Matched Pair Sylvania 7C5 Vacuum Tubes Gray Glass 6P14 new in box RCA 7A8

new in box RCA 7A8 tube tested to spec on our Paul Hart-calibrated TV7/U

new in box US-made 6KU8 tubes tested to spec on our Paul Hart-calibrated TV7/U

The default setting is one

These five GE 6SF7 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

steel support rods and outstanding flashing

Matched Pair Sylvania 7C5 Vacuum Tubes Gray Glass 6P14 new in box RCA 7A8This matched pair of Sylvania gray glass 7C5 tubes was tested on our Maxi Matcher 2 with 400 volts on the plates and a bias of 36 volt for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 2340 micromhos with a plate current draw of 24. 5 milliamps for Tube One and 2070 25. 2 for Tube Two. (New US made 7C5s typically test with plate current from the mid teens to mid 30s with transconductance from 2300 micromhos