first(1) Yagi-Uda project quick antenna builder


first filename elements f_min f_design f_max f_step diameter


The program first is one of a number of executable programs that forms part of a set of programs, collectively known as the Yagi-Uda project , which were designed for analysis and optimisation of Yagi-Uda antennas. first is used to define an antenna quickly, if you are not interested in analysing a specific design (in which case use input ) but need to get a design that is half-way reasonable so that it may be optimised. It is much faster in use (since its not interactive) than input The design methodology that first is the DL6WU antenna designs, which are valid for 10 or more elements, although first will calculate for any number of elements. DL6WU reccomends a folded dipole, but the designs here are for a simple dipole, since I don't yet know how to calculate the self and mutual impedances of folded dipoles.


Filenames, including full path, can't exceed 90 characters.

Does not take into account the variation of impedance of a dipole with change in wavelength/diameter of elements.


filename          Yagi description, created by first.
filename.out      Binary data file, created by yagi.
filename.dat      Performance of antenna, created by output.
filename.gai      Gain of antenna, created by output.

The DOS .EXE files as distributed require a 387 maths coprocessor to be present and will not run without it. A 486, Pentium, and I assume later processors of this series will run it without any extra hardware.


Both DOS and and Unix versions have been built. The DOS version as distributed requires a 386 PC with a 387 maths coprocessor. The DOS version is no longer being developed, so the DOS executables included with the distribution are not upto date with the current source code.


Dr. David Kirkby G8WRB ([email protected]). with help with the conversion to the DOS/PC environment from Dr. Joe Mack NA3T ([email protected])


Bugs should be reported to: David Kirkby G8WRB ([email protected]). Bugs tend actually to be fixed if they can be isolated, so it is in your interest to report them in such a way that they can be easily reproduced.

If the input file is edited manually and done incorrectly, there can be unpredictable results.

Options are not checked for sensible numbers. A negative length can be entered!