Hi All - No, not a 5763, I'm looking for a 5736. Its a Westinghouse large external copper anode triode from the early 1950s. Can run 5,000 volts at 1 amp on the plate. Has a gain of 12 so you would need a 400 watt driver to get its full 5 kw out. Big, heavy, and a neat looking bookend. Was used in several commercial applications decades ago. 73 Bob W7AVK