As radio amateurs in the UK, we must ensure our stations comply with Ofcom’s licence conditions regarding Electromagnetic Field (EMF) safety. This means we need to check that the radio signals we transmit do not expose the general public to energy levels above international safety guidelines.
This simple guide will help you complete your station assessment step-by-step.
Step 1: Gather Your Shack Data
Before using the compliance tools, write down the following details for your highest-power or most-used setup:
- Radio Model: (e.g., Icom IC-7300)
- Maximum Transmit Power (Watts): (e.g., 100W)
- Antenna Type: (e.g., Half-Wave Dipole, End-Fed Half Wave, 2m Collinear)
- Antenna Gain (dBi): (If unknown, use standard averages from the RSGB tools)
- Feeder Cable Type & Length: (e.g., 15 metres of RG-213)
Step 2: Use the RSGB Calculator
The easiest way to check compliance is to use the official spreadsheet EMF Calculator developed by the Radio Society of Great Britain (RSGB) EMF Calculator.
- Visit the RSGB EMF Compliance Page.
- Download the latest version of the RSGB EMF Calculator.
- Input your frequency band, power, cable loss, and antenna gain.
- Look at the calculated Compliance Distance (the safe zone radius).
Step 3: Map Your Compliance Distance
The compliance distance is the minimum distance required between your antenna and any member of the public (including neighbours and people on public pavements).
- Example: If the calculator says your 20m dipole has a compliance distance of 2.4 metres, you must ensure the general public cannot get closer than 2.4 metres to any active part of that antenna while you are transmitting.
- Height Counts: If your antenna is high up on a mast or roof, the distance from the antenna to a person on the ground counts toward this safe distance!
Step 4: Download and Save Your Record
You do not need to send your results to Ofcom, but you must keep a record of your assessment in case they ever ask to see it.
Use the quick log sheet template below to record your station’s compliance.
Tip: Print your completed table or save it as a PDF on your computer next to your radio logbook.
SADARS EMF Safety Assessment Record
Fill out this interactive log sheet directly in your browser. Once completed, click the button at the bottom to neatly print it out or save it as a PDF document alongside your main radio logbook.
Frequently Asked Questions
Do I need to do this for my 5W handheld radio?
If your equipment cannot transmit more than 10 Watts ERP (Effective Radiated Power) or 6.1 Watts EIRP, you are generally exempt from keeping detailed records, but it is still good practice to understand your safe distances.
What if my antenna is close to a public footpath?
You can lower your transmit power, use a less directional antenna, or move the antenna further back into your property to make sure the compliance zone stays completely within your boundary.
Where can I get help?
If you get stuck with the math or the spreadsheet, bring your station details down to the next SADARS club night. Our experienced members will gladly help you run the calculations!