EL37, Mullard, Mullard High Speed Valve Tester, MHSVT, or a domestic receiver

EL37, Mullard, Mullard High Speed Valve Tester, MHSVT, or a domestic receiver

 Against the nominal AVO specification for 100% emission of :-

Ia =100 mA; gm = 11.0mA/V @ Va = 250V; Vg = -15V

Obtained results were:-

Device 1: Ia = 45 mA; gm = 5.0 mA/V 

As you can see, these results are lower than nominal but should give useful performance in a Mullard High Speed Valve Tester, MHSVT or a domestic receiver output stage = price adjusted accordingly.