by Jouni Verronen, OH8RO
The other part of the program calculates the alteration in turns number needed to resonate the coil - a toroid or a one layer cylinder coil - at another frequency with another capacitor.
Calculated values can then be used in a circuit analysis program for e.g. crystal filter design. The program also has a feature, which is helpful, when one wonders if a crystal at hand is good for a particular crystal oscillator circuit at a certain frequency. One can give any frequency near series resonance, and the program calculates the reactance and corresponding capacitance/inductance values needed to resonate the crystal. Using arrow keys the frequency can be tuned.
The program was originally made to help in designing matching circuits to UHF transmitters, where the standard practice is to use series microstrips and shunt capacitors. It has a useful feature, that all the input values are tunable using arrow keys. So e.g. line length can be tuned keeping watch when parallel resistance is at the right level. Then also the capacitance value of the shunt capacitor needed can be read right on the screen.
The main program uses electrical parameters for the transmission line, but there
is under F2 a subprogram, which calculates those from mechanical parameters if
The program has also been used in teaching transmission line properties.
For clarity a Smith Chart shows complex impedances at both ends.
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