RCA Cunningham Number / Type 85 #85 Engraved / Stamped Base Vacuum Tube Valve NOS-Testing Handel May 18 2020 They were dead quiet when

They were dead quiet when the preamp was muted and had excellent frequency response

new in box Sylvania 1X2 tubes tested to spec on our Paul Hart-calibrated TV7/U

This hardcover book is in fair condition

respectively where new/nominal is within one standard deviation of 5000

RCA Cunningham Number / Type 85 #85 Engraved / Stamped Base Vacuum Tube Valve NOS-Testing Handel May 18 2020 They were dead quiet whenThis new old stock testing RCA Cunningham engraved base type 85 tube was tested on our Paul Hart calibrated TV7 U for shorts, gas, emissions and transconductance. There were no shorts or gas. It measured 45 in its triode section where minimum (65%) is 25 and 100% is 39. The diodes measured 56 and 56, respectively, where minimum (65%) is 40 40 and 100% is 61 61. IN 2021 WE PURCHASED 150,000 VACUUM TUBES. IF IT'S NOT LISTED, WE PROBABLY HAVE IT. PLEASE