Hum

[Domenic M. Mallozzi]

Hi

I don't think this is realy off topic because it applies to all point to
point wired receivers.

On many old radios rivets were used to make the ground connection to chassis
for terminal strips. Than the components you wanted to ground were soldered
to the terminal strip lug that was grounded. I have had a couple of sets were
the connection made by the rivet had gone away after lo these many years.
Sugget you check with a ohmmeter to see if these points are really grounded.