RCA 12AT7WA ECC81 Vacuum Tube Milspec Black Plate NOS-Testing For Your Univalve Geprueft S15 46 and 50 where minimum

46 and 50 where minimum (65%) is 30 and 100% is 47

Transconductance measured 3900/4500 micromhos

RCA-BRANDED 6GB5 tube tested to spec on our Paul Hart-calibrated TV7/U

THE PRODUCT DEVELOPMENT AND IMPROVEMENT CYCLE IS OVER

Etsy will indicate how many are available in this Dutch Auction

RCA 12AT7WA ECC81 Vacuum Tube Milspec Black Plate NOS-Testing For Your Univalve Geprueft S15 46 and 50 where minimumThis new old stock testing milspec, black plate 12AT7WA ECC81 dual triode was tested on my Hickok 600A for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 3900 4500 micromhos. (New 12AT7s ECC81 typically test within 1. 5 standard deviations of 4000 micromhos). It sounded balanced, had excellent frequency response and was very quiet in my Bottlehead, though this headphone amp is not optimized for this tube type.