Callsign
ad: NI4L-1
Results 1 to 3 of 3

Thread: GI7B

ad: L-HROutlet
ad: l-assoc
ad: l-innov
ad: l-tentec
ad: l-Waters
ad: l-WarrenG
ad: l-gcopper
ad: l-rl
ad: l-sarc
  1. #1

    Default GI7B

    Hello everyone.
    I want to ask what is the maximum output power from a GI7B triode and at what anode current in the following cases:
    HF, 1KV
    HF, 2KV
    VHF, 1KV
    VHF, 2KV

    because I plan to make a supply and for me it's more easier(and cheaper) to make for 1-1.2 KV.

  2. #2

    Default

    You can easily calulate this by guestimating 60% efficiency and using the triode's 350 watt plate dissipation rating. I'd do it for you but I'm posting this reply from a cell phone.

  3. #3
    Join Date
    Oct 2003
    Location
    Middle Georgia USA
    Posts
    7,722

    Default

    Quote Originally Posted by YO9ICT View Post
    Hello everyone.
    I want to ask what is the maximum output power from a GI7B triode and at what anode current in the following cases:
    HF, 1KV
    HF, 2KV
    VHF, 1KV
    VHF, 2KV

    because I plan to make a supply and for me it's more easier(and cheaper) to make for 1-1.2 KV.

    I looked at the characteristic curves for the GI7B for you, and the plate current knees over at about 700-800 volts. This means you would compromise linearity and efficiency greatly with an anode voltage of 1000 volts or so.

    It would NOT be a good idea to start at 1000 volts.

    I have not done (and will NOT do) a Chaffe analysis for that tube, but it looks like linearity and efficiency will not be acceptable unless you have at least 2000 volts.

    At 2000 volts a rough look tells me it would be around 50% plate efficiency. Maybe a little more. That means about 300 watts output CCS and maybe 400-500 ICAS if you tolerate reduce IM performance.

    It looks like to me you would want to be at 2500 volts or higher for best efficiency and IM performance.

    I'm basing this on other tubes I have worked with that have similar characteristic curves. With lower high voltage, it will have lower efficiency and much poorer the IM performance.

    73 Tom

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •