User's Manual
Table Of Contents
- Table of contents
- List of figures
- List of tables
- Introduction
- 1 NGTtransceiver compliance
- 2 Installation
- 3 The handset
- 4 Getting started
- Switching on the transceiver
- Changing the screen contrast
- Changing the screen brightness
- Using the keys on the handset
- Accessing the Main Menu
- Switching scanning on or off
- Switching mute on or off
- Entering your station self address
- Listen Before Transmit Mode
- Replacing LQA information for all channels in an ALE/CALM network
- Making a manual sounding operation in an ALE/CALM network
- Selecting the best channel in an ALE/CALM network
- Making a Selective call from the Address List
- Making a Phone call from the Address List
- Making an emergency call using the emergency key
- Using a special ALE address syntax to make a call
- Appendix A— Standard hot keys
- Appendix B— Entering and editing text
- Appendix C— Finding words and values
- Appendix D— Creating an entry in a list
- Appendix E— HF radio transmission
- Appendix F— Definitions
- Index
NGT ASR Transceiver Getting Started Guide 73
CODAN
Appendix E—HF radio
transmission
The HF band is the range of frequencies between 3 and
30 MHz. HF transceivers usually cover a frequency range of
1.6 to 30 MHz.
Codan HF transceivers transmit on single sidebands. This
reduces the power required to send HF signals and increases
the number of channels available within the HF spectrum.
HF transceivers are primarily used for long-range
communication where distances of 3000 km and more are
possible. Obstructions such as buildings and mountains have
little effect on long-range communication. HF radio can cover
such large distances because of the way the transmitted radio
signal propagates.
HF radio waves propagate in three ways simultaneously:
• ground wave
• direct wave
• sky wave
Ground wave
The ground wave travels near the ground for short distances,
typically up to 100 km over land and 300 km over sea. The
distance covered depends upon the operating frequency,
transmission power and type of terrain.
Direct wave
The direct wave travels in a direct line-of-sight from the
transmitter to the receiver.