Type 6J7 was originally designed as a detector, however, its linear characteristic and good internal shielding (cf. 6Q7G) made it a natural choice for audio.It was for two decades the international standard valve for audio amplifier input stages and audio systems generally. The Mullard-Philips type EF37A, for many years the standard British low-noise audio pentode, is really a 6J7G under another name.This exhibit was made for the UK Air Ministry and has this identification on the base cap.
The original valve identification on the glass.
The old stores code of 10E/352 appears on the base cap.
The NAPL logo - a testing station?
The perforated anode screen and below and above the screening continues. The classic envelope is 38 mm in diameter and, excluding the IO base pins, is 99 mm tall.References: Private communication & data=sheet. Type 6J7G was first introduced in 1936. See also 1936 adverts. |
