Many radios have a pair of capacitors that go from each side of the
power line to the chassis. They are put there to prevent RF from
coming into/out of the power cord. In the best of conditions, they
put the chassis at 1/2 the power line voltage above ground. That is
low enough not to hurt you, but high enough to make the chassis feel
"buzzy" when you slide a finger across the metal.

Add a 3 terminal power plug/cord to the radio, and connect the green
wire directly to the chassis, and the tingle will go away.

-Chuck Harris

geojunkie wrote:
I have an SX-71 in which I replaced the paper and lytic caps and still
have some stray voltage on the chassis. You can get a pretty good
shock under the right conditions. It was there before the recap and I
thought my resto work would have cured it. What could be causing this?
Also notice this on an older SX-16 that hasn't been recapped yet.

Dan