This is Part 1 of the build process of a kilo-watt valve/tube HF Linear Amplifier.
IMPORTANT: Without proper safety procedures and protection, the High Voltages involved will cause Death or Serious Injury.
HT transformers are hard to find and expensive, so a modified microwave oven transformer will do.
(No, this not about spot-welding .....)
Cost is always an issue, so do not expect to see a 4CX1000A !
The aim is to use a GU-81M tube which is much cheaper and looks way sexier.
As a guide, EX8A has a cool design (in Russian): http://www.cqham.ru/HiFi_Contester_EX8A.htm
For all things tube-based, check out the superb resources published by PA0FRI: https://pa0fri.home.xs4all.nl/Lineairs/Frinear1500/FRI1500eng.htm
For professional transformers custom-made to your specifications, contact EA7YB.