There’s no doubt that PC board production methods simplify production line manufacture. However, with valve radios, there was the problem as to how to mount the heavy power transformer. Mounting it on the PC board wasn’t really a proposition, since the board could easily be cracked if a minor mishap occurred in handling the receiver.

For this reason, the power transformer was usually mounted either on a small metal sub-chassis (eg, as in the Healing 412E mantle receiver) or on a substantial chassis which also accommodated other heavy items (eg, as used by Admiral). In the latter case, the PC board was mounted in a cutout on the chassis.

Healing 412E

Fig.1: the circuit uses three valves: a 6BE6 converter, a 6N8 IF and detector stage, and a 6BM8 for the audio output stages. The power supply consists of a transformer and a half-wave solid state rectifier.

The Healing 412E is a small mantle AM receiver which used three valves: a 6BE6 converter, 6N8 IF and detector stage, and a 6BM8 for the audio output stages. The power supply consists of a transformer and a half-wave solid state rectifier – see Fig.1.

The dial system on this set is rather crude, being a direct-drive system with the tuning knob mounted on the end of the tuning gang spindle. I had expected that it would be touchy to tune but the knob is big enough to make tuning easy. The dial leaves a bit to be desired, however – it consists of nothing more than a piece of glued-on cardboard with station markings (some radios apparently have the dial calibrated in frequency only).

My radio has no cover over the dial although some units were fitted with a clear plastic cover.

In this set, the power transformer was mounted on a small sub-chassis at the righthand end of the cabinet (as viewed from the front). A PC board running across the remainder of the cabinet width took care of most of the circuitry, while a multiple-turn loop antenna was wound on the back wooden board cover of the receiver. Interestingly, the more fashionable loopstick antenna was not used in this set.