Strange power level change!

Discussion in 'Amateur Radio Amplifiers' started by WA6MHZ, May 1, 2012.

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  1. WA6MHZ

    WA6MHZ Premium Subscriber

    When I tune up my Drake L7, I see the power slowly increase, almost like a capacitive action. I see it on the scope too. When I key down with a carrier, it will start at a low value and then rise to the correct output.

    What could cause that?
     
  2. AF6LJ

    AF6LJ Ham Member

    Does it do it on all bands???

    What's going on with the plate current / voltage and the Grid current?
    Input VSWR; does it change??
     
  3. WA6MHZ

    WA6MHZ Premium Subscriber

    Plate meter doesn't work. Does it on all bands
     
  4. AF6LJ

    AF6LJ Ham Member

    What about your input VSWR?
    Does it change as the amplifier is coming up to power?

    The most obvious thing I would look at right off would be the antenna relay.
     
  5. AF6LJ

    AF6LJ Ham Member

    Let us know what you find Pat.
     
  6. WA6MHZ

    WA6MHZ Premium Subscriber

    I notice it doesn't seem to happen on a Dummy load!
     
  7. K0BG

    K0BG Platinum Subscriber

    Well, that's telltale isn't it? What is the antenna?
     
  8. AF6LJ

    AF6LJ Ham Member

    Now the problem is simple to find.
    At least isn't in the amplifier.
     
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