I have trackeled a noise out of a Goodmans Freeview box plugin PSU. These are only just on the market.
The QRM was a screeming noise on 4meters, with a similar noise detected by my QRM sniffer rx next to the device. There did not appear to be much on the mains lead it was plugged into.
The device is very small yet delivers quite a big output. It is equiped with a lump of Ferrite around the output lead (low volts output) but this at the staterlite box end. Whether this is to remove Rf into the sat box or not is open to speculation.
What is needed was another piece of Ferrite at the PSU end of the cable.
Two passes though a clip on and all is quiet.
The lead is about quarter lamda on 4 meters.
I have expressed the problem to Goodmans.
David G3PTU
