ECC81, Telefunken, Berlin Manufacture, August 1963

ECC81, Telefunken, Berlin Manufacture, August 1963

On offer today is a lovely Telefunken premium quality ECC81 carrying the date code for August 1963.       Carrying good faded white print, it tests as excellent using my AVO Valve Characteristic Meter VCM163 with the following results: At Va = 250V Vg = -2.0V 

Section 1: Ia = 10.5 mA; gm = 5.2 mA/V

Section 2: Ia = 10.5 mA; gm = 5.2 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 valve with excellent matching of each triode section within the envelope.