2 x 12AY7 Dumont Tubes. Tested on enhanced Triplet E3444 Laboratory Tester. Bogey(100%25) = 1700/1700 micromhos @ 3.0/3.0 mA +/- 10%25. The test is of actual transconductance (gm) with the tube under the quiescent conditions specified for it.
Tested on an enhanced Triplet E3444 Laboratory Tester prepared by Paul Hart of Roswell, GA. Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. Results =5100%7c2290µmhos ~32mA.
Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. Industry Bogey plate current = 9.0%7c9.0mA. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^.
Type 6CG7 vacuum tubes. One matched pair, circa +/-1960, U.S.A. made by RCA. Acid etched designations (RCA's emblem) Tubes feature gray ribbed plates, gray shields between anodes and top-mounted halo-ring getters construction.