ECC81, MATCHED PAIR OF MULLARD , YELLOW PRINT, BLACKBURN 1963/1965 MANUFACTURE

ECC81, MATCHED PAIR OF MULLARD , YELLOW PRINT, BLACKBURN 1963/1965 MANUFACTURE

On offer today is a lovely matched pair of Mullard YELLOW PRINT ECC81 Blackburn manufactured in 1963/65       Carrying good yellow print,they tests as excellent using my AVO Valve Characteristic Meter VCM163 with the following results: At Va = 250V Vg = -2.0V 

V1: Section 1: Ia = 12.0 mA; gm = 5.5 mA/V

V1: Section 2: Ia = 12.0 mA; gm = 5.5 mA/V

V2: Section 1: Ia = 14.0 mA; gm = 7.2 mA/V

V2: Section 2: Ia =12.0  mA; gm = 6.6 mA/V

The specification for a new/100% emission valve is:

Ia = 10 mA; gm = 5.5 mA/V

As you can see, this result show a strong pair of valves, well matched both inter valve and also showing excellent matching of each triode section within each envelope.