Radio Communications

Chapter 1 Introduction to Radio

Introduction To Radio Radio has revolutionised communication The Air Cadet Organisation has its own nation wide system of radio stations This Network uses High Frequency (HF) for long range Communications an important part of everyday life Introduction to Radio 1. Communications are an important part of everyday life. We constantly need to pass on information, thoughts and ideas from one person to another. This is particularly important in a military environment, where intelligence of enemy activity can play an important role in the success or failure of a mission. 2. The invention of radio has revolutionised communication for everybody. Using radio waves, people can now communicate all over the world with relative ease. Radio is not the only means of communications in this day and age. The telephone (including the mobile phone), internet, facsimile (fax) and video all play an important part. This section introduces you to radio communications, its limitations and its benefits. Radio systems can be used to transmit various types of data as well as voice. As a Cadet you will learn how a simple radio system works and how to operate it correctly, efficiently and safely. 3. The Air Cadet Organisation is fortunate, in that it has its own nation wide system of radio stations and usually operates on most Sunday mornings. This system was originally set up just after the Second World War to train Cadets in the use of High Frequency (HF) radio equipment, and is called a "network".

The word network is used because Networks (Nets) The word network is used because A number of radio stations are working together, connected by the invisible strands of a single frequency - rather like a net. Networks The word network is used because a large number of radio stations are working together, connected by the invisible strands of a single frequency - rather like a net.

Networks (Nets) Directed (Controlled) Net Free Net Where the control station directs all of the communications Free Net Where each station is free to communicate as it needs. Networks (Nets) There are two types of Nets: Directed (Controlled) Net Where the control station directs all of the communications Free Net Where each station is free to communicate as it needs.

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) 4. A Directed Network (Net) is a group of radio stations each operating on the same frequency for the purpose of communicating with each other. A Directed Net is always "CONTROLLED", i.e. there will always be a "Network Control Station" (NCS) controlling the radio communications. Stations must be given or must obtain permission from the NCS before communicating with another station on the Net. It is also necessary to ask permission when joining and leaving the Net.

Networks (Nets) Directed Net : The Network Control Station (NCS) Should: Have efficient equipment Have experienced operators Be able to handle the volume of radio communications to be passed Net Control Station Only one station on the network can act as the NCS (network control station) at any one time. A number of factors will dictate which station is chosen to undertake the NCS duties for any specific occasion. Some of these factors include: a. Equipment efficiency. b. Operator experience. c. Volume of radio communication to be passed. 6. It is usual for the NCS to be a fixed base station, located in a room intended specifically for radio operations - the radio communications room.

Networks (Nets) Free Net No NCS (Network Control Station) No permissions required All Stations “Free” to contact each other 7. A network operating without a NCS is called a “Free Network” (Free Net). Here, each of the stations is permitted to contact any other station they wish without permission from the NCS

Networks (Nets) MRL 47 MRH 67 Free Net Free Network 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 Directed Network 8. On a Directed Net, stations may only communicate with the prior permission of the NCS who will dictate priorities and orders. This means that NCS will do most of the communicating as they will be the first point for any message.

Directed Networks (Nets) MRL 47 MRH 67 MRV 92 MRK 17 MRK 92 NCS All messages must be sent with the permission of the NCS in this case MRV 92 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 9. The Air Cadet radio network has been established to encourage Cadets to learn and practice the art of radio communication using radio techniques based on the Allied Military radio procedures. Used correctly, the information and instructions transmitted can be of vital importance in assisting in the safe and successful operation of your activities. However, the use of non-standard procedures and phraseology could cause misunderstanding with potentially dangerous consequences. In addition to this, the Services must always be aware that a potential enemy may be able to receive the transmitted information, and use it to their advantage.

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 10. From this you can see that the radio station is the smallest part of any radio network. The station will have at least one radio set capable of transmitting and receiving and which is generally known as a transceiver

HF Base Station for Long Distance Radio Station HF Base Station for Long Distance

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 11. This first chapter has explained, in simple terms how an HF Net operates. Similar procedures can be used when using Very High Frequencies or Ultra High Frequencies (VHF/UHF) equipments and the rest of this book will be based around VHF/UHF equipments.

Operating from a remote location VHF Communications Operating from a remote location

Radio Spectrum Air Cadet Frequencies are: Assigned by the Ministry of Defence Are in the following bands: Medium Frequency (MF) High Frequency (HF) Very High Frequency (VHF) Ultra High Frequency (UHF) Radio Spectrum Frequencies 12. The Air Cadet Organisation has a number of frequencies assigned to them by the Ministry of Defence. These frequencies are in the Medium, High, Very High and Ultra High parts of the Radio Spectrum.

Radio Spectrum Medium (MF) High (HF) Very High (VHF) Ultra High (UHF) 300Khz to 3Mhz 3MHz 30Mhz 30MHz 300MHz To 3GHz 13. The Radio Spectrum is broken down into frequency bands and the chart below shows the breakdown: Medium High Very High Ultra High 300Khz 3MHz 30MHz 300MHz to to to to 3MHz 30MHz 300MHz 3GHz Only the part of the spectrum where the Air cadets use frequencies is shown. There are frequency bands either side of those shown but you do not require knowledge of these for this course. In simplistic terms: Lower the Frequency Longer the Range Higher the Frequency Shorter the Range Long Range Short Range

Introduction to Radio End Ready for operating