A month or two ago my public SDR servers were hit with some nasty noise. At first I thought it was builders next door who always leave tools plugged in. Then the complaints started...

Yesterday (April 29th, 2025), with the help of Tim M0AFJ I located the source of the noise, it was coming from somewhere in my SDR server setup.

Today I found the cause. The power supply for a USB hub had gone 'wonky', generating lots of noise which was radiated by the devices attached to the hub, such as 2 x Airspy Discovery, Perseus, ELAD S1 and S2, NetSDR.

This is not the first time I've had a PSU on these hubs go bad, so I replaced the hub with a good semi-commercial Exsys hub which was sitting in the cupboard, and now the problem is solved.