Local interference in my shop - any ideas?

1

Hi all, please take a look at this image. Note I’m sweeping up to 100KHz and have a whip antenna connected directly to the + analyzer input (I have a 401 but it’s not related to that). The - input has a shorting plug.

Starting at 50KHz and up to almost 100KHz there are three spikes, two narrow, one wider. These exist in my environment and are always there. I’ve tried A LOT of things to see if I can find the source without luck. Do any of you have thoughts on what this might be?

Signed,
Puzzled

residential noise
residential noise962×656 118 KB

2

Answering myself - I found a noisy wall wart and the 2 sharp spikes are gone. But the wider one between 60 and 70KHz is still there.

residential noise 2
residential noise 2958×649 115 KB

3

Probably some other cheap non-compliant switch-mode supply radiating into the mains wiring. For instance LED lighting can be a source of this.