| VHF Radio and Antenna Installation: Antenna Installation |
From "Shipshape Boating"
episode DSSB-104 |
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In this segment, host John Greviskis installs the antenna for the VHF radio. Materials: T-Top aluminum structure
Radio box (made one on episode 103)
VHF radio
Antenna
Safety glasses
Short pencil
90-degree drill
4 self-tapping screws
Countersink bits
Marine-grade silicone
Short snubbed #2 Phillips screwdriver
Ground block and a terminal block
14-gauge 2-strand copper tinned wire
4 stainless steal machine screws
Tef-gel
Electricians fish
Black electrical tape
Razor knife
Ring connector (1/4")
Ring connector (3/8")
Heat gun
Flat washers
Ny-lock nuts
PL-259 connector
Proper amp fuse - Now that the radio box is ready, you can take it and set it underneath the shade of the T-top (figure A).
- Have someone hold the radio box in position as you mark the mounting holes with a grease pencil exactly where you want the holes to be. You can use the brackets as a template to mark the mounting holes.
- Drill the holes through the radio box so you can bolt the box into place permanently. To avoid corrosion, be sure to use stainless steel hardware. Also, it's best to coat the hardware with a ground-up Teflon gel (called "tef-gel" -- which helps to isolate two metals that are attached together).
- Cut a hole into the hollow anodized aluminum tubing that is part of the T-top frame.
- Place the hardware down through the top of the drilled hole, and come in with a fender washer and nylon nuts and secure. The radio box should now be centered and secured (figure B) under the T-top.
Selecting the Antenna There are a variety of antennas on the market. You can go inexpensive (from around $29) with a fiberglass model that houses a thin copper wire called "the element," which is what gives the VHF radio the ability to broadcast and receive signals. If you want a bit more range out on the water, you should consider a better grade antenna. A $40 model will have a thicker element for more power. The higher-end models (anywhere from $80 on up) will have a copper tube inside instead of a thin wire, which gives superb range. At the end of the antenna is a coaxial cable (figure C), and it needs to run from an attaching point into the radio box. That attachment point is a ratcheted rail mount (figure D), and the antenna is screwed onto the end of it. Be sure to unscrew the bolts on the bottom of the rail mount and apply some tef-gel on the threads and clamp into place. - You want to mount the antenna base right on the top of the T-top outer rail port side of the rail -- about a third away from the front (figure E). One of the great advantages of this style antenna mount is that it can be attached any type of railing or piping you may have on your boat. The mount also allows you to quickly lower or ratchet the antenna in any direction you desire. In fact, it will even lay down flat in case you come upon high winds.
- Now it's time to fish the coaxial cable through the grommets in the radio box, cut it to length and use a PL-259 connectors (figure F). In the old days, you would have to solder the connections onto the coaxial cable, but today you can use a "quick connect" (be sure to get the PL-259 quick connect, which is gold plated).
- Crimp the end of the quick connect onto the coaxial cable, thread it into place and you're set.
- Attach the connector into the back of the VHF radio (figure G).
- Now, clamp on the VHF antenna base to the frame of the T-Top. It simply clamps on with the use of four stainless steel machine screws.
- Slide the coaxial antenna cable down through the base and coat the threads on the eight-foot long antenna with the ground up Teflon.
In the last segment, you'll learn how to power up the VHF radio.
RESOURCES :
VHS Marine Radio Handbook
Model: 1892216477
Author: Mike Whitehead
(January, 2003)
To order this title from Amazon, click here.
Bristol Fashions Publications
Communications at Sea
Model: 1574091611
Author: Mike Harris
(May, 2003)
To order this title from Amazon, click here.
Sheridan House
The Motorboat Electrical and Electronics Manual
Model: 1574091492
Author: John C. Payne
Order this book from Amazon.com.
Sheridan House
Electronics Aboard
Model: 189221640X
Author: Stephen J. Fishman
(September, 2002)
To order this title from Amazon, click here.
Bristol Fashion Publications
The Marine Electrical and Electronics Bible
Model: 1574090607
Author: John C. Payne
(October, 1998)
To order this title from Amazon, click here.
Grafton Books
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