Ground plane required on a fiberglass boat?

SWD

Petty Officer 1st Class
Joined
Mar 1, 2011
Messages
284
Have a Celebrity Calais that I wish to install a UHF radio so that we can communicate back to the RV. Do I need a ground plane of some sort as this install is on fiberglass and not metal?
 

Thalasso

Commander
Joined
Jan 18, 2011
Messages
2,879
Re: Ground plane required on a fiberglass boat?

Most mobile antennas do not require a ground plane.

All you're gonna need is a No-Ground Plane antenna kit (Firestick makes good ones, as does Wilson). Motorhomes, boats, most 18-wheelers, they don't have metal bodies anymore, and No-Ground Plane antennas work well

Do J-Pole antennas need to be grounded? | KB9VBR J-Pole Antennas

J-Pole antennas are half wave antennas by design. Actually they are a half wave antenna sitting on top of a quarter wave matching section. One great advantage of a half wave antenna that it doesn’t require any special grounding or a ground plane to operate. That’s why you’ll find half wave antennas mounted in difficult antenna situations, like on a boat or a vehicle roof made out of fiberglass.
As for the second half of the question: yes the J-Pole should be grounded. But instead of an RF ground, the antenna should have an electrical ground to protect it in case of a lightning strike. An electrical ground doesn’t enhance the RF radiation of the antenna, but it is an important safety feature on any installation. A simple electrical ground would consist of a ground line from the antenna either bonded to the tower system or run to a buried ground rod.

The lack of a groundplane makes it easy to mount this antenna just about anywhere. You could put it in your attic, on a chimney or a temporary mast. In fact the lack of a groundplane makes the J-Pole a great choice as an emergency or field antenna since there is less parts you need to assemble in deploying the antenna.
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Re: Ground plane required on a fiberglass boat?

When your mounting an antenna on a boat, your not going to get a better ground plain than the lake etc that your floating in.
 

jhebert

Ensign
Joined
Jul 24, 2005
Messages
903
Re: Ground plane required on a fiberglass boat?

Have a Celebrity Calais that I wish to install a UHF radio so that we can communicate back to the RV. Do I need a ground plane of some sort as this install is on fiberglass and not metal?

The need for a metal ground plane in the vicinity of an antenna depends entirely on how the antenna was engineered. Some antennas are designed for use above a large flat metal surface like an automobile roof, and other antennas are designed to be mounted on non-conductive surfaces. Since you give no information about the antenna you are asking about, it is impossible to answer your question.

I am glad to hear you are installing a UHF radio. You cannot use a VHF Marine Band radio to communicate from your boat to your RV on shore. You would need a shore station license in the Marine Radio service, and you cannot get one except in special cases.
 

jhebert

Ensign
Joined
Jul 24, 2005
Messages
903
Re: Ground plane required on a fiberglass boat?

When your mounting an antenna on a boat, your not going to get a better ground plain than the lake etc that your floating in.

Most lakes are fresh water, and fresh water is very non-conductive. You cannot get a worse ground plane than fresh water.
 
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