A NOS Brimar ECC81 tube in good working order.
It has been tested on an Avo Mk3 Valve Tester which can determine both plate current and transconductance and it tests very strong.
Actual Readings
Triode 1
ia (mA) - 15
GM (mA/V) - 6.4
Triode 2
ia (mA) - 13
GM (mA/V) - 5.9
Data Book Specification
ia (mA) - 10
GM (mA/V) - 5.5
skuV14
