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The Windows ® program for
designing and analyzing PI and PI-L
transmitter output networks



Current revision is 2.17; revision history is at the bottom of this page


This program is designed to facilitate the design and also analysis of PI and PI-L networks as used in transmitter output circuits.

  • The design screen accepts inputs for the operating frequency, the load as seen by the final amplifier tube, the intermediate impedance (if the L-network is to be used), the output load value and the Q value for the PI-network.

  • The above values have defaults for program startup. After using the program, your current values are saved for easy program restart.

  • In addition to simply entering values into the text boxes, "tuning" buttons allow tuning the intermediate impedance up or down in 1% steps and immediately seeing the new component values on the schematic.

  • The Q value for the PI network is entered and tuned in that same manner.

  • Regardless of whether an "out of bounds" value is entered via a textbox or by tuning, the program examines the values and limits them to values which are acceptable.

  • Click on the Plot button and see transmission and return plotted. On the plot are indicated the responses for the fundamental, the second and third harmonics. Those items are also shown in tabular form at the bottom of the screen.

  • After the design has progressed to a particular point you may click on Save to save the plot. Later you may recall that plot by clicking on the Get button.

  • Design methods using tables are now history.




Here are screen dumps from the program. Click on these images to see the larger versions; use your brower's BACK button to return.

Design screen:
Design screen
Load Help screen:
Load Help screen
Inductor Design screen:
Inductor Design screen
Plot screen:
Plot screen



Updated to 2.17 - Interface and cosmetic upgrades; allow entry of value of generator output impedance (seen looking back into generator) for analysis

Updated to 2.16 - Conditional plotting error (Rmid=Rload) found and fixed; minor interface upgrades

Updated to 2.15 - Graphics revised

Updated to 2.14 - Near-total rewrite of Design screen to include a reduced-size plot on that same page

Updated to 2.13 - Significant upgrade to Design and Help screens

Updated to 2.12 - Minor changes to a page label and the last-session file

Updated to 2.11 - Improved minimum-Q error trapping

Updated to 2.10 - Added piracy notice to program opening screen

Updated to 2.09 - Deleted generic Spice netlist writer, added LTspice schematic writer
Note: Tonne Software has no connection with Linear Technology

Updated to 2.08 - Corrected total-network phase error, minor interface and printed-output improvements

Updated to 2.07 - Simplified input-termination entry now based only on power and peak plate swing

Updated to 2.06 - Correct item-placement errors on high-resolution monitor screens

Updated to 2.05 - Add inductor-winding routine, clarify volt and amp stress numbers.

Updated to 2.04 - Add peak voltage across each capacitor and RMS current through every part, based on the power entries.

Updated to 2.03 - Add significant help screen for input termination (plate load) entry; you may specify voltage and power (or voltage and current) and have the progran calculate the input termination.

Updated to 2.02 Show phase angles during tuning, allow save/get data plot for comparison

Released as 2.01 - 1 February 2006