A recently installed PV solar panel inverter is causing QRM on HF through 6m. The installation is approx 100 yards from my house and comprises PV panels on a roof connected by a run of roughly 60 feet of cable to an inverter located in a garage. The inverter is a 4KW SolarRiver 4000TL-D by Samil Power (http://www.samilpower.com
The interference presents itself as multiple carriers spaced 20 KHz apart across 80m, 10m and 6m. The signal level is -80 dBm on 80m (around S7 to S8), it is less strong on 10m and 6m. The carriers are relatively clean and vary in amplitude over a period of around one second. They are within a few Hz of 3500, 3520, 3540, etc.
I have tried fitting several TDK ferrite clip on chokes to both the mains and PV panel side of the inverter, unfortunately without making much difference. When the owner turned off the PV isolators the interference stopped, it is also not present after sunset.
Has anyone had experience of fixing the interference from one of these units?