At 2:48 AM Eastern Time, the eclipse ends.
We previously wrote of an interesting story of a lunar eclipse of July 15, 1916. This eclipse affected the Shackleton Antarctic expedition. The team led by Aeneas Mackintosh was waiting for a full moon to embark, but were surprised to see the moon entering an eclipse as it rose. Fortunately, the eclipse was only partial and enough light remained to make the voyage.
For a snapshot of wartime consumer prices, this Walgreen’s ad appeared in the Milwaukee Journal 75 years ago today, January 20, 1944.
This handsome home entertainment installation appeared on the cover of Radio Television News 70 years ago this month, January 1949. While it appears to be a single console, it’s actually a custom installation of discrete components, a television, radio, and record player.
The issue provided guidance for dealers looking to move into this field, and suggested that thoughtful design and installation of such custom designs could be a lucrative proposition.
Wartime parts shortages were undoubtedly the inspiration for these two crystal sets from the January 1944 issue of Popular Mechanics. While commercial parts could be used, from the junk box, salvaged from an old radio, or from a mail-order house, the article showed how to make most of the parts. The article notes that the newcomer needed only a good set of headphones to build either set from scratch.
The first set, shown above, omitted a variable capacitor, as it used a variometer for tuning. It did require one fixed capacitor, but the article shows how to make one using copper foil and either mica or wax paper.
A commercial fixed crystal can be used, but the article also shows how to make one. The crystal is mounted inside an old tube base and sealed with wax. The use of an old 4-prong tube socket meant that a commercial fixed crystal could be substituted at a later time.
The second set, shown above, featured a variable capacitor for tuning, which was constructed “book” style. The top plate, made of spring brass, was hinged and moved up and down from the lower plate.
The sets were said to have a range of about 25 miles.
110 years ago this month, parents dealing with perverse or obstinate children might have received some inspiration from this item appearing in the January 1909 issue of Popular Electricity. While details such a voltage are omitted, noted child expert Dr. Elbert Landone suggests zapping the children with a mild electrical shock to bring them in line.
Eighty years ago this month, the January 1939 issue of Radio Retailing devoted most of its pages to the use of radio in education. Of course, the focus was on how the dealer could tap this market. The most basic use of radio, of course, is shown above. A set is brought into the classroom for these Midwestern students to listen to a program of educational value.
Wiring the school with a public address system would be, of course, a lucrative sale. In addition to being able to make announcements immediately, the magazine suggested educational uses for the equipment. Below, for example, students who handed in the best writing are allowed to broadcast their work over the PA.
We frequently publish details of slightly dangerous but interesting demonstrations, along with an admonition to be careful. We encourage kids to carefully have fun with high voltages, dangerous chemicals, etc., and we are confident that they will act responsibly and safely. But in this case, we take the unusual step of saying, in no uncertain terms: Don’t do this.
A lot of things could go wrong. There could be a kink in the tube, or the end could get blocked while your hapless assistant is down there for “several hours.” And there is no description of how the assistant is supposed to get the hose out of the dirt and remove the cork, since it was cleverly concealed behind a little bit of dirt.
In addition, even if the poor guy can breathe, he’ll probably be crushed by the dirt you’re tossing on him. In other words, the poor guy will die. Don’t do it.
The illustration appeared ninety years ago this month in Science & Invention, January 1929.
