The 6GH8 (More commonly labeled as the 6GH8A)is a nine pin miniature vacuum tube, produced as a combination of medium-mu

Triode A triode is an electronic amplifying vacuum tube (or ''valve'' in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode). Developed from Lee De Forest's 19 ...

and sharp-cutoff

Pentode A pentode is an electronic device having five electrodes. The term most commonly applies to a three-grid amplifying vacuum tube or thermionic valve that was invented by Gilles Holst and Bernhard D.H. Tellegen in 1926. The pentode (called a ''tripl ...

. It follows that the tube is divided into two sections - anode and cathode. Each of the sections had separate cathode. Commonly this type of tubes are used in

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

and

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...

receiver. The basic application of the tube is in multivibrator-type horizontal-deflection circuits, AGC-amplifier and sync-separator. They were most common and popular in RCA's CTC line of

color television Color television or Colour television is a television transmission technology that includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white t ...

sets, as color demodulators. They were infamous for their failure, and therefore, often needed replacing. Other RETMA triode/pentode combinations with a 6-volts heater include: 6F7, 6P7, 6U8, 6X8, 6X9, 6AG9, 6AH9, 6AN8, 6AT8, 6AU8, 6AW8, 6AX8, 6AZ8, 6BE8, 6BH8, 6BL8, 6BR8, 6CG8, 6CH8, 6CM8, 6CS8, 6CU8, 6CX8, 6DZ8, 6EA8, 6EB8, 6EH8, 6EU8, 6FG7, 6FV8, 6GE8, 6GJ7, 6GJ8, 6GN8, 6GV7, 6GV8, 6GW8, 6GX7, 6HB7, 6HG8, 6HL8, 6HZ8, 6JA8, 6JC8, 6JN8, 6JV8, 6JW8, 6KA8, 6KD8, 6KE8, 6KR8, 6KT8, 6KV8, 6KY8, 6KZ8, 6LC8, 6LF8, 6LJ8, 6LM8, 6LN8, 6LR8, 6LX8, 6MG8, 6MQ8, 6MU8, 6MV8

References

{{reflist Telecommunications-related introductions in 1973 Audiovisual introductions in 1973 Vacuum tubes