Sensibly equivalent¶ to:
The EF80 internally screened pentode was a workhorse of the VHF TV receiver and was introduced in 1950. It was described by Mullard as: a high slope RF pentode and not a variable μ type. The EF85 was the variable μ counterpart to the EF80. This example is marked with the reseller's branding.
The electrodes only occupy a part of the envelope, the top space is coated internally with the getter.
The thin glass tube envelope is 20 mm diameter and excluding the B9A base pins, is 58 mm tall.
References: Data-sheet & 1040. Type EF80 was first introduced in 1950.
Absolute Maximum Operating Conditions¶
Updated December23, 2013. shape:thin.glass.tube construction:all.glass type:pentode age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.k pin:2.g1 pin:3.k pin:4.h pin:5.h pin:6.s pin:7.a pin:8.g2 pin:9.g3