More playing with crt's, this time dg7 32 vinatge scope tube

I have a old 'scope tube as per the thread title.

I have connected it up to a power supply to see if I can get a dot before going further.

The voltages for the best dot are as follows:

Kathode -200v
g1 -245v
g3 -180v
anode 290v
heater 6.3vdc

All deflection plates shorted and connected to the anode.

The brightness control does very little, the focus control does work and has a 'best point', but the smallest I can get the dot is 3mm or so.
I have 2 tubes and they are the same, not new salvaged.
I'm thinking maybe the cathode isnt negative enough.

Sussed it.
Voltages were correct, it wasnt the volts it was the lack of smoothing.
I paid the price for parts mining, turns out my negative supply cap was high resistance, my esr meter didnt even show a reading.
I temporarily shoved a photo flash cap in there and I can now get the dot down to less than a pinhead.