[RFI] Sinusoidal type noise on 6 meters (wx3k at yahoo.com) from [Jim Brown]

[Chris L. Parker]

Stephanie,

Jim brings up many good observations.

My goal here is simply to provide you guidance to help you resolve your RFI issue.

With the RFI present, connect your rig to run off battery power, and then turn off the main circuit breaker to your residence.

This should be a 100 amp or 200 amp main circuit breaker, depending on your service.

This should eliminate and rule out any AC-powered source inside your residence. (watch out for battery powered uninterruptible power supplies) Check (or have another person check via cell phone conversation) to see if the RFI goes away. If it does, then turn off all the sub-panel breakers, turn on the main breaker, and then turn on the sub-panel breakers one-by-one until the RFI returns. This will locate the room or circuit that is causing the RFI. Then use detective work and check all devices plugged into that particular circuit. (an appliance may be hard wired in, like ovens, or under counter lighting, or have hidden plugs, like refrigerators)

If the RFI is still present with the main breaker off, then most likely it is an external source. A directional antenna could help locate the source. A beam (large at 6M), small loop (see "Handheld Direction Finding Loop Antenna for RFI Location" Gary W. Johnson, NA6O) or perhaps DX Engineering NOISELOOP Portable Receive Flag Antenna Kit based on the design by Don Kirk, WD8DSB could be of service.

I suggest keeping an RFI notebook recording date, time, frequency or frequencies affected, signal strength, characteristics of noise, weather conditions (humidity and temperature) whether engaging noise blanker affects it, etc.

Hope this helps.

Chris
AF6PX
ARRL RFI PLN Technical Specialist, Los Angeles Section