Kenneth Gresham wrote:
>
>I am looking for suggestions for routing antenna cables (nav, comm,
> and transponder) and 12 volt wiring from aft of baggage bay. This
> is a tri-gear and I think I would prefer going through the center
> tunnel but I do not know what problems this may present. I am
> installing the finger brakes so there is access through the top
> front of tunnel just below the panel. Would a conduit bonded to
> the floor work? Do I need to separate antenna cables from other
> wires, if so, by how far? I need to bond on top of fuselage and
> want to do all steps possible with it off.
I have most everything coming through the tri-gear's tunnel. My electrical
bundles
are clamped and tie-wrapped, or wrapped with spiral cut poly tubing - mostly
for neatness or where there's possible chafing. Any conduit here would serve
no purpose if there's enough access to string the wires. I provided this via
a large access panel on the fuselage bottom where the monowheel would be.
Running any antenna coax in a bundle with electrical wire is a problem because
of intimate contact with any wire carrying 14V supply, which will have assorted
noise on it for inductive pickup. The shield on these coax cables doesn't do
all we intuitively think it does, and least so in a fiberglass airplane because
the antenna end of the shield is floating in space. It is best to run antenna
coax by themselves. I used plastic, self-adhesive wire clips affixed to the
sides of the tunnel. Since the inner glass is not smooth, one can likely use
5-minute epoxy on the foam adhesive.
Regards,
Fred F.
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