Notices

3' and 4" VHF antenna range

Old 10-20-2011, 07:28 AM
  #1  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jun 2006
Location: Tampa, FL
Posts: 257
Default 3' and 4" VHF antenna range

In tried searching, but the terms are too common. Im looking to mount a VHF antenna to thentop of my t-top. I would of course want a 8', but I keep my boat fully covered and a 8' won't work under the cover. If i can make a 4' work, that what I would like to go with. What type of range can i expect to see? Thanks.
captainjz16 is offline  
Old 10-20-2011, 07:57 AM
  #2  
Senior Member
 
Join Date: Jan 2007
Location: Albemarle Sound Management Area
Posts: 6,217
Default

http://www.qsl.net/kd4sai/distance.html
Crabpot Man is offline  
Old 10-20-2011, 08:02 AM
  #3  
Senior Member
 
Join Date: Mar 2010
Location: Hopkinton MA
Posts: 842
Default

My boss went with a 4' on his new hard top. After his first offshore trip (25 miles) and not getting any response on the VHF he made the switch to an 8 footer. He has an extra sense of security now with the 8 footer. if you stay inshore you should be fine but they are not practical for offshore use.
Tuna Meltdown is offline  
Old 10-20-2011, 08:23 AM
  #4  
Senior MemberCaptains Club Member
 
bsmit24's Avatar
 
Join Date: Aug 2004
Location: Republic of West Florida
Posts: 17,695
Default

I know it has been posted previously but if you haven't read it might answer some of your questions http://continuouswave.com/whaler/ref...HFAntenna.html
bsmit24 is offline  
Old 10-20-2011, 05:18 PM
  #5  
Senior MemberCaptains Club MemberPLEDGER
 
Join Date: Feb 2004
Location: Atlanta, GA
Posts: 8,140
Default

There is no substitute for height if you are going offshore. That said, if you stay near shore, you can get away with a shorter one.

I'm using the Metz 3' SS and it works as well as the 4' Shakespeare that it replaced. Maybe a setup with the 3' SS on a 4' extension would be a compromise??
Parthery is offline  
Old 10-20-2011, 10:33 PM
  #6  
Senior MemberCaptains Club Member
 
Join Date: Feb 2003
Location: M.Vineyard, MA
Posts: 13,920
Default

Any reason why a good 8ft 6db antenna on a SS swing-down ratchet mount would not fit under the cover? Just too long?
TTaxi is offline  
Old 10-21-2011, 06:53 AM
  #7  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jun 2006
Location: Tampa, FL
Posts: 257
Default

Cover goes over the t-top and is pretty snug.
captainjz16 is offline  
Old 10-21-2011, 03:24 PM
  #8  
Senior Member
 
Join Date: Mar 2011
Location: Venice, FL
Posts: 1,901
Default

Consider an 8 footer mounted on a vertical support to your T-Top as high as you can and yet still fold down the antenna to prevent cover interference. That way you get optimum gain and decent Line of Sight. 3 to 4 footer if it doesn't interfere with cover but mounted up top should be almost as good as the former. Line of Sight and Gain are neck and neck for most influencing your range.
capecuddy is offline  
Old 10-22-2011, 12:27 PM
  #9  
Junior Member
 
Join Date: Jan 2008
Location: Jonesport USA
Posts: 13
Default

The difference in effective range, due to differences in antenna height (at least on a small boat), is negligible. As you're in a small boat, you'll want to be careful regards a given antenna's gain (expressed in deciBels or dB). Stay within the 0 dB to 3 dB range. Finally, make sure that your antenna is located no less than three or four feet from the radio itself. In my opinion, Morad makes the best marine antennas.
Herring Choker is offline  
Old 10-24-2011, 10:03 AM
  #10  
Senior MemberCaptains Club Member
 
Join Date: Mar 2001
Location: MD/DC & IRI - 05 Southport 26 Honda 225s
Posts: 3,914
Default

Roughly a mile or less difference in range per the calculation. You never know when that might matter. Mounted up high, it probably wont be significant. I had a 4' mounted on the gunnel of a smaller boat and found it sometimes was shielded by larger waves and lost the signal in a trough.
Frank007 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread