1. After 1976, the plate voltages were lowered slightly for improved reliability. 2. I doubt that it used a very high plate voltage . 3. Areas with 220 240 volt AC supplies could develop higher plate voltage with a simple rectifier. 4. Like most A . F . amplifiers in radios, the plate voltage is usually less than 60 volts. 5. Some tube will provide some amplification down to 22 volts of plate voltage , though the amplification may be low. 6. A tube with an unusually high level of internal gas may exhibit a visible blue glow when plate voltage is applied. 7. When a tetrode or pentode is used, the screen grid voltage is usually about one-half the plate voltage . 8. The "'866 "'is a filament preheated for at least 30 seconds before applying the plate voltage . 9. This is grounded at the operating frequency, but carries a DC potential, normally 10 to 50 % of the plate voltage . 10. Tube caps were also used for the plate ( anode ) connection, particularly in transmitting tubes and tubes using a very high plate voltage .
Mobile