Thoroughly tested on Hickok 539B . Hickok 539B is a mutual conductance (Gm) type tube tester. Cunningham 6L6 vacuum tube. One tube,circa 1948, U.S.A. made. <<<<<<< As pictured = The tube you see is the tube you get!
Thoroughly tested on Hickok 539B . Hickok 539B is a mutual conductance (Gm) type tube tester. Sylvania 6L6 vacuum tube. One tube,circa 1950s, U.S.A. made. <<<<<<< As pictured = The tube you see is the tube you get!
Thoroughly tested on Hickok 539B . Hickok 539B is a mutual conductance (Gm) type tube tester. RCA 6L6 vacuum tube. One tube,circa 1970, U.S.A. made. <<<<<<< As pictured = The tube you see is the tube you get!
Thoroughly tested on Hickok 539B . Hickok 539B is a mutual conductance (Gm) type tube tester. Sylvania 6L6 vacuum tube. One tube,circa 1940s, U.S.A. made. <<<<<<< As pictured = The tube you see is the tube you get!
Thoroughly tested on Hickok 539B . Hickok 539B is a mutual conductance (Gm) type tube tester. CBS 6L6 vacuum tube. <<<<<<< As pictured = The tube you see is the tube you get! One tube,circa +/-1950, U.S.A. made.