Matched Pair RCA Clear Top 12HG7 12BY7 Vacuum Tubes NOS-Testing LP SW 3386 new in box US-made 4CB6

new in box US-made 4CB6 tubes tested to spec on our Paul Hart-calibrated TV7/U

This Western Electric 347A will be tested on our Paul Hart-calibrated TV7/U for shorts

There is no mounting hardware or coax

Transconductance measured 3900/4500 micromhos

Tube One measured 73/75 while Tube Two measured 75/76 where minimum (65%) is 56/56 and 100% is 87/87

Matched Pair RCA Clear Top 12HG7 12BY7 Vacuum Tubes NOS-Testing LP SW 3386 new in box US-made 4CB6This new old stock testing matched pair of RCA clear top 12HG7 tubes was tested on our Paul Hart calibrated TV7 U (on the 12BY7 setting) for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 74 while Tube Two measured 78 where minimum (65%) is 46 and 100% is 71. These tubes have anode radiators for cooler operation and longer tube life; side O getters and excellent flashing. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES.