Oscillator: "AD9850 signal generator module. "
osc
Amplifier: 500 volts peak = 1000 volts p-p = 1200 volt supply.
This transistor has no speed rating and may be slow. It is only 1200V. There are not many HV transistors in production now.
STN0214
Here is another but I know it is too slow.
STP03D200
I have some old stock 2kv transistors that are not available from suppliers. I think we got 100khz and 300V out of them.
MOSFETS: HV and low current. mosfet Here is an example of a part.
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500v ac 500khz will burn. It will peal the skin off your finger. I have seen and had burns from this. It is very dangerous. At that frequency you do not have to have one hand on ground to get hurt. If some one is going to build this it needs current limit!

I have a bad feeling about this. It actually sounds like a device to wring confessions out of prisoners. I don't care for the evasive answers either.

 

amplifier
low voltage high current

 

EL34 might get nearer 1MHz than a MOSFET with only 16pF input capacitance, and 1.2pF output capacitance!
https://shop.ehx.com/catalog/addimages/el34eh.pdf
and if you don't mind something that's obsolete
6DQ5 with an anode cap to increase the insulation on the HT.
https://frank.pocnet.net/sheets/127/6/6DQ5.pdf

 

and if you don't mind something that's obsolete

IanO you crack me up. Why is it when I suggest a component that is discontinued or "obsolete" in your opinion it's a mediocre design but if you suggest one it's OK? Maybe because it gets the job done?
SG

 

I suggested one component that was in current production, and one that is obsolete but still available, and cheaper. That way, whoever is designing it can choose. It depends a lot, as I learned from the previous topic (probably from you), whether it is intended to make a single unit, or a production run. My mindset is normally to design something that can be built 50, 100 or 1000 times without supply problems. There may be other people who are happy to build one with no intention of ever building another.

 

EL34 might get nearer 1MHz

The goal is 500V peak and the max plate voltage is 800, 900V. (?)

 

And if it's in a push-pull circuit, or inductively loaded it can swing to almost double that. There's another parameter called Va(0) - the anode voltage with no current flowing - which is 2kV

 

You did not answer the question.
We know that you want to generate sine waves 1Hz-500kHz, 5mA-10mA @ 100V-500V.
What are you going to do with it?

Medical device

 

If I was unwell, I wouldn’t like to be connected to it!

 

Medical device

My crystal ball is working well! (post #19)

Bob

 

Medical device

Sorry, that is a prohibited topic as per User Agreement.