Assertion: tube | /r/HasAspect | center-tapped heater
Facets:
Source sentences:
text: The initial "12" in the designator implies a 12-volt heater requirement; however, the tube has a center-tapped heater so it can be used in either 6.3V or 12.6V heater circuits, and in most current (as of 2018) applications is used in 6.3V circuits.