Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Valves Triple 3 Mica Black Plates

Matched Pair Sylvania 6BL7 6BL7GTA Vacuum Tubes Valves Triple 3 Mica Black PlatesThis matched pair of Sylvania 6BL7GT dual triodes was tested on our TV7 U for shorts, gas and transconductance. There were no shorts or gas. Tube One measured 47 44 while Tube Two measured 48 43 where minimum (65%) is 25 25 and 100% is 38. 5 38. 5. These tubes have copper support rods; beefy black plates: three mica spacers for improved mechanical stability and low microphonics; top D getters and anode radiators for cooler operation and extended life.

The pressing is quite good with a few pops and crackles and I would give it a 7-7

new in box Sylvania 6BQ6GTB tubes tested to spec on our Paul Hart-calibrated TV7/U

EIA Factory Codes: none

Transconductance measured 2340 micromhos with a plate current draw of 24

There is a crack in the base

This is a new old stock

short base

anode radiators for cooler operation and longer tube life

This milspec Sylvania type 80 JAN-CHS-80 VT-90 rectifier tube was tested on our Paul Hart-calibrated TV7/U

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 end links appear to be made of stainless steel and rose gold or copper

Etsy will indicate how many remain in this Dutch auction