[RFI] How far does RFI travel?

Jim Brown jim at audiosystemsgroup.com
Mon May 9 12:14:23 EDT 2016

As always, great advice. I'll expand on it only to help understanding.  
RFI is like any other radio transmitter connected to an antenna -- make 
RF current flow on a piece of wire and it will radiate. The more power 
and the better the antenna, the greater the strength of the radiated 
RF.  The antennas can be anything conductive connected to the source -- 
power supply conductors, audio cables, video cables, etc. Wires running 
down a wooden pole to "ground" power wiring are ANTENNAS, and will 
radiate any RF current that they carry, including arcing on the power 
system. Coax carrying video and/or internet signals are antennas, and 
will radiate RF trash generated by the equipment to which they are 
connected. Virtually everything connected to a power source (battery or 
AC power system) is a potential noise source, every piece of 
electronics, including microprocessors built into products like 
refrigerators, washing machines, dryers, etc.

73, Jim K9YC

On Mon,5/9/2016 8:50 AM, Frank N. Haas KB4T wrote:
> There is no definitive answer to this question. In just a few replies, you
> can see that RFI can travel great distances. There are an infinite number
> of combinations all of which result in a widely varying range.
> There is no way to predict if the new subdivision will raise your noise
> floor. It's likely but impossible to predict. The suggestion made to begin
> measuring and recording your current noise floor is a good one. As the
> subdivision grows you may see your noise floor come up.
> Check to see if the electrical utilities planned for the new subdivision
> will be overhead or underground. If underground, less noise is likely.
> Frank N. Haas KB4T
> Utility RFI Investigator

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