12AT7 Toshiba, copper grid posts, black plates NOS (V133)

Beschrijving

12AT7, made by Toshiba in the Japan

This is a 12AT7  tube. The text on the glass indicates that the tube is produced by Toshiba in the Japan. The tube has a copper grid posts, a half box plate structure and back plates, see pictures. Healthy tube! Shows no signs of use.

Sonics

I have no information about the Sonic performance of this tube.

Test results*

The tube tests NOS. The internal balance between the triode sections is good. The measurement data below illustrate that the tube is in excellent condition. 

Valve V133

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

10,0 / 10,2  mA     5,3 /5,4 mA/V OK

=  NOS / NOS =  NOS / NOS

Where NOS is : Ia = 7 to 14 mA, Gm= 4,5 to 6,5 mA/V. 

  *  For test methods and factory specification read the tube testing page.

Short description