AR63 Excitron

[ppppenguin]

Many years ago I bought an AR63 Excitron at a vintage wireless event. Some data here: https://www.valvecollector.uk/cv3710.htm  It's been a nice display piece siince then. The other day I was pointed to this Youtube video, showing a similar Excitron in action:
https://www.youtube.com/watch?v=OU4UOjGQhzM

So I thought I'd have a go at running mine. Unfortunately I can't even get the exciter to strike an arc. I'm using a bench PSU, 0-30V, 0-5A both variable, plus a magnet to lift the "dipper". But I can't get the arc to strike. I get a nice blue flash as the dipper comes out of the mercury pool but nothing thereafter.

Perhaps the valve is down to air?

The exciter circuit was a screen grab from the youtube video. I think it's taken from a Marconi transmitter manual.

[Ed_Dinning]

Hi Jeffrey, from memory I believe you also need anode volts present so that the main arc will strike and maintain.
Dipper is only to provide some initial ions

Ed

[ppppenguin]

At the moment I can't even get the excitation arc to strike and maintain. Because it's a grid controlled device the main arc can be switched on and off at will. But I'll try with some volts on the main anode in case that encourages the excitation arc to strike properly.