used but test strong/new GE RCA 6SJ7 metal tubes, from early 1950s Hickok tested

Date codes: 4-26 (26th week of 1954) & 3-52 (52nd week of 1953)

Tested on a Hickok 539B tube tester for mutual conductance

Tested at 2000 & 1775 uM micromhos mutual conductance, where 1040 uM micromhos mutual conductance is the minimum acceptable Gm value and 1900 uM micrmhos is the typical 'new' test value.

Please note the 539B tube tester is analog, so the test values may differ slightly from tester to tester.

Values are added as a means to show the tubes indeed test excellent, not an exact science. Your results can/may vary, but tubes are indeed good and strong.