Matched Pair Philco Type / Number 27 #27 Vacuum Tubes Valves Black Plates 2nd Quarter BW27 This National Union number 80

This National Union number 80 rectifier tube was tested on our Paul Hart-calibrated TV7/U for shorts

This hardcover book is in very good condition and comes from a non-smoking household

I do not have the ability to test them and they are being sold as-is with no returns

top D getters and anode radiators

new in box Sylvania 6SH7 tubes tested to spec on our Paul Hart-calibrated TV7/U

Matched Pair Philco Type / Number 27 #27 Vacuum Tubes Valves Black Plates 2nd Quarter BW27 This National Union number 80This matched pair of Philco Type 27 triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Transconductance measured 35 for Tube One and 36 for Tube Two where minimum (65%) is 25 and 100% is 38. The tubes have rounded black plates; wire snubbers for increased rigidity and lowered microphonics; dimpled sheet getters; excellent flashing and well secured bases and bottles that are nice and