4 RCA Cunningham Number / Type 41 #41 Vacuum Tubes Valves Engraved / Hot-Stamped Bases Lot Of Four

4 RCA Cunningham Number / Type 41 #41 Vacuum Tubes Valves Engraved / Hot-Stamped Bases Lot Of FourThese four RCA Cunningham engraved hot stamped base type number 41 tubes tested as follows on our Paul Hart calibrated TV7 U: 45, 52, 56 and 62 where minimum (65%) is 40 and 100% is 62. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY SISTER SITE "LOWTECHTWOO" AND OR CALL OR TEXT US AT 202 372 6931 IF YOU DO NOT SEE WHAT YOU NEED OR HAVE ANY QUESTIONS. 1. MOST FORMS OF SHIPPING EXCEPT MEDIA MAIL

crenelated mica spacers

new in box US-made 12BR7 tubes tested to spec on our Paul Hart-calibrated TV7/U

This pair of NOS-TESTING RCA 6BG6G output tubes was tested on our Maxi-Matcher with 400 volts on the plates and a bias of -48 volts for shorts

These four US-made 6AB4 tubes tested to spec on our Paul Hart-calibrated TV7/U

This matched pair of RCA black plate triple mica 6CL6 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

Tube One drew 26

balanced sections

This matched pair of Sylvania black plate 12BY7 / 12BY7A tubes was tested on our Paul Hart-calibrated TV7/U for shorts

These tubes have copious bottom flashing

They tested (from left to right) as follows: 52 and 55 where minimum (65%) is 40 and 100% is 62

Transconductance: 1410 / 1411 (New is approximately 1450)

They are lightly microphonic and not suitable for environments with excessive vibration