Page 40 - The Art and Science of Analog Circuit Design

Barry Harvey

Figure 3-4.
Here's the chassis of a first-rate radio. The base metal is chrome-plated for longevity. All coils are shielded in
plated housings, and string tuning indicator mechanisms are replaced with steel wire. These components are as
uncorrupted as they were when they were made in 1960. The designers gave extra attention to the quality of
everything the customer would see and feel (the knobs play very well). From the John Eckland Collection, Palo
Alto, California. Photo by Caleb Brown.

engineers from radio. Hams performed feats of moon bounce communi-
cations and even made a series of Oscar repeater satellites. Imagine that,
a group of civilians building satellites that NASA launched into space for
free. I myself have heard aurora skip signals on the 6-meter band—the
bouncing of signals off the northern lights. All this in the days of early
space travel and Star Trek. Some fun.
Soon after transistor radios were common, industrial transistors became
cheap and available in volume. The hobby books were out with good cir-
cuit ideas in them, so I finally started making transistor projects about
1966.1 was a bit reluctant at first, because the bipolars were delicate,
physically and electrically, and had poor gain and frequency response.
Tubes were still superior for the hobbyist because of their availability. You
could salvage parts from radios and TVs found at the dump, or discarded
sets awaiting the trashrnan. Because the circuits were relatively simple, we
would dismantle old sets right down to separated components and chassis,
which would be reassembled into the next hobby project. I began to tap
the surplus parts suppliers, and the added supply of tube and related parts
delayed my interest in solid-state circuits.
The first commercial transistors were germanium PNP, and they
sucked. They just wouldn't work correctly at high temperatures, and their

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