• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

805A and 805

The 805 and 805A are internally similar except the Anode, in an 805A, connects to pin 3, not the top cap.
Nice little transmitter valves. Used many years ago in telephony work by various telephone companies.
The 805 has 10volt heaters at3.25Amps and is the predecessor of the 813.

Hope that helps. Attached is a photo;


  • Screenshot 2023-06-04 at 08.46.57.png
    Screenshot 2023-06-04 at 08.46.57.png
    345.8 KB · Views: 72
Hello ,I had newly acquired, I was also thinking about the 805 with the plate cap, there is a hole for the HV on the chassis on each side, probably for connecting to the anode plate using a cable which connector (?) which is not supplied.
any idea?


  • 20230826_164407.jpg
    318 KB · Views: 57
  • 20230826_164544.jpg
    235.8 KB · Views: 67