The Basic lessons · Interference and suppression · B-008-002

Stopping RF Interference in Home Electronics

Learn why strong radio signals turn into noise in your speakers and phones. Discover the simple ferrite cores and filters that stop these unwanted sounds.

This lesson is part of SignalPrep Pro. The subsection's 11 exam questions are free to practise: practise B-008-002.

What this subsection asks

• What devices would you install to reduce or eliminate interference to a home entertainment system from an HF transmitter?
• What should be done if a properly operating amateur radio station is the cause of interference to a nearby telephone?
• What sound is heard from a public address system if audio rectification of a nearby single-sideband transmission occurs?
• What sound is heard from a public address system if audio rectification of a nearby CW transmission occurs?
• If an amateur radio transmission is heard in a device that contains no RF components, what type of interference is this?
• An amateur radio transmitter is being heard across the entire dial of a broadcast receiver. The receiver is most probably suffering from:
• Your SSB HF transmissions are heard muffled on a sound system in the living room regardless of its volume setting. What causes this?
• What device can be used to minimize the effect of RF pickup by audio wires connected to stereo speakers, intercom amplifiers, telephones, etc.?
• Stereo speaker leads often act as antennas to pick up RF signals. What is one method you can use to minimize this effect?
• One method of preventing RF from entering a stereo set through the speaker leads is to wrap each of the speaker leads:
• Stereo amplifiers often have long leads that pick up transmitted signals because they act as: