Hissing / mono / fading on FM radio


This type of interference normally indicates weak FM signals. Apart from some remote areas, the UK generally enjoys good FM coverage. Therefore, if you are experiencing weak signals it is usually due to one of these factors:-

  • Reduced transmitter power
  • An aerial problem
  • Bad radio positioning
  • Tuning to the wrong transmitter

What to do

  • Ensure your transmitter is not on reduced power by using our Transmitter Fault Checker.
  • If you are using an FM tuner as part of a HiFi system, check your aerial. It may be broken or pointing in the wrong direction, or the cable may be broken or loose. Even loft aerials can suffer corrosion, especially at the connecting terminals. If the problem tends to occur when it rains but clears up completely after a dry spell, water may be getting into your aerial downlead.
  • If you are using a HiFi tuner and stereo reception is hissy but mono is fine, your aerial may not be powerful enough. We do not recommend the use of ‘ribbon'-type indoor aerials for stereo FM reception as they rarely give good results. A properly-made outdoor, or even a loft aerial, connected to your receiver with co-axial cable is better.
  • If your radio is a portable, make sure the aerial is fully extended. If it's hinged, try moving it to different angles.
  • The telescopic aerial fitted to stereo portables is a compromise and the radio will often only give really good results if connected to an external aerial. If that's not possible, switch to mono as it will usually sound better.
  • If you're using a portable, try a different position in the room. Windowsills and high shelves are good places for radios; avoid putting them close to radiators or electronic equipment such as computers, mobile/cordless phones or TV sets.
  • Make sure you are tuned to the best frequency for your area, as you can often pick up more than one signal. You can find out more at by visiting the Reception Advice website radio section  

*For help with aerials we would recommend using a professional installer. We cannot recommend individual installers but you may wish to seek advice from a recognised industry body, such as the Confederation of Aerial Industries (CAI).

How would you rate the usefulness of this answer

Poor Excellent

Transmitter Checker

Enter postcode and platform below to check for faults with your local transmitter (Format: AB12 2AA)

For information on how we use your postcode (and any other personal data you may provide to us), check the 'How we use your personal information' section on our 'About Us' page.

Problem Assistant

Get started with diagnosing your problem with our self-help tool.

Launch the tool by clicking here