Motorola Model 10T28M Radio

My wife found this tube-powered AM/FM set for me. Guessing by the "jet-age" styling, it must have been made in the late 1950s or 1960s, although there's no date on the label and this radio doesn't appear in my collector books.

This is a high-quality radio. Dual speakers, plus sturdy construction and a solid mahogany cabinet, make it very heavy for its size. Inside are eight tubes (6BE6, 6BA6, 6BA6, 6AU6, 6AL5, 6AV6, 6AQ5, 6X4) plus the EM81/6DA5 magic eye tube.

My favorite feature of this radio is its magic tuning eye (not glowing in this photo), which appears in a little window to the right of the dial, right above the "batwing" Motorola logo.

Magic tuning eyes were quite popular in the 1930s and 1940s. The green glow begins at each side of the tube, and as you home in on a station. the glowing parts gradually meet in the center, making the brightest glow. Tuning eyes are usually connected to the AVC (automatic volume control) circuit, which maintains a reasonably constant audio volume for radio signals of different strengths.

This radio has good tone, thanks to the dual speakers, The tuning dial tends to slip a bit, however. I spent a little time cleaning the mechanism when I got the radio. But I need to go back and put some rosin on the dial cord. The stringing scheme is fiendishly complex, wrapping around the side of the chassis as well as the front. A second, shorter cord comes off the main string pulley and disappears into a little shielded box mounted on top of the chassis.

The little cord moves very slowly in relation to the main cord, so I assume it's moving some widget (a small potentiometer?) inside the shielded box. Perhaps because there are so many contact points and moving rollers, the string is under a lot of tension—it twangs almost like a guitar when you pluck it!

After owning this radio for a couple of years, I sold it at a local swap meet. The new owner was very happy to acquire it.