Truetone D941, 1940
Tube complement: 12SA7 mixer/oscillator, 12SK7 IF, 12J5GT detector, 12SQ7 1st audio, 35L6GT audio output, 35Z5GT rectifier.
Approximately 11 inches / 280 mm wide.
My radio's chassis matches the "Issue B" version of the schematic, dated October 1939. It differs from "Issue A," dated seven months earlier, in that a permanent-magnet speaker substitutes for the earlier electrodynamic (with field coil) speaker. To compensate for the missing field coil's inductance in the power supply filter circuit, the designer added a third section of power supply filtering, and removed the electrolytic condenser that was bypassing the audio output tube's cathode resistor. This last change was probably made to reduce the amplifier's low-frequency response, rendering the residual hum in the radio less audible.
I've called this a 1940 radio because the schematic is dated Oct. 1939; no doubt it would have taken at least two or three months to get the schematic changes into production and fill the distribution channels with "Issue B" product.
According to labels affixed to three replaced tubes, they were replaced on February 22, 194? (the last digit is unreadable) by Homer F. Saville, "Certified Radio-Trician," Blanchester, Ohio. This radio joins a few others in my collection that are operating on the original electrolytic filter condensers. I did have to replace a few of the original paper condensers because they were leaky.
I sometimes receive e-mail from people looking for this or that particular cosmetic radio part (such as a dial, pointer or escutcheon). Except in rare cases (such as for common and collectible Zenith models), original or reproduction parts for old radios aren't available. One really shouldn't buy old radios that are missing cosmetic parts with the hope of ever securing replacements. One has to be willing to do what I sometimes do: In the case of this Truetone, which is very difficult to find in complete, excellent condition, I bought not just one but two additional radios from which to fashion one near-perfect example. For more information on sources for original and reproduction cosmetic parts, see Help.