[Amps] SB-220 bias question

[Gudguyham at aol.com]

In a message dated 8/29/2009 5:49:01 P.M. Pacific Daylight Time,  
lists at subich.com writes:

> but  the AAL-80, AL-82 et al. do not change the plate 
> voltage on  any mode.  The operator is told to adjust 
> power output  according to the mode.  

Reducing the power output without  changing the plate voltage 
will result in a miss-tuned condition.  If  the pi-network is 
tuned for full output and the drive reduced (power  adjusted). 
If the output is retuned and the lower drive level, the plate  
load impedance will be incorrect for the design of the pi- 
network and  the pi-network will need to be detuned (run at 
a higher Q).    

Fine, but none of those amps change the plate voltage in the different  
modes, so you mean to tell me they are designed wrong?