Radio
Communications
Chapter 1
Introduction to Radio

INTRODUCTION TO RADIO




Communications an important part of
everyday life
Radio has revolutionised communication
The Air Cadet Organisation has its own nation
wide system of radio stations
This Network uses High Frequency for long
range
NETWORKS (NETS)
The word network is used because
NETWORKS (NETS)

Directed (Controlled) Net

Free Net
NETWORKS (NETS)

Directed Net :
• Controlled by the Network Control Station (NCS)
• A group of Stations using the same frequency
• Always controlled
• You must ask Permission to join and leave the Net
NETWORKS (NETS)

Directed Net :
• The Network Control Station (NCS) Should:

Have efficient equipment

Have experienced operators

Volume of radio communications to be passed
HF Base Station for Long Distance
NETWORKS (NETS)

Free Net
• No NCS (Network Control Station)
• No permissions required
• All Stations “Free” to contact each other
NETWORKS (NETS)
MRL 47
MRH 67
Free Net
MRK 17
MRK 92
NETWORKS (NETS)

Directed Net
To communicate with another Station
• You must have permission of the NCS
The NCS will do most of the communicating
NETWORKS (NETS)
MRL 47
MRH 67
Directed
MRV 92
NCS
MRK 17
MRK 92
NETWORKS (NETS)

Air Cadet Radio Nets
• Enable you to learn and practice procedures
• Techniques are based on Allied Military
Procedures
• Assist with our activities and safety
• Do not use non-standard procedures
Radio Station

A Radio Station is the smallest part of a
Net

It will have at least one radio set

The set will be able to transmit & receive

The set is known a a Transceiver
VHF Communications
Radio Station

Should use similar procedures for:
• High Frequency (HF) used for Long Range
• Very High & Ultra High Frequencies used for
Short Range

Directed Nets are more suited for HF
Radio Spectrum

Air Cadet Frequencies are:
• Assigned by the Ministry of Defence
• Are in the following bands:
Medium Frequency
 High Frequency
 Very High Frequency
 Ultra High Frequency

Radio Spectrum
Medium
(MF)
300Khz
to
3Mhz
High
(HF)
3MHz
to
30Mhz
Long Range
Very High
(VHF)
30MHz
to
300MHz
Ultra High
(UHF)
300MHz
To
3GHz
Short Range