## NAME

         first - Yagi-Uda project quick antenna builder

## SYNOPSIS

         first filename  elements f_min f_design f_max f_step  diame-
         ter

## 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  optim-
         ised.  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 copro-
         cessor  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 ver-
         sion  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 enviroment 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!