The codice_15 line then sets the test frequency to 46.29 MHz. codice_15 lines can optionally define the number and magnitude of the frequency steps if the system is being used to analyze the performance across a range of frequencies, but this is not being used in this case. The codice_17 lines (transmission line) connect the various elements together. These can be seen on most log-periodic designs in the form of two thin rods running down the boom between the main antenna elements, although some designs use the boom itself, or hide the wires within the boom. The codice_18 (excitation) line indicates the location of the energy supplied to the design, in this case an incoming plane wave being captured on segment 10, while the codice_19 (radiation pattern) sets up some specifics of the signal.