Sensibly equivalent¶ to:
The Mullard EF91 was almost the universal amplifier pentode of the post war era, many manufacturers made versions of this standard valve. Here we have a Mullard made valve but with a Type of 6AM6 - another name for the same design specification.
The 6AM6 is a high gain, high impedance, variable μ, screened pentode. It could be used from AF to VHF up to about 200 MHz and was found in large numbers in most types of electronic equipment. In radio it was used for RF and IF amplification, for oscillators and frequency multipliers.
The anode side view, the strap linking both halves of the anode can be seen on the left.
The white bands at the rear are reflections. The screen and suppressor grids can be seen easily but the control grid just looks like a series of straight lines of a much tighter pitch.
This enhanced image makes the control grid much easier to see.
The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
References: Datasheet, 1043 & 1040 Type 6AM6 was first introduced in 1947.
Absolute Maximum Operating Conditions¶
Updated May 24, 2013. shape:thin.glass.tube construction:all.glass type:pentode age:1940.1950 base:b7g heater:6.3v pins:7 pin:1.g1 pin:2.k pin:3.h pin:4.h pin:5.a pin:6.g3 pin:7.g2