R. Measures wrote:
** The grid does not and can not draw current when a competent
operator sets the grid potential just above the level where it can draw
grid-current with the max PEP drive that's available.
That is only true if the grid input circuit is guaranteed to be able to
soak up all possible levels of drive without allowing grid current...
but that also has disadvantages: either the exciter runs flat-out and
generates unnecessary IMD of its own, or else the exciter runs at a
lower level and the amplifier is seriously under-driven.
I truly cannot see why anyone should design (or defend) a high-impedance
bias supply whose voltage regulation will collapse at the first trace of
either normal or negative grid current. What's the point, when a
better-regulated supply is just as easy?
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
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