The kit (priced estimated at $35) includes:

  • 1 x 61mm ferrite core
  • 1 x 50mm ferrite core
  • 5 x large ferrite snap-ons
  • 5 x medium ferrite snap-ons
  • Application notes on the effective use of ferrite filters

This kit will help you reduce QRM from your transmitter, as well as reducing or even eliminating local QRM affecting your receiver.  These will be particularly effective is you are suffering common-mode noise, where interference enters your radio via the coax shielding.

If you suffer the following, a combination of these ferrites may help:

  • computer rebooting when you transmit
  • RF hot microphone or Morse code key
  • RF feedback affecting your own transmission
  • RF interfering with your computer screen
  • losing data control to/from your computer when you transmit
  • resetting or impacting your ADSL or NBN modem
  • interference to devices such as TVs, broadcast radios, garage door openers etc.
  • noise being radiated from LED lights and other consumer electrical products
  • noise travelling along your mains power

If your local QRM is persistent you may need to track it down and take remedial action at its source (e.g. LED lamps, garage door openers, wall-warts, switch-mode power supplies)

A good RF earth is also recommended.   We’re preparing stocks for these kits.  If you’d like to buy one, please register your expression of interest with an email to   We’ll bring them to club meetings and Hamfests.  We’ll also post (add $10 P&P to the price).

** We expect to have these kits ready by the end of February – email us and we’ll put your name on the list **