[Amps] Pi-L In-circuit Adjustment Question

[TexasRF@aol.com]

Hi Mike, in answer to cold tuning the output network:
The tube contributes a significant part of the total C1 value; for this  
reason, it needs to be in the circuit. If this causes a problem connecting your  
load resistor, the resistor can be placed across the rf choke with nearly the  
same results, especially on the bands between 160 and 20m, 
 
C1 resonates the network and C2 adjusts the output impedance. Therefore, in  
your cold test C2 should be used to provide 50 ohms output. C1 resonates the  
network and you should be able to remove or null the reactance reading showing 
 on your bridge. There is some interaction between C1 and C2 but the  network 
should act as described. Said another way, C1 will also change the  50 ohm 
reading but not as much as C2, C2 will change the resonance/reactance but  not 
as much as C1
 
The method you are using is a wise move to confirm all is as expected. I  
have used this method as high as 432 MHz with good results.
 
Happy tuning!
 
73,
Gerald K5GW