[Amps] Discrepencies in Pi-net calculators

[Larry Benko]

Steve,

According to my calculations all 3 networks match 50 ohms to 135 ohms @ 
28.03MHz.  However Group 1 has a Q of 1.9, Group 2 has Q of 4.7, and 
Group 3 has Q of 2.7 according to my understanding of nodal Q.

73,
Larry, W0QE



On 11/19/2013 7:24 PM, Steve Flood wrote:
> I've been working through some Pi-network design for an input tuning network
> recently and have tried out several online calculators as well as
> traditional formulas and  common software.  Using the same input variables
> for each tool, I generated three very different results.
>
>   
>
> For Rin = 50 ohms, Rout = 135 ohms, f=28.03 MHz, Q=2.7
>
>   
>
> Group 1:  Tonne's PI-EL software, ARRL Handbook formulas, and Jim Hawkins
> online Java Radio Calculator.
>
> Cin = 93pF, L=457nH, Cout=79pF
>
>   
>
> Group 2:  VK1OD online calculator, electronicdesign.com calculator, and
> raltron.com calculator.
>
> Cin = 307pF, L=251nH, Cout=194pF
>
>   
>
> Group 3:  EEweb.com calculator, VK2ZAY online calculator, and Impedance
> Matching Network Designer online calculator (sandiego.edu).
>
> Cin=163pF, L=383nH, Cout=113pF
>
>   
>
> So then, you can see my dilemma here.   Why are these so different? And why
> the common groupings?
>
>   
>
> Steve, KK7UV
>
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