---
tags: [ham-study]
---

## Earthing

Where a safety earth has been fitted, it must not be removed. If changes are
necessary, a competent professional must be consulted.

## Plugs, fuses and circuit breakers

Need to know the plug colours:

| Colour  | Cable            |
| ------- | ---------------- |
| Live    | brown            |
| Neutral | blue             |
| Earth   | green and yellow |

- The flex of the plug cable should be secured.

- The fuse must match the plug

- A fuse comprises a thin wire that melts when excessive current flows through
  it, breaking the circuit. When a fuse blows, you should investigate the cause
  and not just blindly replace especially if it is recurrent.

- Better than a fuse is a Residual Current Circuit Breaker with Overcurrent.
  This can detect currents to earth of over 30mA whereas a fuse just captures a
  few amps and only detects short circuits.

## General points

- Only work on the inside of equipment, having first disconnected the power
  source

- Have a master switch for all radio equipment

- Safety measures must be taken when using radio equipment outside

- Wear protective goggles when soldering

- Very high antennas require lightening protection

- Antennas and feeders must not be sited close to overhead cables

- A ladder should be used at a 4:1 height to base ratio and be used with an
  assistant

- The main health damage from EM radiation is heating of body tissue, especially
  the eyes

- Antennas and other conductors must not be touched when transmitting

- Antennas must not be mounted in such a way that people would accidentally come
  into contact with them

- You must not look down a wave guide