6 RCA 6K6 6K6GT Vacuum Tubes Valves Gray Glass Lot Of Six 12K8 Octal new in box Philco 25Z5

new in box Philco 25Z5 tubes tested to spec on our Paul Hart-calibrated TV7/U

This matched pair of RCA steel plate 6AK5 tubes was tested on our Paul Hart-calibrated TV7/U tester for shorts

Two have MISSING CENTERING PINS

where minimum (65%) is 46/40 and 100% is 85/62

Transconductance measured 58 for Tube One and 58 for Tube Two where minimum (65%) is 40

6 RCA 6K6 6K6GT Vacuum Tubes Valves Gray Glass Lot Of Six 12K8 Octal new in box Philco 25Z5This lot of six RCA gray glass 6K6GT tubes were tested on our Maxi Matcher 2 with 325 volts on the plates and a bias of 36 volts for shorts, gas, plate current and transconductance. There were no shorts or gas and they measured as follows (from left to right, top to bottom): Tube One: 17. 1 milliamps' plate current 1220 micromhos; Tube Two: 19. 6 1810; Tube Three: 20. 9 1440; Tube Four: 23. 6 1720; Tube Five: 25. 2 1410 and Tube Six: 31. 6 1890. New