Radiophile.com - Meck DA-601 & Aircastle 9008

Meck DA-601, 1949

Approximately 7 inches / 18 cm wide.

Tube complement: 12BA6 RF amplifier, 12AT6 detector, 50B5 audio output, 35W4 rectifier. A simple and cheap TRF circuit.

The Sams Photofacts service info for this model shows the audio output tube to be a 50C5, while this example uses the earlier 50B5. There were a number of component value differences from the schematic too, and a miswire in the 35W4 filament circuit. The set appeared to have been wired that way at the factory—it worked, but not as well as it did after I corrected the wiring. As far as the component value changes, I bet John Meck Industries just used whatever WWII-surplus components they could get their hands on cheaply. In most circuit applications, any value near optimum will work with negligible performance degradation. Some of the original resistors under the chassis were the old, pre-WWII-style body-end-dot dog-bone shaped units. I bet those were cheap—maybe even free—in 1949.

Aircastle 9008, 1949

Approximately 7 inches / 18 cm wide.

Tube complement: 12BE6 mixer/oscillator, 12AT6 detector, 50B5 audio output, 35W4 rectifier. A simple and cheap superheterodyne circuit—the IF-amplifier stage has been omitted for low cost and poor sensitivity.

This radio's chassis is the same metal stamping as used in the Meck DA-601 above. Empty holes in the Meck's chassis are filled with a single IF transformer on the Aircastle chassis. Change the tube complement just slightly (substitute a 12BE6 converter tube and circuit for the 12BA6 RF amplifier) and you get a superheterodyne instead of a TRF circuit. Both chassis have an unfilled hole for a fifth tube—apparently Meck also used this chassis to make a full-fledged All American Five receiver.