Matched Pair RCA 6CG7 6FQ7 Vacuum Tubes With Shields NOS-Testing Type 27 By Brand It is probably a Mullard

It is probably a Mullard

Two end links are available

There were no shorts or gas and they tested as follows:

GM-Delco-BRANDED 6AX8 tubes tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair RCA 6CG7 6FQ7 Vacuum Tubes With Shields NOS-Testing Type 27 By Brand It is probably a MullardThis new old stock testing matched pair of RCA 6CG7 6FQ7 dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 73 74 while Tube Two measured 78 75 where minimum (65%) is 50 50 and 100% is 77 77. These tubes have steel support rods and top, harp shaped getters and anode radiators for cooler operation and longer tube life. There is also a shield between the triodes