Price is for 1 maybe NOS and tested tube. This is very early produciton ECC81 type from the late-1950s. With Yellow-T marking, square getter and black boxy plates.
Tested VERY STRONG as follow:
Ia1 = 10.8 mA | S1 = 5.6 mA/V | Ri1 = 10.2 kOhm | μ1 = 57.1
Ia2 = 13.2 mA | S2 = 5.7 mA/V | Ri2 = 8.1 kOhm | μ2 = 46.2
Tested under: Uf = 12.6V | Ua = 250V | Ug1 = -2.0V
Shipping will be Airmail registered with tracing number. Other shipping methods available on request.