Frank, PA3CNO, brought in a homebrewed Power Amplifier with PL519 tube designed for QRO use on the HF bands.
The DC Power Supply provides 1100 Vdc (loaded). The design is from Frits PA0FRI. With some minor modifications (change of input circuitry and ATU coil) Frank managed to get 150 Watts PEP (!) out of this rig. The PL519 tube was used in old TV sets and is still available at radio- and fleemarkets.
PSU, 1300Vdc unloaded, 1100Vdc loaded
Look for the QRO section on http://www.pa0fri.com/