>I have been working on a tetrode amp which was slow to generate power
>and varying
>input swr and signs of negative grid current.
>
> Last nite, I removed all input circuit components and then started
>over. The first component reinstalled was the 50 ohm input resistor. I
>was working with no voltages applied and continued building the circuit
>one component at a time. Everyting was stable. I changed the value of
>the coupling/dc blocking capacitor to a 1200pf mica.
>The circuit now consists of first feeding the resistor, then coupling
>the resisual voltage to the grid. The negative bias is fed directly to
>the grid via a 50uh inductor. All is well.
>
> As far as the original problem? I really cant say, except I suspect
>the coupling/blocking capacitor was the culprit...
>
> I still have to bypass the meters, but the operation is now stable.
>
> Thanks to all who have helped with their input.
>
Thanks for the good news, Lynn.
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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