You've eliminated every noise source in your own house. Switched off the main breaker, and the noise is still there. S7 hash across 40 meters. Buzzing on 20m. A rhythmic clicking every 3 seconds on 80m.

It's coming from somewhere else. A neighbor's house. A power line. A commercial building down the street. Now what?

This is the most frustrating problem in amateur radio. You've done everything right on your end, and someone else's broken gear is wiping out your bands. I've been through this three times. One resolved beautifully. One took eight months. One I eventually gave up on and moved my antenna.

Step 1: Characterize the Noise

Before you do anything else, document what you're hearing:

  • Frequency range: Does it affect all bands? Only HF? Specific bands?
  • Pattern: Constant? Intermittent? Time-of-day correlation?
  • Sound: Buzz (power supply switching), hash (broadband), clicking (arcing), whine (motor)?
  • S-meter reading: How bad is it? S3 background? S9 brick wall?
  • Directional? If you have a beam, does it null in a specific direction?

Write this down. Take recordings. Screenshot your waterfall display if you have one. This documentation matters later if you need to involve the FCC or your utility company.

One mistake I made early on: assuming it was one source. Spent weeks tracking what I thought was a single noise on 20m. Turned out to be three separate sources from three different directions that happened to overlap in frequency.

Step 2: Is It Power Lines?

Power line noise is the most common external RFI source. Characteristics:

  • Broadband buzz/hash, loudest on lower HF (160m, 80m, 40m)
  • Gets louder when it rains or is humid (arcing increases with moisture)
  • OR gets louder when dry and windy (loose hardware vibrating)
  • Constant — doesn't turn off at night
  • Usually directional — follows the line route

If you suspect power lines: your utility company is obligated to investigate and fix interference from their equipment. This is federal law (FCC Part 15). Call their engineering department — not customer service. Ask specifically for their power quality or RF interference team.

Some utilities respond within weeks. Others drag for months. Documentation (recordings, direction-finding results, dates/times) dramatically increases your chances of getting action.

Step 3: Locating the Source

You don't need expensive equipment to narrow down an interference source.

AM broadcast radio method: Tune a portable AM radio between stations where you can hear the noise. Walk around your neighborhood. The noise gets louder as you approach the source. Crude but surprisingly effective for strong sources.

HF portable receiver: A QRP rig or portable receiver with an S-meter and a small loop antenna. Magnetic loops have sharp nulls for direction finding. Walk the neighborhood, note where the signal peaks.

Dedicated RFI locator: The ARRL Technical Information Service has loaner RFI equipment for members. Some ham clubs own direction-finding gear. A cheap RTL-SDR dongle with a small antenna makes a decent RFI hunter.

I located my worst interference source — a faulty LED grow light power supply in a neighbor's garage — using an IC-705 with a small magnetic loop, walking around at 11pm in January. Probably looked insane. Got the job done.

Step 4: The Diplomatic Approach

You've identified the house. This is where most hams fail. Not technically — socially.

Do NOT show up angry. Do NOT lead with "your equipment is violating FCC regulations." Do NOT threaten legal action.

The script that's worked for me: "Hey, I'm [name] from down the street. I'm a ham radio operator and I've been tracking down some electrical interference. I've narrowed it to somewhere around your house. Mind if I take a look? I can probably fix it for free — and honestly, whatever's causing it might also be wasting electricity or creating a fire risk."

That fire risk angle reframes the problem as benefiting them. Most people don't care about your hobby. They do care about their electric bill and house fires.

Common Culprits

LED bulbs and dimmable LED drivers: Cheap switching power supplies in LED bulbs are the #1 new RFI source. Particularly dimmable LEDs and grow lights. Fix: replace with name-brand LEDs or add ferrite chokes to the power cord.

Solar panel inverters: String inverters and micro-inverters can produce HF interference. Legitimate installations should not — if they do, the installer should fix it under warranty. FCC Part 15 compliance issue.

Electric fence chargers: Clicking every 1-2 seconds. Usually arcing at a bad connection in the fence wire, not the charger itself. Find the bad insulator.

Power line adapters (Ethernet over power): Intentionally inject RF onto house wiring. Can radiate broadband noise on HF. Fix: remove them, use WiFi or proper Ethernet.

Switching power supplies: Wall warts, laptop chargers. Usually low-level individually but dozens add up. Ferrite snap-on chokes help.

Step 5: When Diplomacy Fails

FCC Interference Complaint: File via the FCC's online portal. Reference Part 15. Reality check: enforcement for individual cases is slow and rare. But file anyway — patterns of complaints matter.

ARRL Technical Information Service: Members can request assistance. They have experience mediating RFI disputes and provide official documentation that sometimes motivates action.

Utility involvement: For power line noise, file with both the utility and FCC simultaneously. Utilities respond faster to regulatory pressure.

Step 6: Mitigation on Your End

When you can't fix the source:

Receive antennas: A small receive loop (Wellbrook or DX Engineering RF-PRO-1B) has deep nulls. Orient the null toward the noise source. Use main antenna for transmit, loop for receive.

Noise canceller: Hardware noise cancellers (MFJ-1026, DX Engineering NCC-2) take a noise sample from a separate antenna and cancel it from your main signal. Works remarkably well for localized sources.

Antenna relocation: Moving your antenna 50-100 feet can put a building between you and the noise. House attenuation: 10-20 dB.

Higher bands: Most consumer RFI is worst on lower HF and decreases higher. If 40m is destroyed but 20m is usable — operate 20m.

Directional antenna: A Yagi's rear null can eliminate a fixed-direction interference source from your operating experience entirely. Point the back of the beam at the noise.

The Long Game

RFI from neighbors is a marathon. My eight-month case involved initial identification, two cordial visits, a partial fix (one LED replaced), an FCC complaint with no response for 4 months, and finally a solar inverter firmware update by the installer that killed the remaining noise.

Patience. Documentation. Diplomacy. In that order.

The ham community has decades of experience with this. Join your local club, ask if anyone has RFI hunting equipment. Having a second ham with you makes the whole process smoother and more credible to the neighbor.

And if all else fails: the best antenna is one pointed away from the noise.