Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves Black Plates Copper Support Rods NOS-Testing ECF80 T28

Matched Pair General Electric GE 12B4 12B4A Vacuum Tubes Valves Black Plates Copper Support Rods NOS-Testing ECF80 T28This new old stock testing matched pair of GE 12B4A tubes was tested on our Paul Hart calibrated TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 44 while Tube Two measured 48 where minimum (65%) is 32 and 100% is 49. Wish I could tell you how they sound, but I don't have any equipment that uses these. WE HAVE SCORES OF THOUSANDS OF VACUUM TUBES. IF IT'S NOT LISTED, WE MAY HAVE IT. PLEASE ALSO SEE OUT ETSY

This lot of five RCA new old stock

1 % CHANCE THIS MIGHT HAPPEN

These two Arcturus gray bottle type / number 41 tubes tested as follows on our Paul Hart-calibrated TV7/U:

ETSY MAY REIMBURSE YOU EVEN IF IT WAS STOLEN

They tested as follows: 55

new in box US-made 6CY5 tubes tested to spec on our Paul Hart-calibrated TV7/U

it has excellent flashing

They tested 51/52

There was some rumble on Side Four that I found annoying

This trio of Toshiba output tubes was tested on our Maxi-Matcher in Real World Conditions with 400 volts on the plates and a bias of -36 volts for shorts

These four milspec RCA large logo 12SG7 / VT-209 tubes were tested on our Paul Hart-calibrated TV7/U for shorts

had excellent frequency response and was very quiet