2 Vintage Hewlett Packard Holland 12AX7 A ECC83 Vacuum Tubes "I61". 1 is 12AX7 1 is 12AX7 A. Tested on our proprietary tester, the E3444 Triplett/Westmore 501.
It's a Triplett 3444 / Westmore 501 that has been enhanced. This tester uses regulated power sources for the bias, plate, & screen voltages, as well as modified operating & testing procedures. Filament voltage is also controlled. This tester was prepared by Mr.
Paul Hart of Roswell, GA. Industry Bogey transconductance = 1600/1600 µmhos &. Industry Bogey plate current = 1.2/1.2 mA. 1600/1465 µmhos 1.31/1.14 mA.
1740/1640 µmhos 1.48/1.31 mA. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Parts & Accessories\Vintage Tubes & Tube Sockets".
The seller is "greengirl613" and is located in this country: US. This item can be shipped worldwide.