Steadily increasing use of CW paralleled exploration of ever shorter wavelengths, and the two pursuits complemented each other. Amateurs were setting new records at a whirlwind pace. CW use in traffic handling had grown tremendously in the past year, and in June 1922 ARRL message traffic on CW exceeded that on spark for the first time.1 By the following February CW traffic accounted for nearly 90% of the total.2 Hams across the country found CW especially effective in summer when … Continue reading

Spark to CW

Through the years, starting well before the war, amateurs occasionally had discussed undamped oscillations and how Audions could be used to detect them.1 By summer 1916 a government radio inspector was predicting that in five years most amateurs would be using undamped waves.2 QST noted that with the influx of “mature men” and a willingness to spend more (around $250) on equipment, it was just a matter of time before a “Mr. Undamped Wave” would appear and lead the way. … Continue reading

Waking Up

As amateur stations fell silent, the airwaves continued to carry commercial and military signals, many from the fingertips of former radio amateurs. But despite their contributions there were some in government who still sought to limit or eliminate the use of wireless by private individuals. As the battles ceased in Europe, amateur radio came under renewed attack at home. Bills introduced in both houses of Congress shortly after the armistice sought to turn control of all use of radio over … Continue reading

The Audion

Vacuum tubes revolutionized radio, changing it more than any other single invention. When first introduced, however, even the scientists and engineers working with them did not fully understand how they worked. One of the first tubes to appear in QST was the Audion, by DeForest. Although it had been introduced back in 1905, it was expensive and amateurs did not begin to use it until seven years later, when 22-year-old Edwin Armstrong demonstrated its practical use as a regenerative detector. … Continue reading

Spark Radio

Before tubes became available and affordable and made electronic oscillators practical, the spark gap circuit was the most widely used method for generating radio frequency (RF) signals. Its basic design and operation are simple. A capacitor is connected in series with an inductor and a pair of electrodes separated by a small distance—a spark gap. The capacitor, commonly called a condenser at the time, is charged by a high voltage supply. When this voltage reaches a critical level, a spark … Continue reading