Power line noise can radiate over a long distance. Even underground can
radiate but usually this type of noise stops around 9 MHz. Touch on lights
and bad wall warts especially the flat switching types can cause terrible RFI
but it seldom goes beyond a block from your location.
Other things to look for are door bell transformers, all sorts of motors
especially fish tanks motors. Appliances but these only generate noise when in
use. I assume that there is no commercial stuff nearby.
I suggest you get one of the RFI books sold by ARRL or HRO as these are very
good.
Dave K4JRB
-----Original Message-----
>From: Patrick Greenlee <patrick_g@windstream.net>
>Sent: May 9, 2016 8:31 AM
>To: towertalk@contesting.com
>Subject: Re: [TowerTalk] How far does RFI travel?
>
>Of course there is no magic distance beyond which RFI hits a "Gardall
>Shield." Distance attenuates and at some point the level will go
>significantly below your natural noise floor (world wide lightning
>discharges etc.) Another answer is, "It depends." If you have some pot
>growers using industrial lighting instead of residential lighting then
>be prepared for lots of noise. Fairly recently there was a big flap
>over commercial/industrial lighting being sold at the big box stores
>being put into residential use. The RFI emissions of the residential
>grade lighting are much lower than the industrial which cause
>significant RFI problems.
>
>Patrick NJ5G
>
>
>On 5/9/2016 2:21 AM, Ray Benny wrote:
>> body {height: 100%; color:#000000; font-size:12pt; font-family:arial,
>> helvetica, sans-serif;}This may seem a strange question to ask and there
>> maybe many answers, so I will try to be specific as to what I am looking for.
>> A new subdivision is being built about 1/4 mile away, east and north east,
>> towards EU. The homes are custom build on 1 acre parcels. What I am trying
>> to find out: can I expect my noise level to go up as more homes are built?
>> I spend a lot of time on 160m. I have a RX 4SQ and 2 wire beverage, and I do
>> hear a number of small RFI noises in a number of directions from nearby
>> homes in my rural area. Most of the time they do not cause any long term
>> problems. My thought is that when new housing comes in, new and more
>> electronic gadgets will be inside that can generate more RFI.
>> I have done some RFI tracking, mostly electric fences and leaking/defective
>> power line hardware, but these sources are usually very distinctive and
>> usually easy to fine. Finding wall wart, LED, etc RFI is harder to find,
>> especially on someone else's property. Another way to ask my questions:
>> "Does this type of RFI noise typically radiate more than several hundred
>> feet"?
>> Any thoughts or experiences are welcome.
>> Tnx & 73,
>> Ray, N6VR
>> Chino Valley, AZ
>>
>
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