User Defined Tubes

The last entry in the previous list was "User Defined." When this "triode" selection is made, the eight edit boxes in the "User Defined Triode" section are enabled. (They are normally disabled, but still show each selected tube's attributes.) User defined triodes use a fairly simple math model similar to many SPICE models, not the much more complex and much more accurate True Curves™ math model, which all the predefined triodes use. Still, if your favorite tube is not on the list, this option allows you to define your own model to be used in the simulations. (Setting the plate-curves graph to display only a single tube and then using the zoom tool, helps in trying to match a set of curves you might have for the tube.)

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Memory

Imagine that you have come up with the best compromise between performance and life expectancy. What do you with the recipe? You could write it down or you could save it to a file. TCJ Push-Pull Calculator has its own file format, with the extension: PPC. This means that you can email friends your latest design.

      Another possibility is to save the circuit to one of the ten scenario slots, which are also saved to the hard drive for later retrieval. But unlike files, their number is limited to ten and they cannot be emailed. Think of the scenarios as a quick scratch pad for when you think that some arrangement might be worth saving or when you wish to quickly compare competing designs with different tubes or topologies. Once you have the winner, save the scenario to a file.

Array options

TCJ Push-Pull Calculator allows creating an array of simulations. Eight variables are selectable for array building, as shown in the screen capture to the left. Once a variable has been selected, its maximum and minimum values can be defined, then the number of increments is entered. And that's it. In this example, the program will run seven simulations, starting with a seven volt input signal; and after eight simulations, using increments of 10 volts, end with an 87 volt input signal.

      The 3rd and 4th variables are disabled, as they are only needed when the circuit topology involves either an output transformer or cathode resistor.

      Once you get use to running an array of simulations, you'll become addicted.  One caution worth mentioning is that an array of 87 simulations, for example, will take some time to run. Therefore, don't create an array wherein the B+ voltage is incremented by 1 volt from 1 volt to 600 volts.