RF Ground on Foam Core Hull

[FuzzyFeat]

I am installing my ham rig on my 35 foot cat. The hull construction is PVC foam core glass composite. I have heard of folks running the ground inside the hull below the waterline on all glass boats with good results, but not on composites. Any experience? Comments?

Thanks - Philip

[sailvayu]

Cored boats are composite boats just with a core lol. I have never heard of a cored boat being any different as far as RF grounds go. Just follow the advice about radials and a good ground you can find here and life should be good

Fair Winds

[GordMay]

Originally Posted by sailvayu

Cored boats are composite boats just with a core lol. I have never heard of a cored boat being any different as far as RF grounds go. Just follow the advice about radials and a good ground you can find here and life should be good
Fair Winds

I'll certainly defer to our radio Gurus, like Bill et al, but suspect that Philip’s concerns may have some basis in fact - a CORED composite may present significant differences with a solid laminate, in regards capacitive coupling.

[btrayfors]

As has been stated hundreds of times now on this and other Boards, there are lots of effective ways to implement a good RF ground.

Gord may well be correct re: coupling differences in cored hulls but, happily, it really doesn't matter. You DO NOT have to couple to seawater, or even connect directly to it.

However, for static bleedoff and for reducing noise it is generally good practice to at least run a short ground strap from the tuner ground lug to the nearest bronze thru-hull. If you don't have any, what about s/s rudder posts?

S/S rubrails, toerails, pushpit/lifeline/pulpit complexes, bit radar arches, etc., etc., all work well.

Radials will work just fine. Elevated radials work even better than burying them in the bilge. Basically, just run 'em as best you can and, wherever possible, use 1/4 wavelengths of insulated wire for the bands of interest.

There's even a commercial product being sold on eBay which is a shortened RF ground; just lay it around the bilge. Haven't tried it myself, but there's no reason it shouldn't work. I've done something similar as an experiment and thought about a marketable product, but just haven't got around to it :-) My experimental ground worked just fine, though.

The single strap to a thruhull will work OK all by itself. Radials will likely improve both tuning ease and radiated power.

Bill
WA6CCA