[Amps] Plate Load Calc.

[Tom W8JI]

> For calculating Resonant Plate Load, Orr's Handbook 
> suggests 1.8 for the K-factor for Class B and C.
> Tonne's PI-EL software uses a K-factor of 1.8 for Class B 
> and 2.0 for Class C.
> This gives quite a difference in the Resonant Plate Load. 
> Let me guess...the answer is "both are correct".

K is a rough approximation. As a matter of fact the Q you 
calculate using Rp/Xcp in a pi-net is another approximation. 
The actual network Q is higher.

Fortunately the tank performance and system efficiency 
doesn't change radically as Q is varied from the very 
minimum of just over the square root of anode operating 
impedance over load impedance to a few times that value. 
Hams go overboard calculating and trying to use exact tank 
values using formulas that are just rough approximations.

Is K 1.8 or 2? Why worry? It might actually be 1.5 or 2.5. 
If you get the Q too low the loading control will work 
backwards. If you get it too high the tuning will be 
needlessly sharp and there will be a little more tank heat.

73 Tom