8.2 Frequency and Emission

Foundation Licence Frequencies and Emissions: In Australia, the Foundation Licence allows amateur radio operators to use specific frequencies and modes of emission. It is crucial for operators to be aware of these allowances to ensure compliance with regulations and to avoid causing interference to other users.

Allowed Frequencies: Foundation Licence holders are permitted to operate on certain HF, VHF, and UHF bands. These frequencies are allocated to ensure that operators can engage in a variety of communication activities while minimising interference with other services.

HF Bands:

• 80 metres (3.5-3.7 MHz): Suitable for long-distance communication, particularly during night-time conditions.
• 40 metres (7.0-7.3 MHz): A versatile band for both local and international contacts, especially effective during daytime and early evening.
• 15 metres (21.0-21.45 MHz): Offers good propagation for international communication, particularly during daytime.
• 10 metres (28.0-29.7 MHz): Provides opportunities for long-distance communication, often open during periods of high solar activity.

VHF Bands:

• 2 metres (144-148 MHz): Commonly used for local communication, including repeaters and simplex contacts.
• 6 metres (50-54 MHz): Sometimes referred to as the “magic band” for its unpredictable propagation characteristics, allowing both local and long-distance communication.

UHF Bands:

• 70 centimetres (430-450 MHz): Used for local communication, including repeaters, and is known for its ability to penetrate buildings and urban environments.

Allowed Emission Modes: Foundation Licence holders are permitted to use several emission modes, each suited to different types of communication.

Voice Modes:

• Amplitude Modulation (AM): A traditional mode of voice communication, though less commonly used today due to its susceptibility to noise.
• Single Sideband (SSB): A form of AM that is more efficient and provides better long-distance communication quality.
• Frequency Modulation (FM): Commonly used on VHF and UHF bands for clear local communication, especially through repeaters.

Data Modes:

• Morse Code (CW): An enduring mode for long-distance communication, valued for its simplicity and effectiveness under poor conditions.
• Digital Modes (e.g., PSK31, FT8): Increasingly popular for their efficiency and ability to communicate under weak signal conditions.

Listening Before Transmitting: Before transmitting, it is essential to listen to the frequency to ensure it is not in use. This practice helps avoid causing interference to other operators who may already be communicating. Observing proper operating etiquette and respecting other users’ transmissions fosters a cooperative and enjoyable operating environment.

Operating Tips:

• Frequency Check: Always verify that the frequency is clear by listening for a reasonable period before transmitting.
• Identify Regularly: Clearly identify your station at the beginning and end of your transmission, and periodically during longer communications.
• Use Appropriate Power: Use the minimum power necessary to maintain effective communication, reducing the risk of interference.