[Amps] Re: matching network

[R.Measures]

>On 27 Jan 2004 at 19:27, R.Measures wrote:
>
>< snip >
>
>> >Both grids need to be grounded to RF... but they don't *have* to be
>> >both connected directly to chassis.
>> 
>> **  which means?
>
>I'm pretty sure Ian means that both grids need to be bypassed to 
>ground, if you're going to drive the cathode.  
>
>But I think Rich and Ian (and I) agree that doing a "grounded-grid" 
>amplifier using one of these tetrodes is a rather silly way to build 
>the amp, especially if it requires conversion from a grid-driven 
>configuration! 

**  Good point, George.  Not only would the conversion be extensive, the 
2mA limit on control-grid current would seem to suggest that a 4cx350 
could not be driven to 100% of it's emissive capability in g-g operation 
without exceeding the 2mA limit  .  

>.   Use normal operating voltages on the screen (bypassed 
>to ground) and on the control grid (fed through an RFC) and drive the 
>control grid with a suitable non-inductive resistor as a non-reactive 
>load for the exciter.  Published examples abound!

**  And, if one end of the grid-terminating R is connected directly to 
the grid, and the other end  is bypassed to chassis-gnd, the grid-bias 
supply may be connected directly to the cold-end of said R.   
>...