Enclosed a look at a 75KW Eimac klystron frequency range 450 to 900mgh 10 meg bandwidth, driven with 3KW power klystron. This tube has 40% efficiency and you need two heat exchangers at 86 gallons per minute in parallel to cool it. It is sitting in the bottom half of an aluminum shipping cage which most of us cannot afford. Cost was 40K shipping not included
The weight was 1200 pounds. You would need a house and a barn to house the support equipment. The person standing next to the tube can give you every minute detail known to man about making these beasts work without failure. These were used on certain portions of the Dewline.