Emerson 540A restoration

[Reece]

The whole business of making AC/DC radios safe leads to a series of compromises. If you have a true hot chassis set, you have a chance of the chassis being hot depending on how you plug it in. With a polarized plug routing neutral to the chassis, you're OK as long as your house receptacles are wired correctly. Most sets have the power switch piggy-backed to the volume control: it's better for hum reduction to have the neutral line switched but that would put the chassis hot. What most manufacturers ended up doing later on in the history of AC/DC sets was to use a floating ground with cap and resistor in parallel to chassis. You can still get a tingle from such a chassis, so to avoid that they used methods of mounting chassis where no exposed screws are hot or "warm," and lovely maddening captive knob arrangements like Zenith used. Another way I have used is nylon undercabinet chassis screws to replace metal ones on table sets.