Matched Pair RCA 6GU7 Vacuum Tubes NOS NIB RCA OSC These four Ken-Rad tubes tested

These four Ken-Rad tubes tested as follows on our Paul Hart-calibrated TV7/U:

They measured 23

They have DC and BD date codes

This lot of three US-made type 42 tubes was tested our Paul Hart-calibrated TV7/U for shorts

100% is 56/56

Matched Pair RCA 6GU7 Vacuum Tubes NOS NIB RCA OSC These four Ken-Rad tubes testedThis new old stock, new in box matched pair of RCA 6GU7 dual triodes was tested on our Jackson 648 Mutual Conductance tester for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 95% 100% for Tube One and 95% 105% for Tube Two. (New 6GU7s typically test from within a half standard deviation of 2000 micromhos and the Jackson expresses this in terms of a percentage.) I have played it in my Alan Eaton single ended