This lovely little number is the EF80 pentode thermionic valve, or vacuum tube, made by Mullard beginning in 1950. They were used in radio and radar applications, but most of them wound up in VHF ...

Following are the different types of vacuum tubes and the elements used to control the flow of current. See vacuum tube. ----- VACUUM TUBES -----Triode Pentode Elements Diode Tetrode Cathode X X X X ...

A direct-conversion radio receiver required an audiogain of 450 from a pentode vacuum tube. A pentodehas a high transconductance—that is, the ratio of thechange in plate current to the change of the ...

Tube packaged in type 311A cardboard box. 311A crossed out and 310A written in pencil. A pentode with a 6-pin plastic base, top contact, domed glass envelope. Indirectly heated cathode. Heater voltage ...

A grid used in pentode vacuum tubes that suppresses interference or secondary electron flow caused by electrons that bounce off or are reflected by the plate. The suppressor grid sits between the ...