[Elecraft] Fwd: OT Mystery QRM Help (Video)

[Bob McGraw K4TAX]

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, ac5p at 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 
> <rmcgraw at 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.
> >
>
>
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