5881 beam tetrode valve edicron 5881wxt beam tetrode valve pentode valve octal ao8 base 6 3v heater voltage 0 88a heater current 73ma anode current 250v anode voltage 39 5mm diameter 5 8w power a very reliable beam tetrode valve housed in a full size octal base designed and built to a rigid military standard this valve will tolerate higher voltages than other valve of this type low screen grid current for high efficiency low third harmonic distortion good choice for general purp