The symbols and subcircuits folders are found ... (Wiley, New York, 1954), 881 pages. 4. Jacob Millman, Vacuum-tube and Semiconductor Electronics (McGraw-Hill, New York, 1958), 644 pages.

In Part 3 of this series, covering the simulation of vacuum tubes in SPICE, 7 we outlined the construction of a model for a VT triode―quite conveniently, the 12AX7. With the symbol(s ...