Sorry for the delay in replying - had no internet
in the remore Bahamas
for a few weeks now.
John A : The tuner and the inverter
are not within range of each other, but the radio
itself and the inverter are in the same locker within about 18 in of each other (I thought it was a good idea at the time - doh!).
I've done a bit more fiddling and have systematically removed and replaced the grounds on the OPC cable at one end then the other, the RF ground onto the radio and tried adding a foil from the radio chassis to the AC ground on the AC panel. All about the same result, still getting the inverter turning on.
Also to eliminate this as a source of problems, I rerouted the power cables
from the DC panel (was connected where the 3/0 cables
come from the battery
bank) to within 18 in of the batteries, actually at the 300A fuse I don't really want to make a direct connection to the battery
I also tried putting foil between the case of the inverter and the RF ground (keel bolts), but no joy.
Still no joy, I'm starting to think this is just an issue with the Xantrex inverters, but I'm still surprised no one else has seen this.