It has been suggested that a faraday cage over the nav lights at the masthead might fix the interference with the VHF. I've just been up the mast on the climber to wrap the nav light fitting completely in two layers of alfoil as a test run and it doesn't make any difference. Damn! And now I have to go up again to take it off but I'll take the silicone spray up with me and squirt the mainsail track on the way down.
I have also been told that LED's are on/off devices and the resulting frequency might be the problem. On to Google when I get down from the mast but if anyone has any suggestions, please toss them this way via the gust book. It must have been fixed somewhere sometime before today...
