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OUTPUT(1)		     General Commands Manual		       OUTPUT(1)

NAME
     output - Yagi-Uda project antenna display program

SYNOPSIS
     output  [	- cehps  ]  [ -EE_max ] [ -HHmax ] [ -rminimum ] [ -Rmaximum ] [
     -ZZo ]

     filename

DESCRIPTION
     The program output 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.
     output calculates the gain, FB ratio, input impedance etc etc of an antenna
     that  was	described  by the program input or first and has had the element
     currents calculated with the program yagi The data about the forward  gain,
     VSWR, FB ratio, input impedance etc is written to a file filename.dat Angu-
     lar  data,  giving  the  variation of gain with theta and phi is put into a
     file filename.gai
     Sometimes the program fails to find the 3dB  bandwidths  in  the  E  and  H
     planes, and bombs out with a 'zbrent' error. This can occur if:
     (1)  The  antenna	has an almost isotropic pattern, in which case its never
     3dB down, so the 3dB point is undefined.
     (2) The 3dB point is outside the assumed angular range.  You then	have  to
     either:
     (a)  Calculate  with  the -e option, which avoids calculation of the 3dB E-
     plane beamwidth or
     (b) Do (a) above, then find approximately where the 3dB point is (from  the
     .gai file -see later), then set options -E and -H so the program calculates
     them properly.

     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. The DOS
     files are no longer being maintained, so are out of sync  with  the  latest
     source.

OPTIONS
     -c     Calculate  the  maximum level of any sidelobe - not just the rear on
	    as the FB ratio tells us. If the sidelobe and FB ratio are equal, it
	    means the biggest sidelobe is the rear one. If the Sidelobe is  less
	    than  the  FB  ratio, then another lobe is more significant. Look in
	    the '.gai' file (see below) to see where it is.  This  option  slows
	    the program quite a bit.

     -e     Suppress calculation of the 3dB E-plane bandwidth. This is sometimes
	    necessary  if the programme is unable to find the 3 dB beamwidth, to
	    prevent an error occuring.

     -h     Suppress calculation of the 3dB H-plane bandwidth. This is sometimes
	    necessary if the programme is unable to find the 3 dB beamwidth,  to
	    prevent an error occuring.

     -p     Put  data  into a file filename.freq for reading into gnuplot, and a
	    commmand file filename.gc for gnuplot to use. (run 'output -p  file-
	    name' then 'gnuplot filename.gc' )

     -s     Suppress  all  diagnostic  output. By default, the program print the
	    percentage of the job completed.

     -EE_max
	    When the program computes the E-plane 3dB beamwidth, it assumes  the
	    antenna pattern is 3dB down somewhere in the range 90 to Emax, where
	    E_max  is  by  default 179 degrees. This can fail if it is never 3dB
	    down in the range, or if it happened to go 3dB down in two	or  more
	    points.  You  can  change E_max, if you need to, but rarely if every
	    should need to. I've never seen a failure  here,  but  are	guarding
	    against  one.  If  you  dont want the pattern, use the -e option in-
	    stead, which skips it. See also '-H' below.

     -HH_max
	    When the program computes the H-plane 3dB beamwidth, it assumes  the
	    antenna  pattern is 3dB down somewhere in the range 0 to Hmax, where
	    H_max is by defualt 60 degrees. This can fail if  it  is  never  3dB
	    down  in the range, or if it happended to go 3dB down in two or more
	    points. Also, if it goes more than 3dB down, but that starts to come
	    up again. You can change H_max, if you need to, as failures do occa-
	    sionally occur. If you dont want the pattern use -h option	instead,
	    which will skip it.
	    An	obvious  example of an antenna where you cant find the 3dB band-
	    width for the H-plane is the 1ele dipole. The radiation is symmetri-
	    cal about its axis, so the level is the same  everywhere  in  the  H
	    plane.  The  program automatically avoids calculating it for a 1 ele
	    beam.

     -ZZo   Zo is the characteristic impedance used when calculating  the  VSWR.
	    By	default  it's  50 Ohms, but can be changed to any real, positive
	    value.

      filename
	    is the name of the file containing the antenna  description.  It  is
	    expected  to  be  in  a format created by input or first - two other
	    programs in the Yagi-Uda project.  The is also expected to	exist  a
	    binary file filename.out created by typing yagi filename

Limitations
     I'm not aware of any limitations, apart from that filenames, including full
     path, can't exceed 90 characters.

FILES
     filename	     ASCII file with antenna description.
     filename.out    Binary data file, created by yagi.
     filename.dat    ASCII file with gain, FB ratio etc.
     filename.gai    ASCII file with angular dependence of gain.

SEE ALSO
     first(1), input(1), yagi(1), optimise(1).

PLATFORMS
     Both  DOS and Unix versions have been built. The DOS version as distributed
     requires a 386 PC with a 387 maths coprocessor.

BUGS
     Bugs should be reported to 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.	The program gives errors
     if element lengths are well away from a half-wave (by a factor of	~3)  due
     to  a breakdown in the equations.	If the input file is edited manually and
     done incorrectly, there can be unpredictable results.

AUTHORS
     Dr. David Kirkby G8WRB (david.kirkby@onetel.net).	with help with	convert-
     ing to DOS from Dr. Joe Mack NA3T (mack@fcrfv2.ncifcrf.gov)

Version 1.16			24th October 2000		       OUTPUT(1)

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