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juno.com!spindrift
Date: Thu Oct 17 1996 - 16:55:41 EDT
On Wed, 16 Oct 1996 14:27:03 GMT Rick Emerson <rick-ssg.com> writes:
Sean Holland writes:
> >You will have to get an extension cable approximately $50.00, and
unless you wish >>to have the cable exposed will have the problem of
how to secure the cable inside >>the mast.
>I can't speak to the RL-9's cable set but most radars come with enough
>cable for an installation without going to a longer cable.
The cables for the LCD Radar's in question are not sufficiently long to
allow mounting on the mast and reach to the nav station unless one
navigates next to the mast, so this favors a pole mount.
>Having argued against a radar mast, I will say that if there is a need
>for an additional utility mast for a wind generator, gin pole for
>handling a large outboard engine, etc. then adding a radar antenna to
>the mix is less of a problem. Bear in mind, however, that all of the
>weight penalties associated with the added mast remain.
>
Our combination Radar/Wind Generator/Stern Light/Outboard motor hoist
pole cost $25.00 for materials and weighed 7 lbs. I found the weight
penalty to be insignificant, while the advantage of having the four items easily contained and mounted to be both useful and convenient.
>Fishing the cable through the mast wasn't a walk in the park but it was
>accomplished without dropping the spar.
A number of masts have internal halyards, and this usually precludes
simply fishing the cable through. It was quicker, cheaper, and more
convenient for me, to design, build and install the Radar pole, than it
would have been to pull the mast, buy and install the mast bracket, and
install the Radar up the Mast.
>Your point about keeping the antenna (and the bulk of the RF system,
>for that matter) off the stick in case it fails is well taken. A
>separate radar mast, however, adds still more windage, complexity
>(backing plates, etc.), and may have to go in a location not meant to
>take the loading imposed by the radar mast (which may mean added
>modifications to the transom skin).
On some vessels this might be a concern, but I found that placing the pole on the Hull to deck joint, (not usually a weak portion of ones boat),
resolved this without the requirement for backing plates, or excessively
loading the boat. The concerns for windage down low, is much less
significant than windage aloft, as the pole is located in an area of
turbulent flow, while a Radar aloft is exposed primarily to unrestricted
and higher velocity wind.
>The truth is there are no best answers, only different solutions which
>work best for individual boats and budgets.
My only point was that it was generally easier, more economical, allowed
better close in viewing, while having less windage and moment of
heeling, and did not require pulling the rig, when one installed the
Radar aft on a pole, as opposed to installing up the mast. In addition one might gain the advantage of other uses for the pole, as we did by
installing the Wind Generator and a Stern Light that was much higher and
more visible than our original one, on the same pole.
I believe that "Close in Viewing", is one of the least often considered
and most important capabilities of Radar. Mounting the antenna way up
the mast, defeats this important ability of the Radar, while not really
adding significant range.
Boats by their very nature represent each owners ideas and solutions for
the numerous options available.
Good Sailing,
73, NP2AU
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