Quick Heating ValvesA range of single and double transmitting tetrodes was introduced in the early 1960s for use in mobile equipment. These valves are of the directly heated type but have a very low filament voltage of the order of 1.1 volts and cannot be operated directly from a 6 or 12 volt car battery. The valves themselves have characteristics similar to the normal indirectly heated types. The filament is energized from additional centre tapped windings on the transformer of a transistor DC to DC converter. These windings have a rectangular output waveform, the RMS value of which is half the peak to peak amplitude. Use the Back Button on your Browser to return |