One hundred years ago today, 13-year-old Grace Weaver of Oakwood Village, Ohio, near Dayton, made the front pages by putting together her own five-tube neutrodyne radio. On her first night, she pulled in Los Angeles.

She is shown here on the front page of the Radio section of the Indianapolis Times, January 29, 1925.

Sixty years ago, the January 1965 issue of 73 Magazine showed how to make this simple Grid Dip Oscillator (GDO or “Grid Dipper”.)

The GDO is handy for quickly measuring the resonant frequency of a tuned circuit or of an antenna. The GDO’s coil is exposed, and it’s poked into the coil of the circuit in question. For an antenna, a small loop of wire attached to the antenna goes around the coil. The frequency is adjusted, and at the resonant frequency, the meter showing the grid current drops precipitously. If you need the exact frequency, you can find the signal of the GDO on a receiver, or use a frequency counter.

This example uses a 3S4 tube, and has the convenience of being able to run from batteries. Of course, these days, the same thing can be done with transistors. Even though transistors have no grid, many old timers still refer to the instrument as a Grid Dipper. Hams these days are more likely to use an antenna analyzer, but the Grid Dipper gets the job done in an elegant analog fashion.

For many radio hobbyists, this could very well have been the first transistor radio they had ever seen. The invention of the transistor was announced in 1948, and the first commercial example to hit the market was the Raytheon CK-703 later that year. The January 1950 issue of Radio News showed how to build this project, a crystal receiver, with three stages of audio amplification, courtesy of the new “crystal triodes.”

The new transistors resembled miniature tubes, and required sockets. The collectors and emitter terminals had pins, and the base connection was to the brass case of the device. Sockets had not yet hit the market, so the builder, Rufus Turner, K6AI (earlier W3LF), had to fabricate them himself.

He noted that the set would not drive a loudspeaker, but would “give a walloping good signal in high-impedance headphones.” He noted that “enterprising radio men undoubtedly will find a host of applications for this device.”

Turner is said to be the first African-American licensed amateur radio operator. He had no formal education in electronics, but managed to achieve Professional Engineer status in two states. He was involved in the development of the 1N34 diode with Sylvania. When he did go to college in the late 1950s, he received his degrees in English and became a professor of English at California State College, although he continued to publish in electronics.

One hundred years ago this month, this couple were enjoying some dance music courtesty of their Paragon receiver. In this ad in the January 1925 issue of Radio Retailing, the manufacturer, Adams Morgan Co., 14 Alvin Ave., Upper Montclair, NJ, reminded retailers that if they were not featuring Paragon, they were missing out on profit opportunities.

Shown here, at the reins, is 73 Magazine publisher Wayne Green, operating some six-meter mobile. Seated next to him, in the raccoon coat, is Bob Cushman of Cushcraft, the maker of the Squalo antenna. Pulling the duo is Arabian stallion Alrun, said to be the pride of 73 farms.

The photo, taken by K2YDD, appeared on the cover of 73 Magazine, January 1965.

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