Matched Trio RCA 6FQ7 / 6CG7 Vacuum Tubes

Matched Trio RCA 6FQ7 / 6CG7 Vacuum TubesThis matched trio of RCA 6FQ7 6CG7 dual triodes was tested on our TV7 U for shorts, gas and transconductance. There were no shorts or gas and their readings are as follows: Tube One measured 66 71 while Tube Two measured 68 67. Tube Three measured 70 70 where minimum (65%) is 50 50 and 100% is 77 77. These tubes have steel support rods; ladder plates; side D getters and excellent flashing. As I write, I am playing them with adapters (not included) in

new in box milspec National Union JAN-CNU 2X2A VT-119 879 tube tested to spec on our Paul Hart-calibrated TV7/U

though they are labeled differently

gray bottles and bottom

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

The four new old stock

one is a Hytron

OEM-BRANDED black glass 6K6GT tubes was tested on our Maxi-Matcher tube tester with 325 volts on the plates and a bias of -36 volts

(New US-made 6BG6s typically test with plate current readings from the mid 20s to mid 50s with transconductance within a standard deviation of 2300 micromhos or so

Plate current draw was 19

They measured (from left to right) 51/50

where minimum (65%) is 36 and 100% is 55

Will happily test it if you can send me the settings