OUR INSTRUMENTS ARE CALIBRATED WITH REFERENCE TUBES AND POWERED WITH UPS LINE VOLTAGE FOR A MORE ACCURATE AND STABLE MATCHING PROCESSFor English Language see below 11626 ( VT-137 ) RCA NOS Radiotron Power Triode for Darling-Amp Matched PairMADE IN USA Testate con AVO VCM 163 Tube tester:I nostri strumenti sono calibrati con tubi di riferimento.Vf = 12,5V; Va = 250V; Vg = -32V Media 100% Gm = 2,1 ; Ia = 20 mARISULTATO DEL TEST: MOLTO FORTE Valvola 1:Gm = 2,2 ; Ia = 22 mAValvola 2:Gm = 2,3 ; Ia = 24 mA??Ulteriori test eseguiti:Test MicrofoniaQualità dellEmissioneTest per CortocircuitiTest per GAS Spedizione con imballo protetto per una maggiore sicurezza.Imballaggio in carta riciclata e riciclabile. Nastro adesivo di chiusura in carta marrone - ECO-KRAFTEco compatibile - SOLVENT FREE 1626 ( VT-137 ) RCA NOS Radiotron Power Triode for Darling-Amp Matched PairMADE IN USA Tested with AVO VCM 163 Tube tester:Our instruments are calibrated with reference tubes.Vf = 12,5V; Va = 250V; Vg = -32V AVERAGE 100% Gm = 2,1 ; Ia = 20 mATEST RESULTS: VERY STRONG Tube 1:Gm = 2,2 ; Ia = 22 mATube 2:Gm = 2,3 ; Ia = 24 mA?Other test made:Test for MicrophonicsTest for Emission QualityTest for ShortsTest for GAS Shipping with protected packaging for best security.Our Packaging is in recycled and recyclable paper. Brown paper sealing tape - ECO-KRAFTEco friendly - SOLVENT FREE