The 6R from the Italian company Fivre is a pentode designed for IF amplification in superhet receivers. The closest match and pin compatible is the EF36 but differences exist.
The base cap skirt has the Fivre name and the word Balilla - little boy.
The wide glass tube envelope is 27 mm in diameter, and excluding the IO base pins is 78 mm tall.
Reference: 3002. Type 6R was first introduced in 1941.
Absolute Maximum Operating Conditions¶
Updated July 12, 2017. shape:wide.glass.tube construction:pinch type:pentode age:1930.1940 base:io heater:6.3v pins:8 pin:1.s pin:2.h pin:3.a pin:4.g2 pin:5.g3 pin:6.- pin:7.h pin:8.k pin:tc.g1