Author Archives: clem.law@usa.net

1928 Soviet Crystal Set & Galvanometer Experiments

This illustration of a handsome crystal set listening post comes from 90 years ago, in 1928 issue number 1 of Радиолюбитель (Radio Amateur) magazine, illustrating an article by A. Pushkov.

Elsewhere in the magazine, it’s apparent that, just like their Western counterparts, young Soviet experimenters discovered the fun that could be had with a milliammeter, although I have to admit that I never thought to conduct the second and fourth experiments shown here:

(The piece of metal in the above diagram is marked “железо”, iron.)

The sensitive galvanometer was probably a valuable instrument in the 1928 Soviet Union. Modern students desiring to reproduce these experiments can do so very inexpensively with a digital voltmeter such as the ones shown here:

1944 Toy Phonographs

I was a little bit surprised to see these phonographs for sale in a wartime catalog, but they are shown here in the 1944 Sears Christmas catalog.

They’re surprising for a couple of reasons. First, they’re an interesting juxtaposition of an acoustic phonograph with an electric motor. I assumed that acoustic phonographs were wind-up models, and that electronic phonographs had an electric motor. But there’s no reason why there can’t be some overlap..

But I was more surprised to see phonographs for sale, despite the fact that the manufacture of phonographs had ended by order of the War Production Board (WPB) on April 22, 1942. It’s unlikely that there was much old stock left in the Sears warehouse at that point (although it’s not at all unlikely that there were electric phonograph motors left over when the ban went into effect).

Interestingly, these are not being sold as phonographs. They are being sold as toy phonographs. I’m not aware that the WPB made an exception for acoustic phonographs. But apparently, they did make an exception for toy phonographs.

The model on the right looks like a toy, especially with the decorations. But the model on the left doesn’t really look like a toy. It looks more like just a low-end portable phonograph. I suspect that more than a few were sold, not for the kids, but because it was the only new phonograph people were able to buy.

The video below shows a similar instrument manufactured, surprisingly, as late as 1974:

International Grid Chase Update

As I previously posted, during 2018, the ARRL is conducting an Amateur Radio event known as the International Grid Chase. The event is a friendly competition to see who can work the most grid squares on any band or mode.

A grid square is a division of the earth into sectors one degree latitude by two degrees longitude. Each one is designated by a four character identifier. For example, I live in EN34

After I wrote my previous post, the official rules for the event were announced. And contrary to my initial interpretation, it is important to work grids on as many bands and modes as possible, since points are awarded for each grid on a new band or mode.

With my modest station, I’m certainly not in the big leagues. But with a very modest effort, I now have 100 grids confirmed, as shown on the map above. And because I have some of them confirmed on more than one band or mode, I have a total of 162 points, placing me in about 1953rd place out of 17287. That places me in about the top 11%, which I consider to be respectable given a modest station and limited time.

Interestingly, on a later update of the Leader Board shortly after writing this, I see that I am now tied with W1AW for 1928th place. Strangely enough, this is the second time I’ve been tied with the ARRL’s Headquarters station:

Points are awarded as the contact is confirmed on Logbook of the World (LOTW). Since confirmations continue to filter in, this score will continue to rise.

Most of my contacts so far came from two contests, the CW and SSB weekends of the North American QSO Party. A majority of contesters seem to participate in LOTW. Therefore, by making as many contacts as possible, the score continues to rise. As you can see from the map above, most of my contacts are from the United States, with a smattering of contacts from Canada, Mexico, and the Caribbean. The handful of European contacts I’ve made so far have not yet confirmed on LOTW.

So far, I have no digital contacts. So at the very least, I’ll need to get set up for PSK31, which requires only very minimal hardware between the computer and radio. Every contact I make will be worth one point, since I have yet to work any grids in a digital mode.

Two upcoming contests are worthy of note. Next weekend is the Minnesota QSO Party, which has participation in all or most Minnesota counties. It will be a good opportunity to get the 26 grids which lie completely or partially in Minnesota. Other state QSO parties later in the year will provide similar opportunities.

And the ARRL DX Contest (CW in February and SSB in March) will provide a lot of new grids, since almost everything outside the U.S. will be new for me.

To follow your own progress, a good tool is the N1KDO Grid Mapper, which was used to generate the map at the top of the page. When I started as a Novice, one common activity for new novices was to color in a “Worked All States Map,” which was nothing more than an outline map of the United States. The process of coloring in a map can be addictive, and I often find myself refreshing the map to see if other confirmations have come in, with another square turned red.

The DX Hounds Are Back, 1948

Seventy years ago this month, the January 1948 issue of Boys’ Life magazine let its readers know that after a wartime absence, amateur radio was back, and that the DX Hounds were back. The article began with the story of how an Ohio ham, former Navy radio operator Paul L. Hughes, saved 300 in New Mexico. One night, Hughes heard a call on 10 meters from a motorist stranded in a snowstorm with 300 other motorists in New Mexico. Hughes found a ham in Albuquerque who phoned the New Mexico State Police, who had a rescue party on the way 26 minutes after the call for help.

For scouts interested in getting started, the article recommended three books, How to Become a Radio Amateur and the License Manual from the ARRL, as well as, of course, the Radio Merit Badge pamphlet. Each was available for 25 cents from the respective publisher.

1948 Permeability Tuned Receiver

Even though the war was over, it appears that aluminum was still in somewhat short supply, or at least expensive, in 1948, since it’s not unusual to see radios from that era using permeability tuning, which means that a variable capacitor was not required.

Here’s one such example from the January 1948 issue of Popular Science. This little one-tube set uses a 12BA6 as a regenerative detector, with a 35W4 rectifier and “curtain burner” cord to run the filaments. Tuning is accomplished by moving a slug through the coil, changing the inductance. The complete coil assembly was available as a commercial part, and was listed on the parts list as merely a “permeability tuning unit for regenerative circuit.”

The accompanying article didn’t include an explanation for hooking up the dial string, since the entire assembly was commercially available, and the other parts were simply squeezed in.

Interesting Math Relationships

Today, we offer some fun math facts to amaze your friends.

You don’t need to be able to read the text to see these interesting mathematical relationships. This table appeared in the January 1958 issue of Юный техник (Young Technician).

Eunice Johnson, KOA Denver

Shown here on the cover of the January 1928 issue of Radio Digest is Eunice Johnson of KOA Denver, described as “the most beautiful artist” in radio. According to the magazine, she was “still in her teens, but she sings and talks to her audience like an old timer.”

The GE station signed on in 1924 with 5000 watts, increasing to 12,500 watts in 1927. It went to its current power of 50,000 watts in 1934.

1938 Two-Tube Regenerative Receiver

Eighty years ago, the January 1938 issue of Shortwave and Television magazine carried the plans for this two-tube regenerative shortwave receiver. With plug-in coils, the set would cover 550 through 9 meters. The set used two 1.5 volt tubes: The RK42 triode served as regenerative detector, and a dual RK43 provided two stages of audio amplification.

The set was capable of pulling in stations from around the world, and “there is practically no limit to which this receiver will cover. So long as general receiving conditions are favorable, this little set will work wonders.”

The use of two variable capacitors allowed for bandspread tuning, and a variable resistor was used for regeneration.

1943 Coil Winding Tip

75 years ago this month, the January 1943 issue of Radio Craft carried this hint for winding coils.

The idea was sent in by one Tony Calabrese of White Plains, NY, and was billed as a good method for anyone to get a professional looking coil.

One end of a designated length of wire was attached to the wall or some other fixed object, with the other end attached to the coil form. After a couple of turns, the weight was placed on the wire to maintain tension.

When the coil was complete, the weight was slipped off, resulting in a neat coil with evenly spaced turns.

Recent Media Mentions

While it didn’t mention OneTubeRadio.com by name, we were quoted in August by WJLA-TV in Washington, D.C. In the excitement leading up the eclipse, I missed the article, but it covered many of the points addressed in our Take Your Kids To See the Eclipse post.

We were also privileged to be linked to by IEEE Spectrum for our description of the Luxembourg Effect.

Finally, this blogger recently wrote about our Elimination of Bias Continuing Legal Education programs.