Heater voltage.

[ppppenguin]

When I was much younger in South London, we used to spend a bit of time in the transmitter rooms at Crystal Palace (under the hill). All the BIG capacitors there (mainly PIO ISTR), when not in circuit, had their terminals shorted otherwise the standing RF used to charge them up to lethal levels. We had a wooden "de-bollocking stick" which was used to ground or short out anything you were working on for safety, else death would be certain, quick but painful.

We have some big ex-transmitter capacitors at the Broadcast Engineering Museum. We make sure they are safely shorted out. We're not attempting to run our 40kW transmitter

We have an earth wand (ex Crystal Palace as it happens) but it's not yet connected.