Antonio Vernucci wrote:
Another idea would be to connect an rf voltmeter to the antenna
connection and just tune for max rf voltage.

I found THE solution to measure current flowing though a wire at high
potential without risks!

Solution is to use an Hall-effect transducer of the same type used in
the newer clamp meters (those able to measure both AC and DC currents).
One can order transducers with full-scale currents ranging from as low
as 10mA to tens of Amps. The high-potential wire passes through a hole
having a diameter of two centrimeners, so it is fully insulated from the
measurement circuitry,

The transducer can directly drive a meter having a full-scale current of
20 mA or less. See http://www.chenyang-ism.com/

73

Tony I0JX

If the plate supply has it's own power supply with a separate power
transformer or winding the meter can be placed in the negative lead of
the power supply. Be sure to place the meter outside of any bleeder
resistors so you don't measure the bleeder current.