Re: [Amps] Re: matching network

["Ian White, G3SEK" <G3SEK@ifwtech.co.uk>]

R. Measures wrote:
> > R. Measures wrote:
> > > > > **  Ian --  How does one convert this figure into a determination of
> > > > > how grid current divides between the grid and the screen during g-g
> > > > > operation?
> > > >
> > > >
> > > > Sorry, maybe what I said was misleading - I'm not sure if it's possible
> > > > to calculate Ig1/Ig2 in cathode-driven operation directly from mu-g1g2.
> > > >
> > > > They both result from the tube's internal tube construction, however,
> > > > which is why I believe that if one is high, the other will be too.
> > > **  So if a tetrode with a g-/g2 amplification of 4 to 5 has c. 25% of
> > > total grid current flowing in the screen, a tube with a g/g2
> > > amplification of 13 might have c. 8% of the total grid-current flowing in
> > > the screen?
> >
> > Couldn't say... you'd have to do a point-by-point analysis using the
> > characteristic curves.
> **  Ian --  The sticky wicket is that there are no characteristic curves
> for 0V on the  screen.

No *published* characteristic curves, for sure.

The manufacturers only publish characteristic curves for operating 
conditions that they can recommend. Outside of those recommendations, 
we're on our own.


--
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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