All tubes test good on a TV-10D/U military tester. No shorts; all pass tests for gas & leakage. Minimum mutual conductance for both triode sections is 1400 micromhos; average conductance for a new tube is 2200. Test results in micromhos for each tube as shown in the photo from left to right are:
Raytheon: T1 = 2000, T2 = 1800
Raytheon: T1 = 2000, T2 = 1800 - ID # worn. Tube made in Japan - all other tubes made in USA.
Sylvania: T1 = 2600, T2 = 1950 - Logo very faint.
Rad-Tel: T1 = 2400, T2 = 2500
Admiral: T1 = 1800, T2 = 2150 - 12AU7 tube; no "A" suffix. All other tubes are 12AU7A.
Sylvania: T1 = 2300, T2 = 2000
Sylvania: T1 = 1700, T2 = 2200
Sylvania: T1 = 2100, T2 = 2300
Sylvania: T1 = 2400, T2 = 2350
Zenith: T1 = 2200, T2 = 2250
The lettering is worn on these but the tube numbers are readable except as noted above. Each tube has it's test results written on a blank spot on the side with a felt tip pen. This is easily removed with a Q-tip and some Windex or alcohol.
Tubes have been sold. $30 for all. First Class USA shipping is included. PayPal only please.
Raytheon: T1 = 2000, T2 = 1800
Raytheon: T1 = 2000, T2 = 1800 - ID # worn. Tube made in Japan - all other tubes made in USA.
Sylvania: T1 = 2600, T2 = 1950 - Logo very faint.
Rad-Tel: T1 = 2400, T2 = 2500
Admiral: T1 = 1800, T2 = 2150 - 12AU7 tube; no "A" suffix. All other tubes are 12AU7A.
Sylvania: T1 = 2300, T2 = 2000
Sylvania: T1 = 1700, T2 = 2200
Sylvania: T1 = 2100, T2 = 2300
Sylvania: T1 = 2400, T2 = 2350
Zenith: T1 = 2200, T2 = 2250
The lettering is worn on these but the tube numbers are readable except as noted above. Each tube has it's test results written on a blank spot on the side with a felt tip pen. This is easily removed with a Q-tip and some Windex or alcohol.
Tubes have been sold. $30 for all. First Class USA shipping is included. PayPal only please.
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