Thread: Isolating RFI noise

Isolating RFI problems.

Use a RFI noise sniffer. Most folks have one and don’t even know it.
The laymen name for the sniffer is called an AM radio.
Turn on your electronics. Turn on your hand held AM radio. Cheap radio works good.

Select a good conservative talk show. Move the radio around the boat wires in the boat and it will pick up the static source. The loudest static is the source of the noise.

Note that liberal talk shows won’t work as it is all static.

Take notes on this you HB reps.

Would that be the liberal talk shows part or the static?
Is there really a difference? :D :D

I use to know that. Completely forgot how handy an old transitor radio was.

Then what do you do after you find it?

Tune your radio to Rush Limbaugh and hope the static goes away?

Dunno if that will work... someone once told me not to spit into the wind, or pull on Superman's cape. Same theory I think.

Originally Posted by mduncan62

Then what do you do after you find it?

I'd say turn off things one by one until you isolate exactly which piece of
equipment is the guilty party, then you could try to seperate all it's wiring
from other stuff you don't want it bleeding over on. Other side of the boat,
or even a few extra inches betweent the wires might make a big difference.

On a side note, the Vexilar Edge III that came on my boat absolutely
drives an FM radio wild. Clicking and popping. But, it's probably as good
a sonar as I've ever used even though handicapped by an old school color screen...
It's not easy to see in sun, not real high pixel count either, but as far as
showing whats down there without clutter, it's top notch

Originally Posted by J White

I'd say turn off things one by one until you isolate exactly which piece of
equipment is the guilty party, then you could try to seperate all it's wiring
from other stuff you don't want it bleeding over on. Other side of the boat,
or even a few extra inches betweent the wires might make a big difference.

That is the way to do it.

Sometimes you have combination noise sources where several operating equipment combine to creates a noise. That when it gets hard. Ask any dealer.:D

What creates a lot of the noise trouble is the way the boats are wired from the factory. Access is mostly thru cable troughs. Parallel lines causes the problem of induction.

We create a lot of our own problems by tying wires neatly in bundles. I am guilty.

Originally Posted by IBNFSHN

I use to know that. Completely forgot how handy an old transitor radio was.

Me too. My neighbor (a retired ag teacher) was troubleshooting his truck radio the other day.

Thought I would mention this as it seems to be a lost art.

The AM radio works best when dialed between stations. No Limbos.

This is a great tool for finding shorts in most any kind of wiring. When you move the wire that is shorting, sparks from the short generate RF which the radio sees as static. Very useful for trailer shorts.