With civilian radio (both transmitting and receiving) shut down for the duration of the war, hams a hundred years ago still had a desire to engage in communications. As we’ve seen prevsiously (here, here, here and here), one method of communicating without the use of radio waves is a ground-conduction telegraph. And a hundred years ago […]
We’ve carried plans for other wireless telegraphs and telephones that relied upon ground conductivity, and here’s another one that comes from a hundred years ago this month, in the July 1917 issue of Electrical Experimenter. This one is a bit mysterious for a couple of reasons. First of all, the receiver appears to contain […]
During World War II, Amateur Radio was off the air for the duration. However, unlike the situation in the First World War, hams were allowed to keep their equipment, and there were no restrictions on listening. Hams were eager to communicate, and with radio unavailable, they were eager to explore other possibilities. Starting with the […]
The gentleman shown above is demonstrating a simple wireless telegraph, the plans for which appeared 75 years ago this month in the December 1940 issue of Popular Science. As you can see from the diagram here, the concept was nothing new, and is quite simple. The transmitter sends an AF signal of about 75 volts […]
The Minnesota Wireless Association (MWA), according to its QRZ.com listing, has been in existence since 1914, and that fact is borne out by the photograph above, which appeared a hundred years ago, in the March 1915 issue of Popular Mechanics. The article describes the station installed in the Minneapolis City Hall, a structure which is still […]
A hundred years ago, the wireless had unquestionably established itself as one of the tools of war. On this day in 1914, the Mexican Port of Veracruz was under American occupation after three days of fierce fighting under the command of Admiral Frank Friday Fletcher. The invasion was a response to the arrival of arms bound […]
Shown here in the July 1913 issue of Popular Electricity is Chicago amateur radio operator Harry Hong Sling, a fifteen year old Chinese-American. According to the magazine, he was probably the only wireless amateur to have a station in the Chicago “Loop”. The station shown here was on the fourth floor of the building where he […]
Yesterday, we presented the problem of how to hook up a telephone to talk across a river from Point A to Point B, without running a wire across the river. Loyal readers knew the answer right away, because we presented a similar system for a 1940 wireless telegraph using four ground rods. Each side of the […]
It’s generally accepted in the history of science and technology that radio couldn’t have been invented until James Clerk Maxwell came up with Maxwell’s Equations in 1865. That theoretically underpinning of radio were verified experimentally by Heinrich Hertz in 1887. (Hertz, it turned out, was using electromagnetic waves of about two meters in wavelength, it turns, meaning […]
I always knew that reknowned Amateur Radio operator Don Wallace, W6AM, had a background in Minnesota radio history. For example, I knew that he was involved with the University of Minnesota Amateur Radio Club, and I knew that he was involved with the Minnesota Wireless Association, whose antenna was a prominent feature on Minneapolis City […]