Description

1 - Western Electric 403B Tube Made in USA Black Plates D-getter See pictures and ask any questions before buying, not after Tested on enhanced Tripplett E3444 Laboratory Tester prepared by Paul Hart of Roswell Ga. Results = All will be in the 4000-5000 range Bogey(100% or New) = 5100 @ 7.7 mA +/- 10% The measurements in this listing were taken on a Triplett 3444 modified to test the tube as an amplifier in accordance with RMA/EIA specifications, utilized by all US and most foreign tube manufacturers. This tester applies test conditions for this tube as shown below (including the precise filament voltage) and then measures transconductance (gm) in accordance with the engineering definition of gm. Tubes may also be operated under the test conditions for extended periods to be sure that it is stable. A tube must be tested in this manner to compare its test results with the manufacturer’s original intent or with other tubes of the same type. Most tube testers do cannot apply the test conditions required or conduct a valid gm test. For more details on the test and our test equipment, please contact us. The test conditions for this listing are __ 180 _Volts plate, __ 180 _Volts screen, ___ 180 ___ Cathode Bias Resistor (CBR) What were your tubes tested at? I do combine S&H