Matched Pair General Electric GE 6C4 6C4WA Vacuum Tubes Milspec NOS NIB Zenith Drawer It has very-light surface noise

It has very-light surface noise

Tube One measured 1630 micromhos

an O-getter

1 milliamps while it measured 2380 micromhos where new US-made 6L6s typically test with plate current from the low 20s to mid 30s and with transconductance from 2200 micromhos or so

I wish I could tell you how they sound and from what I can suss out

Matched Pair General Electric GE 6C4 6C4WA Vacuum Tubes Milspec NOS NIB Zenith Drawer It has very-light surface noiseThis perfectly matched pair of milspec GE 6C4 6C4WA triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Both tubes measured 72 where minimum (65%) is 55 and 100% 85. They have gray plates; top O getters and two additional support rods for increased ruggedness and microphony suppression. These tubes have acid etched codes and designations as well as silk screened 68 26 188 5 67 50