path: root/README.md

# calctenna.py

## Calculate dipole antenna leg length

```text
usage: calctenna.py [-h] [-V velocity_factor] [-q] [-t] [frequency]

positional arguments:
  frequency             desired frequency in Hz (e.g. 144800000 or 433e6, ...)

optional arguments:
  -h, --help            show this help message and exit
  -V velocity_factor, --velocity-factor velocity_factor
  -q, --quiet           print only result
  -t, --tests           run unit tests and exit
```

### Example output

```text
$ calctenna.py 104e6
Desired Frequency: 104e6 Hz
Wavelength: 2.883 m
Wavelength / 2: 1.441 m
Wavelength / 4: 0.721 m
Velocity factor: 0.951
-> Dipole leg length (lambda/4): 0.685 m
```