What changed
RFI and noise — edited Aug 31, 2026 by Unknown editor
This is the first recorded version, so every line is shown as added. Note: Imported from content/wiki
+
Modern suburban noise floors are appalling. Almost all of it is local, and almost all of it is
+
fixable — it is coming from something in your own house or a neighbor's.
+
+
## Common sources
+
+
- Switch-mode power supplies and phone chargers (buzzing across whole bands)
+
- LED and fluorescent lighting, and dimmers
+
- Solar inverters and EV chargers
+
- Plasma TVs, ethernet-over-mains adapters, aquarium heaters
+
- Utility pole hardware — arcing insulators produce a rasping buzz over huge distances
+
+
## Finding it
+
+
1. Kill the main breaker and listen on a battery radio. If the noise stops, it is yours.
+
2. Restore circuits one at a time.
+
3. Outside the house, use a portable receiver on AM or a handheld with a directional antenna and
+
walk the noise down.
+
4. Utility noise: log the times and directions, then report it to the utility. They have RFI teams,
+
and arcing hardware is a fire risk they care about.
+
+
## Fixing it
+
+
- Ferrite chokes on the offending device's power and data cables.
+
- Replace the cheapest offenders — a $6 charger causing S7 noise is not worth defending.
+
- A receive-only antenna (loop, flag) sited away from the house helps on the low bands.
+
- Noise blankers and DSP noise reduction help with some noise types and none of the others.
+
+
## Interference you cause
+
+
If a neighbor reports interference: be polite, respond immediately, and get on their side of the
+
problem. Most cases are poor immunity in consumer equipment rather than a fault in your station, but
+
"the FCC says it is their problem" has never once ended well. Filters, chokes, reduced power and a
+
friendly manner solve nearly all of it.