Long ago, I was asked by a police officer friend to carry my portable HF
receiver by a building that they believed housed a stolen mini-computer. They
hoped that the character/rhythm of the RFI would match that of another
identical machine running the same OS. I did, but did not hear the noise they
were hoping for.
They were both disappointed and relieved since the next hurdle would have been
to establish the validity of the search since they didn't have enough PC
(probable cause) to obtain a warrant. This was back in the days when, in
California, warrant-less searches utilizing sensors more sensitive than human
senses (ie, drug sniffing dogs) were at risk of being thrown out of court.-Mike-
From: jimlux <jimlux@earthlink.net>
To: Grant Saviers <grants2@pacbell.net>; Ray Benny <rayn6vr@cableone.net>;
rfi@contesting.com; towertalk@contesting.com
Sent: Monday, May 9, 2016 9:43 AM
Subject: Re: [TowerTalk] [Bulk] How far does RFI travel?
They are plenty interested in busting grow operations. It's more about whether RFI is probable cause for a search warrant. It is not. You could get the FCC to send them a letter, maybe, but RFI is not a state law issue ( i think its good thing that federal law preempts state and local for RF)
Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone-------- Original message
--------From: Grant Saviers <grants2@pacbell.net> Date: 5/9/2016 7:32 AM (GMT-08:00) To: Ray
Benny <rayn6vr@cableone.net>, rfi@contesting.com, towertalk@contesting.com Subject: Re:
[TowerTalk] [Bulk] How far does RFI travel?
One thing I noticed when driving around with a PC+ USB spectrum analyzer
to find a new QTH, was how much quieter neighborhoods with in ground
utilities were from those with the old "poles and pigs" distribution
systems. Another observation was that big HV transmission systems were
quieter than expected when a few hundred yards from them. My conclusion
is the buried systems shield and choke the rf, just as happens with
buried coax. IMO, much of the rf trash we hear is generated by bad
devices and then radiated from pole systems. 60 acres NW of me were
recently developed, 20 homes on 2 acre lots plus open space and
underground utilities and so far so good. A plasma TV SW from me is an
S4 problem, but I haven't tracked it down. Hopefully, the new
subdivison near you will be all buried.
Several local hams here are seriously affected S9+ all bands by large
grow lights for recreational substances that are clearly not FCC
compliant re radiated and conducted emissions. The distance can be
significant - 1/4 mile or more. Most are probably illegal but of no
interest to law enforcement given trends of the new laws. The FCC
either "doesn't have the resources" or "won't investigate where illegal
activity may be happening without law enforcement present". A perfect
Catch22. In the past, when growing was clearly illegal, law enforcement
used AM radios to find the grow sites.
Grant KZ1W
Redmond, WA
On 5/9/2016 0:21 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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk