The 41MHL is an indirectly heated triode and was suitable for detector or audio amplifier in a radio receiver.
Quite often Cossor valves are identified by V9 or V5 these are maker codes and not Type designations.
Our other 41MHL's are in balloon envelopes and one is metallised. See41MHL for details of the inner structure.
The dome carries the Cossor name and the V9 code as well as BVA and Made in England. Inside can clearly be seen that two grids are present the inner grid with a finer winding pitch.
The top mica and grid supports.
The classic envelope is 49 mm in diameter, and excluding the B5 base pins is 113 mm tall.
References: Data-sheet, 1043, 3002 & 1040. Type 41MHL was first introduced in 1930. See also1930 adverts.
