Description
EL84 Matched, Lot of 4pcs Output Pentode Tubes, Old Stock, used, tested, and in good operational condition. Manufacturer – TELAM, Poland. Basic Data Filament voltage, V: 6.3 AC Filament current, mA: 760 Plate voltage, V: 250 Plate current, mA: 48 Grid 1 voltage, V: -7.3 Grid 2 voltage, V: 250 Grid 2 current, mA: 5.5 Cathode bias resistor, ohm: 135 Grid 1 resistor for fixed bias, max, kohm: 300 Grid 1 resistor for auto-bias, max, Mohm: 1.0 Transconductance Gm, mS (mA/V): 11.3 Testing and Matching The tubes were tested under fixed-bias conditions as described in the basic data: both plate and grid 2 voltages were 250V DC, and grid 1 voltage was -7.3V DC. All measurements were performed with 1% precision after the tubes had warmed up and stabilized. A regulated, high-grade tube-based power supply was used for testing. The tubes were matched in pairs as closely as possible, both by plate current (in mA) and transconductance (in mS/mA/V). Grid 2 current is approximately 5.5mA. Additionally, the tubes were tested in auto-bias mode to ensure stable performance under different working conditions. Thus, the tubes were matched into pairs as shown in the table: Stock ? set/tube ? I plate, mA Ig2, mA Gm, mS 58 1/1 47,3 5,7 10,1 59 1/2 47 5,2 10,1 60 2/1 48 5,5 10 64 2/2 49 5,6 10 Combined Shipping Available If you purchase multiple items, I offer combined shipping to help you save on costs. Please request an invoice before paying so I can adjust the shipping charges accordingly. Thank you!
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