[Amps] Discrepencies in Pi-net calculators

[Steve Flood]

>>Larry wrote:

>>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.

 

I used the same variable values for each tool, including a specified Q.  I
was hoping to generate some discussion in the group as to how the results
fall into three distinct groupings, rather than asking for help in designing
a specific network.

 

I've added a few more tools to the groupings:

 

Group 1

Tonne's PI-EL software

ARRL Handbook formulas

Jim Hawkins online Java Radio Calculator

G3SEK spreadsheet

Leonard Anderson's article ""Pi Network Design" in the March, 1978 issue of
Ham Radio.

(BTW, I found a print error in one of the formulas in that article).

 

Group 2

EIMAC "Care and Feeding..." p. 52-55

VK1OD online calculator (derived from EIMAC)

Bill Orr 23rd Radio Handbook p14-18

electronicdesign.com calculator

raltron.com calculator.

 

Group 3

EEweb.com calculator

VK2ZAY online calculator

Impedance Matching Network Designer online calculator (sandiego.edu).

 

 

Steve, KK7UV