NAME

       first - Yagi-Uda project quick antenna builder

SYNOPSIS

       first filename  elements f_min f_design f_max f_step diameter

DESCRIPTION

       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.

LIMITATIONS

       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.

FILES

       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.

PLATFORMS

       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.

AUTHORS

       Dr. David Kirkby G8WRB (david.kirkby@onetel.net).  with help with the  conversion  to  the
       DOS/PC environment from Dr. Joe Mack NA3T (mack@fcrfv2.ncifcrf.gov)

SEE ALSO

       input(1), output(1), yagi(1), optimise(1).

BUGS

       Bugs  should  be  reported  to:  David  Kirkby G8WRB (david.kirkby@onetel.net).  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!