Hi,
I had a similar problem with a wall SMPS, (switching mode power supply).
I used a single 240/31, with 7 or 8 turns of the power cord, wrapped
such that the ferrite was as close to the power supply as I could get it.
The problem ended. I also tried 5 snap on Mix31 ferrites, and the
problem persisted... The blocking ability for RFI goes up dramatically
when you wrap turns on a ferrite.
See:
http://k9yc.com/2018Cookbook.pdf
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources
On 4/22/22 07:20, Mike Fatchett wrote:
This morning the noise is back. Same light. Tried a snap on on the
other side of the controller which did not work.
W0MU
On 4/21/2022 11:36 PM, Mike Fatchett wrote:
I ran into a new noise here. It started on 15m through 40m on
antennas close to the house. The noise seemed to come on in the late
afternoon or evening. It was very evident when I turned the antenna
toward the house.
The noise almost sounded like an am signal in the noise. KOA radio
with 50k watts is about 5 miles away so they can get into lots of
things. There were distinct mounds about every 20kcs and an overall
hash on the flex that took the noise floor from -120 to around -110.
The only thing in the house that I could think of are my fish tank
lights. I have 3 tanks all with the same light or similar style and
design. I pulled the plug and the noise is gone. I narrowed it down
to the tank that is in the shack.
The brand is Hygger and I bought it from Amazon. It is an led light
bar. I wrapped a number of turns through a snap on ferrite and
plugged it back in. So far so good! The cord is a wall wart that
plugs into the control unit which turns the light on, timer etc. 42
watts 215 led bulbs.
I can attempt to detail this further with recordings and screen shots
if needed.
I just thought I would pass this along.
Mike W0MU
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