Price is for 2 NOS dual triode tubes. Super rare and one of the most-desired dual triodes ever made. It's early production from the 1950s with so-called short base.
Etched codes - 5K2 6H3 / 5K2 6H4
Test VERY STRONG as follow:
Tube 1
Ia1 = 8.9 mA | S1 = 3.8 mA/V | Ri1 = 9.8 kOhm | μ1 = 37.2
Ia2 = 9.6 mA | S2 = 4.1 mA/V | Ri2 = 9.1 kOhm | μ2 = 37.3
Tube 2
Ia1 = 9.3 mA | S1 = 3.9 mA/V | Ri1 = 9.5 kOhm | μ1 = 37.1
Ia2 = 11.9 mA | S2 = 4.3 mA/V | Ri2 = 8.2 kOhm | μ2 = 35.3
Test under: Uh=6.3V | Ua=250V | Ug1=-4.0V
Where 100% is Ia=9.0mA and S=3.6mA/V
Shipping will be Airmail registered with tracing number. Other shipping methods available on request.