|Raytheon has a long history in gas-filled rectifiers.
This type, probably the most frequent type, can be used for voltages up
to 600 V at 200 mA (600 mA peak). Filament rating is 1.75 V at 2 A. System
voltage drop is about 12-15 V.
Although this tube can be used without external heating - the arc igniting
even with cold cathode and providing enough heat to get sufficient emission
- I recommend using it only WITH (pre)heated cathode. Cold ignition is
quite a rough process, the arc often blasts white glowing oxide particles
off the cathode. In unheated operation, the arc forms a very hot, sometimes
flickering emissive spot wandering over the surface of the cathode. With
heated filament, emission is very even and constant over the whole surface.
Here are two pics of this tube in my amp (4x EL 36 power tubes) in operation: