Learning about vacuum tubes, and need advice on high voltage power supplies

[daflory]

Hello everyone,

I am an EE student and would like to experiment with vacuum tube devices this summer. I have some interesting VFD glass I'd like to learn to drive and would also like to experiment with thermionic rectifiers and amplifier circuits.
I need advice for how best to generate the high bias voltages I'll need. I am not ready to build a linear HV PSU from scratch and appropriate PSU's seem to be very rare and expensive even on the used market.
Please correct me if I make any errors, but it looks like two independent 100V adjustable @ ~150mA would be adequate to study the operation of most common tubes. I don't need high power output.
All the tube power supplies I've seen are linear, and I assume there's a reason for that. Are voltage doublers and boost circuits acceptable for my application?
Lastly, I'd appreciate any advice for how to safely measure high voltage output with an oscilloscope.

[MarkF]

I don't do vacuum tubes but this "Big Iron" video seems like a good start point.

[vk6zgo]

By & large, you can get away with a fairly simple linear supply for  vacuum tubes.
In most cases, regulation is not required, the main thing being to get hum as low as possible.

100v would probably be OK for normal "playing about", but a bit more would be useful.

Yes, voltage doublers can be used for higher voltages, & were commonly used in the last generation of tube TVs.(at least in Australia)

If you could pick up a domestic radio with a transformer power supply, you could use that.
Unfortunately, such things are a bit rare in North America, due to US manufacturers' love affair with the "All American Five" type of transformerless radio.

In Oz, those things were commonly known as "death radios"!

[MarkF]

This looks promising:  Stancor P-8624 power transformer

[ivaylo]

https://youtu.be/mEFdADrU9MA

He needs -300V here, but same principle of construction applies for your case, just find a proper transformer.