I have installed an Icom M801E on my Santorin. My setting: The Transceiver is at the navigation table, the tuner in the Lazarette, the ground plate in the skeg plus a whip antenna.
The Transceiver is connected with the tuner via control cable and an antenna cable.
The control cable has on both ends small earthing wires, which connect to the Transceiver earthing point resp. to the tuner earthing point.
The tuner is connected/earthed to copper piece in the Lazarett.
Have you additionally earthed the Transceiver with a yellow/green cable? If yes, where does it go to? To the ground plate / the copper in the Lazarette which goes to the ground plate in the skeg? Or, if yes, does it go to the tuner?
Thanks for Your advice.
Best - Daniel
SY HEUREKA (SN 64), Kuşadası (Turkey)