---
name: "first"
section: "1"
platform: "linux"
package: "yagiuda"
version: "1.19-12"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/first"
---

# first(1)

Yagi-Uda project quick antenna builder

## 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)](/input/1.md), [output(1)](/output/1.md), [yagi(1)](/yagi/1.md), [optimise(1)](/optimise/1.md).

## 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!