Radiophile.com - Belmont 534

Belmont 534, ca. 1941

Tube complement: 12SA7 mixer/oscillator, 12SK7 IF, 12SQ7 detector, 35L6GT audio output, 35Z5GT rectifier.

Approximately 12 inches / 30 cm wide, including side tuning knob.

Belmont produced this radio both before and after WWII. The post-WWII production was labeled model 5D128. I can tell this one was made pre-WWII from the types of parts used in its construction. Most telling is the use of the old-style resistors with the wires wrapped around each end (dogbone style) and body-end-dot (see sidebar at right) color coding.

This radio uses a variation of the ubiquitous All American Five circuit. In the normal AA5, the filament voltages of the five tubes add up to the 120-volt AC line voltage, more or less. In this radio, a 35L6GT audio output tube is used instead of the normal 50L6GT, so the filament voltages add up to only 106 volts. The additional voltage drop occurs in an under-chassis resistor. Why did the designers choose the wrong tube? Even though the 50L6 was introduced in March 1939, just one month after the 35L6, the 50L6 must have either been more expensive than the 35L6 (by an amount greater than the cost of the resistor) or have been on allocation due to scarcity (which is really the same thing as costing more, as scarcity plus demand equals a higher price always; we radio collectors are surely familiar with that phenomenon). I've encountered many early-1940s radios with this same imperfect tube complement, no doubt for this same reason.

Body-end-dot
In the old days, before it became practical to actually print numbers on the bodies of small electronic components, color-coding schemes were devised. In the "modern" color-coding method (still used today when color coding is necessary), there are three color bands around the resistor body that indicate its value. The first two bands signify the two significant digits of the resistance value, and the third band signifies the multiplier. Before this identification method came into use, a common method was body-end-dot labeling. Here, the color of the body of the resistor signifies the first significant digit of the value. One end of the resistor is painted a color that signifies the second value digit, and in the center of the resistor body is a dot that signifies the multiplier.

Here's the first page of the radio's instruction sheet.

[User guide, first page]