Usually electrical noise is very broad band in nature. I use the MFJ
unit to find the general direction, triangulate to an area, and then
using a 24" reflector type microphone, equipped with a high gain audio
amp and headphones, go "listening to poles". {Yea the neighbors think
I'm crazy, but so what.} You can actually hear the arcing at connectors
for conductors, ground arcing or insulators arcing. I've even stood on
the ground with the crew from the power company and identified the exact
connector which is loose. Another handy item is an infrared
thermometer. A hot spot is likely a problem spot. This works to scan
ones breaker panel as well.
If the noise is inside a building or house, proceed with caution. Dogs
bite and occupants may shoot first.
If the noise is from a device oscillating this is more frequency
selective and a bit more of a challenge to find and isolate.
73
Bob, K4TAX
On 1/23/2016 4:29 PM, a...@sbcglobal.net wrote:
Yes, but David says, "only occurs on 20M", so this may not hear it at
135MHz? Need portable like KX3 and small mag loop tuned to 20M.
On Saturday, January 23, 2016 2:14 PM, Bob McGraw K4TAX
<rmcg...@blomand.net> wrote:
If one is serious about finding noise, I've found this item to go a long
way in identifying down to the building or site from which it
originates. It takes a bit of practice and time to triangulate but does
work well. I'm sure there's other equipment and methods available as
well.
http://www.mfjenterprises.com/Product.php?productid=MFJ-856
This is always a good item for a club to have and own for its members.
73
Bob, K4TAX
On 1/23/2016 1:06 PM, David Ahrendts wrote:
> A bit more: I watched this mystery QRM pretty closely for an hour
Friday evening as 20 meters closed for the day (by 6:30pm PST). The
cadence of this noise changed. It slowed. Then faded away with the
band. I’m scratching my brain to try think of a mechanical device that
would create that kind of rhythm. And as always as I check 20 meters
at 11am Saturday, there is no sign of the QRM.
> Will listen again late afternoon today. May experiment moving the
DB-11 around to see if it is directional.
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net <mailto:Elecraft@mailman.qth.net>
This list hosted by: http://www.qsl.net/
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to a...@sbcglobal.net <mailto:a...@sbcglobal.net>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
