Matched Pair RCA Clear Top 12HG7 12BY7 Vacuum Tubes NOS-Testing October 13 2024 new in box Zenith 17AY3

new in box Zenith 17AY3 / 17AY3A / 17BS3 / 17BS3A tubes tested to spec on our Paul Hart-calibrated TV7/U

The spine is in fine shape with no loose pages and there is a rip in the cover towards the top

36/12 and 37/13

It has black plates

Matched Pair RCA Clear Top 12HG7 12BY7 Vacuum Tubes NOS-Testing October 13 2024 new in box Zenith 17AY3This 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 80 while Tube Two measured 82 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.