RCA Victor 8X521, 1948
Tube complement: 12BE6 mixer/oscillator, 12BA6 IF, 12AT6 detector, 50C5 audio output, 35W4 rectifier.
The red dial indicator glows brightly when the radio's on.
This set continues the RCA tradition of superior circuit design. (See the RCA Victor 66X3.) Even though it's just a plain-jane simple five-tube ac/dc circuit, RCA couldn't resist adding an extra, quality touch: The oscillator coil has an adjustable core which is adjusted like a padder condenser would be. It is used to calibrate the dial at the low-frequency end, in addition to the normal trimmer adjustment at the high-frequency end, for accurate frequency calibration across the whole dial range.