RCA Cunningham 5Z3 Vacuum Tube Black Plate Rectifier Shoulder ST Shape 3CZ3A Octal 6 milliamps/2150 micromhos and 18

6 milliamps/2150 micromhos and 18

This GE 35Z5GT tube tested 55 our Paul Hart-calibrated TV7/U where minimum (65%) is 40 and 100% is 62

new in box Sylvania 1291 industrial-quality tubes tested to spec on our Paul Hart-calibrated TV7/U

This matched trio of GE 12HG7 tubes was tested on our Paul Hart-calibrated TV7/U (on the 12BY7 setting) for shorts

RCA Cunningham 5Z3 Vacuum Tube Black Plate Rectifier Shoulder ST Shape 3CZ3A Octal 6 milliamps/2150 micromhos and 18This RCA Cunningham 5Z3 rectifier tube was tested on our Paul Hart calibrated TV7 U for shorts, gas and emissions. It tested 68 in Section One and 58 in Section Two where minimum (65%) is 40 40 and 100% is 62 62. It has a tall, engraved stamped base; black plates, copious amounts of flashing and a nice, old fashioned shoulder bottle. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE