this is pretty much the only western documentation about modding the PNW-57e, so i thought i share my 5cents about the alternative power supply shown on the previous page.
First an for most: This is a High Voltage Application that can easily kill you!
Near 20kV with mA strength is nothing that should be done without deep Knowledge about what your doing!
According to some Russian Documents the Alkali Photo Cathode is working at about 18kV DC and is behaving like a capacitor, the original circuit is charging it up and waiting til the voltage drops again, than it starts to pulse again. I measured about 1,35kHz with 14V AC on the primary side. I know nothing about the power consumption on the secondary side, it seems to be in the uA range? All in all a really nice solution to save energy and extend the lifetime of the tubes.
Back to the self-made solution: CCFL Circuits vary form 300V to 1kV - you should know what you have in front of you. The Cockcroft-Walton Multiplier should have as less stages as possible, 13 seems fine for a 700V CCFL. The Capacitors must withstand at least twice the input Voltage. If you use a 1kV CCFL, you need 2kV Capacitors! 500V is far to less! Same for the diodes. Having a Resistor behind the Multiplier is a bit BS, instead i would rather cut down the size of the Capacitors to bring the Current down to a less deadly amount. I will start with 5pf for my first test, the ccfl is much faster (30kHz) than the original transformer, so it should be able to keep up with charging even with smaller capacitors - if i survives i will report again, 1nf seems to be far to much.
There is a negative Voltage power supply shown, the original circuit is a positive one, i would prefer to keep ground on ground potential and the high potential at the inside
Isolate that shit! Solder the Coax Cable to the Multiplier! Insulate that shit again
and expect arc ranges up to 2 cm if the isolation fails! I would embed it in resin too, including the cable. I could not find a suitable Cable with 20kV Voltage, but solid PTFE Coax Cable should do the job with about 40kV isolation per mm in theory.
Again: this post is all about sharing ideas and information, it is not meant to be an Instruction in any way!
I still prefer to use the original Transformer and Multiplier together with the Driver! This is much saver than dealing with Voltages no one can measure exactly and lots of unknown specs of the tubes.
If someone has better and more detailed Information, thank you for sharing it too
Maybe we can find something save to use.