SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Electronics (http://www.sailnet.com/forums/electronics/)
-   -   VHF antenna for trailer sailor (http://www.sailnet.com/forums/electronics/56523-vhf-antenna-trailer-sailor.html)

macsailor 07-25-2009 09:59 PM

VHF antenna for trailer sailor
 
I used a mast mount 3 dB VHF antenna on my last sailboat but found it was prone to a lot of wear and tear on a trailer sailor. On my new boat I'm thinking about using an 8' 6 dB antenna mounted on the pushpit with a swivel mount so it can be just turned horizontal for trailering. I think it will eliminate any connectors between the antenna and radio so should make it more reliable. My concern is the effect on transmission range. Does anyone have any experience with this setup on a sailboat ?
The antenna I'm looking at is,
Shakespeare Marine Antennas Specifications: Centennial 5101 VHF Marine Band
Any suggestions or ideas appreciated, Bob

btrayfors 07-26-2009 07:06 AM

Bob,

IMHO, an 8' antenna is too large for a small trailer-sailer boat. And, it won't buy you much more in range over the standard 3db antenna.

VHF range is determined principally by height above the water, as you imply with your question. Many find that a stern-rail mounted VHF antenna is adequate for their purposes, i.e., talking with other boats they can see and with transmissions over distances up to about 5 miles or so. If the other station's antenna is high, distance potential is increased. Power helps somewhat, too. That's why you can easily copy USCG and WX broadcasts with a handheld radio over pretty long distances.

If you're really in need of communication over longer distances, then you've little choice but to rig an antenna at the top of the mast. Again, a 3db antenna is most appropriate, because healing will greatly reduce the distance potential of more "powerful" antennas, which have a narrower vertical transmission pattern.

Bill

NautiG 07-26-2009 09:52 PM

I have a stern mounted vhf antenna. Not sure of the specs, but it's one of those fiberglass jobs you see for about $50.

Length of cable and number of coax connections can degrade transmission strength. And having an antenna atop the mast can be a problem too. I don't like to go aloft too often for maintenance, but as a trailer sailor you don't have that issue. But as a safety issue, it would be a bummer to be dismasted and have no vhf.

My vhf works very well and I've easily conversed with the CG 20 miles offshore, but as Bill says their antennas are pretty high up.

Scott
Gemini Catamaran Split Decision

BlueWaterMD 07-26-2009 10:04 PM

Where do you sail? If you are a trailer sailor, and sail primarily in fairly protected inland & coastal waters, could you get away with a handheld. It works for me, but my sailing is confined to the bay. I am never out of sight of land, and always have other boats within eyesight. If you don't venture offshore, it may be a cheap and easy fix.

That being said, there is no reason why an 8ft antenna wouldn't work on your boat. Small power boats from around 17+ feet are regularly rigged with them. My old 21' fishing boat had one, and it worked great. The biggest downside is that you have an 8' antenna mounted in or near your cockpit.

capttb 07-26-2009 10:09 PM

I've used the 5 foot "Lift and Lay" type ant. on small powerboats with good results in coastal environments, they are pretty tough and they sell them here.
SHAKESPEARE VHF 5FT 420 3DB Shop.Sailnet.com - sailing resources, shopping, sail, blogs

macsailor 07-26-2009 10:15 PM

I have a handheld
 
I use a handheld at the helm but like to have a 25 watt VHF on board. I find the range shy on the handheld. I sail all over, Lake Ontario, North Channel, Florida in the winter. The old boat with the 3 dB antenna mast mounted antenna worked OK on the top of the mast but the connectors can not be waterproofed because they have to opened all the time. When trailering the coax connectors are exposed to lots of water. I use a cap on the deck fitting but the connectors at each end on the mast are subject to water ingress into the connector and coax cable. I think these big whip antennas work for power boats so why not use one on a sailboat ?


All times are GMT -4. The time now is 03:15 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012