Some are worse than others.? The power supply for my laptop raises the noise level 1.5 S units on all the HF bands, but the one on my HD monitor completely wipes out the 20 meter band and no others.? The 12V 30A switching supply I was using for most of my equipment put out spikes every 70 KHZ on 40 meters and 15 meters, but was fairly clean everywhere else.? I could clearly see the interference using an SDR Play. I tried the ferrite? chokes with minimal success.? I found the information in this website to be helpful:?
Dan, W2DLC
