Hi Steve
I am using fomula:
Xc1 = Zi/Q
Xc2 = Zo x rt(Zi/Zo / (Q^2 + 1 - Zi/Zo))
XL = (QZi + (ZiZo/Xc2))/(Q^2+1)
and with Zi = 50, Zo = 135, f = 28.03 and Q = 2.7
one can obtain
C1 = 306.6 pF
C2 = 194.5 pF
L = 250.9 nH
VK1OD online calculator must be using this scheme.
de Han JE1BMJ
----- Original Message -----
From: "Steve Flood" <kk7uv@bresnan.net>
To: <amps@contesting.com>
Sent: Wednesday, November 20, 2013 11:24 AM
Subject: [Amps] Discrepencies in Pi-net calculators
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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