Price is for 1 little used, but tested tube. Produced in the US by SYLVANIA. This is special version and full equivalent of ECC82 - 12AU7 type. With long gray plates and single square-getter.
Test VERY STRONG & BALANCED as follow:
Ia1 = 9.1 mA | S1 = 2.0 mA/V | Ri1 = 8.4 kOhm | μ1 = 16.8
Ia2 = 9.2 mA | S2 = 2.0 mA/V | Ri2 = 8.5 kOhm | μ2 = 17.0
Tested under: Uf = 12.6V | Ua = 250V | Ug1 = -8.5V
Good starts at Ia=7.0mA
Shipping will be Airmail registered with tracing number. Other shipping methods available on request.