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7B4 Vacuum Tube New and Used

- Description
- Specifications
The 7B4 is a high-mu single triode vacuum tube designed for voltage amplifier stages in radio receivers and audio equipment. Electrically equivalent to the 6F5 octal tube, it features a 6.3V filament rating and an 8-pin lock-in (loctal) base in a glass envelope construction. Manufactured by companies including Sylvania, Philco, RCA, and GE, this tube was widely utilized by Philco and Zenith in mid-century radio chassis. It provides high voltage gain in resistance-coupled audio driver circuits and preamplifier stages.
Tube Type: High-Mu Single Triode
Base Type: Loctal / Lock-In (8-pin)
Envelope Style: Glass T-9
Filament Voltage: 6.3 V AC/DC
Filament Current: 0.3 A (300 mA)
Maximum Plate Voltage: 300 V
Plate Dissipation: 1.0 W
Amplification Factor (µ): 100
Transconductance: 1.5 mA/V (1,500 µmhos)
Primary Function: Resistance-coupled audio voltage amplifier or preamplifier stage
Condition Options: New Old Stock (NOS) or Tested Used