The FC13 is an octode frequency changer. It was made in two versions, the FC13C on a B7 base and this version on a Ct8 base.
This exhibit although given the Mullard brand name was made by Philips, the parent company, in Holland. The Ct8 base was much more popular on the Continent than in the UK.
In use the local oscillator would be formed between the cathode and grid 2 with g1 as the oscillator control grid. The signal would usually be added at g4, connected to the top cap. Grids 3 and 5 are the screen grids and grid 6 is the suppressor.
Such golden external metalised valves can be seen in radio sets from the late 1930s and early 1940s and the FC13 was listed in the 1934 Mullard catalogue.
The reverse is plain screening paint. The maker's code is printed on the base cap.
The classic envelope is 48 mm in diameter and, excluding the Ct8 base pins, is 115 mm tall.
References: Datasheet & 1043. Type FC13 was first introduced in 1934.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated December19, 2018. shape:classic construction:pinch type:octode age:1930.1940 base:ct8 heater:200ma pins:8 pin:1.m pin:2.h pin:3.h pin:4.k pin:5.g2 pin:6.g1 pin:7.g3.g5 pin:8.a pin:tc.g4