>How does the problem manifest itself, Rich.
Input SWR not good enough to prevent throttle-back..
>I have used the
>Alpha 78 quite a bit with a Kenwood TS-940, Ten-Tec
>Paragon, and Kenwood TS-950SDX. All of these rigs are
>solid state, but don't seem to have any trouble driving the
>Alpha 78.
>
>BTW, the Paragon uses relay switched low-pass filters (5
>pole I believe) to filter the output of their PA.
These are usually band-pass filters.
>I suspect
>Kenwood does similarly. These filters may be providing
>the needed energy storage to average out the non-linear
>impedance presented by the unfiltered cathode input on the
>Alpha 78.
>
If there is no tuner in the radio, yes.
cheers, Mike
>>> Amplifiers such as the MLA-2500, SB-230, 374, 78, and 76PA have no tuned
>>> input. This is not a problem when such a g-g amplifier is driven by a
>>> tube-output radio such as the TS-830S. The reason is that although the
>>> input Z of a cathode-driven triode fluctuates from roughly 1/3 of the
>>> average driving Z on negative peaks to a virtual open circuit on positive
>>> peaks, the Pi-network tuned circuit in a tube-output radio acts as a
>>> flywheel to smooth out the Z fluctuation at the cathode/s.
>
>
>
>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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