In general, transmitting tubes adopt concentric cylinder electrodes. The cathode is in the innermost layer and outward is each grid electrode and the anode in turn.
Transmitting tubes of medium and small power mostly adopt indirect heating oxide cathodes and high-power ones usually adopt thorium tungsten carbide cathodes which are in shape of vertical bar, cylinder mould and spiral.
The grid electrode is fired from molybdenum wire or tungsten wire. It can be also manufactured in the way of electroprocessing molybdenum fragments.
The tube is made of glass or ceramic. Small-power transmitting tube uses baric getter while high-power tube adopts getter materials like zirconium, titanium, tantalum.
