[Amps] Pi-L Network

[Steve Thompson]

Claude Frantz wrote:
> Peter Voelpel wrote:
> 
>> Would be very interesting.
>> And the Pi-L  IS better then the Pi on harmonic suppression.
> 
> Yes, it is better. But a little bit only. If you have a serious harmonic 
> supression problem, it will probably not be sufficient. This is the 
> reason why I think that it is not the preferable way to seek for a 
> solution in the Pi-L. If it works for you, then it's fine.

I suspect it matters a lot how you design it and what your aims are. 
Simplistically, the main function is transforming the aerial impedance 
to what the valve anode wants to see. If you do this with four elements 
instead of three, you can choose to trade off different parameters - for 
example, you can match over a wider bandwidth so you need to retune less 
often - or you can get higher harmonic suppression.

Thinking of it as a low pass filter, going from three elements to four 
I'd expect more than 6dB harmonic improvement for the same operating 
bandwidth.

Steve