Topics

Interference


George Stein - NJ3H
 

This was also posted on the Console Forum as well.


Greetings,
 
I could sure use some help trying to identify as shown in the attached pictures.  This interference occurs in the 2 mhz, 7-10 mhz, and 16-20 mhz bands and to a minor amount elsewhere on HF.
 
I have had this problem before.  I have walked the neighborhood with a portable Sony SW receiver.  On house (3 away from me 250 feet) seems to have interference when I am in their yard.  The young guy basically refuses to help out.  I have talked to him in the past very nicely.  He won't even answer the door.
 
One picture is from SDR Console using my Elad S2.  The other picture is using the Perseus.  my antenna is a 1-meter diameter Wellbrook loop in my back yard.
 
I have shut down the power to the house at the panel board and used a powerpack to provide power to the necessary components. I still have the interference as indicated on the attached pictures.  I do have ferrites on the antenna cables and power cables.
 
Anyway, I really want to determine what is causing this interference.
 
Regards,
George, NJ3H
Redmond, Oregon USA


Mag loop Simon
 

Thats a typical smpsu..could be from anything..phone charger, led floodlight etc..

Try nulling out with the loop..
If that does not work buy/ make a phasing noise canceller..or move house to ship out at sea..

Good luck and welcome to 2020.


Gisle Vanem
 
Edited

Anyway, I really want to determine what is causing this interference.

A rather old Switch-mode power-supply since the switching frequency is so low.

I'm more lucky I guess since it's mostly above 17 MHz: [QRM at 17 MHz]

With a neighbour with a SMP of 310 kHz. Which is very common for mobile-phone chargers etc.
But also some SMP with lower switching frequencies in between. Nice!