Matched Pair RCA 12SL7 12SL7GT Vacuum Tubes Valves Mosaique Une Enfance They tested as follows: 60

They tested as follows: 60

This hardcover book is in fair condition

Plates: black ladder plate

copiously-illustrated book is in excellent condition

Matched Pair RCA 12SL7 12SL7GT Vacuum Tubes Valves Mosaique Une Enfance They tested as follows: 60This matched pair of RCA 12SL7GT dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 41 49 for Tube One and 44 44 for Tube Two where minimum (65%) is 32 32 and 100% is 49 49. These tubes have excellent flashing; dark, gray plates and bottom, dimpled sheet getters. Both tubes were made in the same factory just as RCA bought out Cunningham. They are