External antenna using existing CB mount on RV

doncant

I am about to purchase the Novatel 640 and want to install an external antenna on my RV. The mirror mount won't work for me (too wide for the supplied mount). I was thinking I might substitute a shorty antenna for my existing CB antenna (which I hardly use anymore). It should screw neatly into the existing roof mount. I have no idea if the existing cable is adequate.

Advice appreciated.
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Don Canty

Scott · Posted: Thu Nov 16, 2006 5:57 pm Post subject:

Our 18-inch Shorty RV Through-Roof comes with 13.5 feet of RG-58U attached and the adapter cable of your chosing to mate up with your EVDO card.

If you already have RG-58U (or better) fed through your exterior walls or roof, you could cut back and re-terminate the cable attached to the antenna and then tie into the existing feed. You just want to make sure any external RF connections are weatherized, and that the end of the inside cable is adapted to mate with the 18-inch adapter cable that will connect to your EVDO card. The added connection and adapter shouldn't increase loss that much.

For flange mounting, the 7-inch all-thread rod could be left off of the Shorty RV Antenna. The threaded base on the coil spring would then simply drop through a 7/16-inch hole and could be secured with a washer and size 7/16-20 nut (not included). Same thing for any thin sheet metal roofs or environmental enclosures (industrial uses). You don't really need the extra 7-inch all-thread rod unless dropping through thick, insulated roofs.

This also brings you down to the shortest possible working length on that antenna (16 and 1/2 inches), still retains the spring base for low-speed collisions, PLUS it has the ground plane spires.

While all other similar-length Wilson antennas utilize the same basic tuned antenna elements, they don't have the ground plane built-in. So this is a cool way to lower your minimum height restriction AND be able to mount on or over fiberglass or composite roofs.