question

I would say the likeliest source of RF getting into the system is long communication cabling from the Cerbo to your MultiPlus, MMPT to Cerbo, etc. The first thing I would try is to put chokes around these wires to keep RF off of them. I’d probably put two chokes minimum, one near each end of the cable (they can act at the device without the added impedance of the cabling).

Incidentally, the Cerbo display comes with two chokes for the HDMI cable (this is, I’m pretty sure, in order to meet CE because of radiated emissions from the cable) and you should make sure these are installed. Put chokes on all the temperature probes, communication cables, voltage measurement wires, etc. if that doesn’t help, you could also add to the DC and maybe the AC lines, but I suspect it’s coming in on the communication lines.

Remember, the choke impedance at the frequency of interest is key so be sure to get a choke that works well at HF (18MHz in particular). A amateur radio retailer may have someone with enough knowledge to suggest the correct choke. If not, just look at the choke data sheet. —N5AC

I've got the same thing happening, getting Error 4 and Error 14 on the Multiplus when Transmitting 10Mhz on my Ham. Multiplus only resets when the Comms cable is connected to the Cerbo. I've got 2 Clip on Chokes on the Cerbo end, and one Toroid with 5 turns, also 1 Choke on the Multiplus end.

All the cables coming into the Cerbo have at least one Ferrite Bead on them, so far this hasn't stopped it, wondering if I just keep adding ferrites to the Comms cable. - M0XIO