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Indeed many early examples of the All American Five were downright lethal. The radio was designed from the start to eliminate the need for a mains transformer (a relatively expensive item). As a result, the chassis of the radio was directly connected to one side of the mains electric supply. The metal chassis securing screws were often accessible from the outside of the bakelite or wood case, and there were many examples of owners electrocuting themselves on making contact with these screws while handling a set.
The hazard was made worse because the on/off switch was usally in the ground wire of the mains supply (this saved a terminal lug (and, more importantly, a couple of cents)). This meant that the chassis was live when the set was either 'on' or 'off' - which depended on which way round the plug was inseted in the power outlet. This hazard was eliminated from later sets, by ensuring that these screws were not accesible from outside of the enclosure, but the hazard was still present to service personnel.
Many design tricks were used to reduce the cost. The heaters of the tubes were all rated to use the same current, but the operating voltages were designed to add up to (as near as dammit) 120 volts. Thus the heaters could be connected in series and then connected directly across the mains electric supply. Like christmas tree lights, if one tube heater failed, the lot went out.
The radio used a simple half wave rectifier to produce about 160-170 volts of plate voltage. The plate current was even routed through half of the rectifier heater to balance up the current in the other half which had the dial light connected across it. Indeed the failure of the dial light will cause premature failure of the rectifier in a matter of hours.
The frequency convertor was of the pentagrid design to save the cost of an extra oscillator valve.
The Radio was called the All American Five because all the examples manufactured were all made in the USA. They were manufactured in the millions by hundreds of manufacturers from the 1930's all the way through to the end of the tube era.
Although a 4 and 6 tube versions were produced, the 4 tube was of considerably inferior performance (and the 5 tube version was not that good to start with). The 6 tube version cost sufficiently more, that it did not sell well.
For the technically minded the tube line up in the early days of the Octal tubes was:
Converter 12SA7; IF Amplifier 12SK7; Detector and First Audio 12SQ7; Audio Power Output 50L6; Rectifier 35Z5.
In the 1950's the set was redisigned to use miniature 7 pin tubes and the line up became:
Converter 12BE6; IF Amplifier 12BA6; Detector and First Audio 12AV6; Audio Power Output 50C5; Rectifier 35W4.
A number of other versions of the set set appeared, including some that did have a transformer, a version that operated in a motor vehicle off of a 6 volt supply and even a version that operated from either dry batteries or the mains supply.