Matched Pair General Electric GE 12BH7 12BH7A Vacuum Tubes 12AU7 Substitute For Tube Rolling NOS-Testing

Matched Pair General Electric GE 12BH7 12BH7A Vacuum Tubes 12AU7 Substitute For Tube Rolling NOS-TestingThis new old stock testing matched pair of GE 12BH7A dual triodes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 65 69 while Tube Two measured 66 70 where minimum (65%) is 30 30 and 100% is 46 46. These tubes have gray plates; copper support rods; excellent flashing; top harp lyre getters and anode radiators for improved cooling and longer tube life. I have played them

This matched pair of OTK-MANUFACTURED black glass 6V6GT output tubes was tested on our Maxi-Matcher 2 for shorts

perfectly-matched pair of RCA 5879 tubes was tested on our Paul Hart-calibrated TV7

It has a micanol base

Transconductance measured 59 for both tubes where minimum (65%) is 40

new in box RCA 14Q7 tubes tested to spec in our Jackson 648 Mutual Conductance tester

This GE 12BE6 tube -- and another just like it -- tested to spec on our Paul Hart-calibrated TV7/U

This lot of three US-made Type 27 / 227 triodes were tested on our Paul Hart-calibrated TV7/U for shorts

a flared base

It measured 45/42 where minimum (65%) is 40/40 and 100% is 62/62

Flashing Quality: good

They measured 96/80 for Tube One and 98/80 for Tube Two

I find this book very accurate -- especially considering when it was written