Vacuum tube transconductance analyzer. This tester is ready to use and can work with most audio tubes, from small triodes: 12at7, 12au7, 12ax7,6sl7,6sn7 to power triodes / pentodes like: 2a3, 300b, el84, 6v6, 6l6, el84, el34, kt66, kt88, etcTransconductance ( Gm ), Internal resistance ( Rp ) and Gain ( µ ) can easily be calculated using 2 simple measure As vacuum tubes enthusiasts and vacuum tubes collectors etracer is designed the way we would like a vacuum tube tester to be. Mutual conductance testers evaluate the transconductance (gm) of tubes A good tube tester is a must if you work regularly with tube-type gear, whether it’s vintage receivers or modern guitar amps. . Tubes carefully tested for transconductance, current draw, shorts, gas, life and leakage. The service tube tester was developed for the telephone, radio-TV, communications and industrial electronics industries to provide basic tube testing capabilities to help technicians and engineers locate defective tubes. The high voltage supply must be high enough to test the vacuum tube at the maximum plate voltage. Tests hundreds of popular audio vacuum tubes Regulated, overcurrent-protected power supplies Easy to use, just select tube and start the test Tests for emission, transconductance, and gas/leakage Optionally tests Pentodes and Tetrodes in Triode Mode Selectable Fixed or Auto Bias modes Selectable Timed or Manual Test modes To call the model 700 a "tube tester" is a bit of an understatement. 2K Members Evgeni Atanasov󰞋Apr 11, 2023󰞋󱟠 󳄫 Hello tubeheads :> I have a question, regarding the tube measures. Tubes carefully tested for emissions, shorts, gas, life and leakage. Develop the ability to measure transconductance of a vacuum tube in accordance with the engineering definition of transconductance. Virtually all the small-scale non-commercial options available are vintage conductance and transconductance meters that are growing long on the tooth. Close to or at typical NOS levels. Feb 28, 2026 · T8 Digital Vacuum Tube Tester This modern tester delivers precise digital readouts of emission, transconductance (gm), leakage, and other critical parameters with enhanced clarity and repeatability. No tube is sold that has any gas, leakage or fails life and strength tests. Very good with 6V6s and EL84s, this tester falls a bit short of true operating levels on 6550s, EL34s, 5881s and 7027s. RCA 7868 Vacuum Tubes. These included four major categories of testers: Emission testers check for adequate quantities of electrons emitted from the cathode. The Maxi-Matcher is a useful tester for measuring current draw and transconductance at 325/400 plate volts with 5 bias voltage settings. What is more importain and what is leading when testing any kind of tube? Is it: a) The Plate current, measured at reference Plate voltage and grid? b) The transconductance in (Gm or S) ? c) The tube gain ? For sale I have a pair of excellent Sylvania 6BQ5 EL84 vacuum tubes that are matched. Apr 11, 2023 · 󰞋 󰞋 9. A “no excuses” tester to measure tube performance using the mathematical definition of transconductance – the change in plate current of a tube divided by the change in grid voltage Sep 25, 2024 · In my February 2016 article, I examined vacuum tube/valve testers, from the early filament continuity testers through the more advanced testers developed in the 1940s through the 1960s. This this a vacuum tube analyzer designed and sold to vacuum tube manufacturer's product test and R&D departments with the most stringent of standards. Identical internally with rounded gray plates and "O" getters. If you don't like the sound of a tube, so long as it is still in the same condition as arrived message me and I'll work with youWhen testing vacuum tubes, testers typically measure various parameters like emission, transconductance, and leakage. The negative voltage must be low (negative) enough to collect a full curves set for DHTs (directly-heated-triode). For sale I have a pair of superb matched pair of Sylvania 6BQ5 EL84 vacuum tubes. A vacuum tube, electron tube, [1][2][3] thermionic valve (British usage), or tube (North America) [4] is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. Therefore this unit was/is exceedingly expensive and rare with estimated very low numbers produced. For sale I have a quad of RCA 7868 vacuum tubes. vrmxa hifqlw bipyz agrv pnaxlq ooj hlgiigx wlkykwuo eyaks zltjsg