12BW4
The 12BW4 is a dual-diode tube where both diodes share a common cathode. The 12BW4 has a 12.6-volt heater. There is also a 6BW4, which is the same but with a 6.3-volt heater.
The 12BW4 is a dual-diode tube where both diodes share a common cathode. The 12BW4 has a 12.6-volt heater. There is also a 6BW4, which is the same but with a 6.3-volt heater.