Charlie,

Icom is incorrect in their documentation showing both ends of the tuner control cable to be grounded. it's unnecessary and potentially problematic. this has been discussed at length, though it's not much of an issue. many of these measures were borne from minimizing the LED's on Hallberg-Rassy's from blinking. I suspect your Malo might have the same Christmas tree lighting issue, though the cures are not really worth the effort, and besides, the blinking lights can be entertaining!

I didn't mention ferrites, but as you know, they should be liberally applied. important at the Autopilot DC supply, and I also use them on the fluxgate cabling, as noise can feed back into the fluxgate circuitry and cause errors. actually, I use them everywhere! I do recommend you treat your supply and RF grounds separately, as much as possible. it's true that the M-802 is an unbalanced output, but once it goes to the tuner (line-isolated) it's isolated and there are good reasons to keep them separate. as far as grounding, I think we've had this conversation before about antenna grounds. I've found that a single point connection to a thru-hull is generally the best you can do. in summary, most of the grounding plate (sintered bronze) and ground plane schemes are not as effective as a counterpoise as thought. this can be argued till exhaustion, and some schemes are better than others. the reality is that our watery surroundings help considerably, and the grounding is less critical in most marine applications. you should string a G5RV (or other balanced) antenna up the mast for comparison against your backstay.

I was surprised to find that my AC charger for my computer was the main noise source at the dock and easily corrected. Solar controllers are notoriously noisy as are most DC-DC convertors. Seatalk components are not shielded and you should apply ferrites on the wind instrumentation cable that ventures up the mast. as you have found, selectively disconnecting components can be enlightening, and more than one cell-phone charger has been tossed overboard for the sake of amateur radio communications!

I am on the 3870 Khz net every morning and you should check in sometime and say hello. my isolated stay antennna works quite well, garnering great signal reports. one of the benefits of a sailing radio station, is that you can find essentially zero noise locations. on Stuart Island (Reid Harbor) where there is no electricity from the mainland, many times there is an indiscernible noise-floor, which as you mentioned, makes a real difference in receiving weak signals. I've been anchored and had arm-chair copy with stations in Italy, Japan, and Patagonia with 100 watts and a little wire reaching up to the top of my mast. how fun!

I'd be happy to assist with any on-air antenna tests you might find of value.

NF7Z, daniel