Electromagnetic radiation (EMR) is the mechanism by which radio waves are emitted and propagated.
Exposure to high levels of EMR can be dangerous for humans. ACMA regulates levels of human exposure to EMR through their Radiocommunications Licence Conditions (Apparatus Licence) Determination 2015, which calls up the following Australian standard:
Radiation Protection Standard for Maximum Exposure Levels to Radiofrequency Fields—3 kHz to 300 GHz
The standard is published by the Australian Radiation Protection and Nuclear Safety Agency.
Compliance levels for Amateur stations
The standard sets out two compliance levels for the operation of radio transmitters:
Compliance level 1
Compliance level 1 applies to stations where:
- the average total power supplied by the transmitter is not more than 100 W; and
- each antenna fed by the transmitter is installed so that it is inaccessible to a member of the general public.
- the bottom of the lowest antenna fed by the transmitter is at least 10 m above ground level; and
- the average total equivalent isotropically radiated power (EIRP) of all antennas fed by the transmitter is not more than 3200 W in any direction.
Compliance level 1 also applies to a mobile station for which the average total power is not more than 100 W.
Standard and Foundation stations comply with level 1 automatically, as long as their antennas are behind a fence.
For Advanced stations, given that the average power produced by a 400W SSB transmitter is less than 100W, if you operate at no more than 100W on FM or any other mode with a carrier or high duty cycle (FT8, for example) and your antenna is behind a fence, you will comply with level 1.
If your station complies with level 1, there is no requirement to keep records.
However, for Advanced stations, if you are using high gain antennas (stacked yagis on VHF, for example), with an EIRP of 3.2 kW or more, and the antennas are less than 10m above the ground, your station does not meet the level 1 requirements.
Compliance level 2
If your station does not meet level 1 requirements, it is classified as level 2. You are required to prove that your station complies with the Australian standard and maintain records to this effect.
ACMA have produced a simple RF exclusion zone calculator. The exclusion zone is an area where EMR levels may exceed the Australian standard.
The calculator may be found at the bottom of this page on the ACMA website: