Making a Ground Plane for various antennas questions ? ? ?

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
nvrver

nvrver

Well-known member
Joined
Apr 15, 2009
Posts
907
Location
Fallon Nevada
Making a Ground Plane for various antennas questions

I my class C with cab-over entertainment center if I remove the big 26? CRT TV I have access to the underside of the front cap and fiberglass roof.  I would like to install a cellular antenna and 2 meter quarter wave ham antenna.  Would gluing a thin piece of metal under this part of the cap work for a ground plane?  The area for the metal is about 30? wide by  12-18? deep.  I know I can purchase antennas with built in ground plane, but I would like to use the antennas I already have.
TIA for any comments or suggestions.
Dick
 
Dick,

The only problem you might have is if your antennas require contact with the ground plane.  In that case you will have to drill holes for them - probably have to do that anyway.  :)

I have used aluminum foil and cemented it to the surface of the RV, worked fine as long as the cement held.  I have also used thin sheet aluminum the same way.  You should tie the ground plane to the vehicle ground also although this may be done with the coax, I don't prefer this method though.


Just a few quick thoughts.
 
I am curious as well.

I am going to install a Sirius Satellite Radio antenna soon.  I haven't been able to find a local installer who's eyes don't glaze over when I start asking about a ground plane.  Just use silicone to stick it on they tell me.

So, does anyone have any experience with using a ground plane on the inside of a fiberglass roof cap?
 
The Sirius antenna doesn't need a groundplane - it works fine hanging in mid-air.  So the installers are right when they say just stick it somewhere.

I found the center brace of my roof  vent was made out of steel, so I put my antenna there.  It doesn't interfere with the vent opening and closing and is high enough to see over the RV's roof.  My first thought was to glue the top of the antenna to the underside of the domed cover, but while I was getting ready to do that it firmly attached itself to the center brace, so I left it there.
 
hahaha .... I'm glad that the antenna firmly attaching itself worked out well.

Now I feel like the idiot for pressing the Sirius installers about a ground plane  :(.  I think I will still try to mount it somewhere on the fiberglass front cap of my MH.  It just seems easier to run the cable through one of the clearance lights, down one of the windshield pillars and over to the cockpit.

I will probably first try placing it inside the MH, against the fiberglass.  That would save routing the cable from outside to inside and sealing it up.  I'm hoping that I can find a place that is far enough from the clearance lights or any other metal on the outside of the MH.

Not needing to worry about a ground plane will make it much easier.  I have done some googling and found different opinions.  I found the Sirius website and printed install instructions confusing.  The antenna is magnetic, so they insist it must be mounted to metal.  It's good to know that it is only for mounting, not for a ground plane requirement.

Thanks for your help.

Sorry to the original poster, nvrver, for the hijack.  I honestly thought that I too would have to deal with a ground plane.
 
We installed a Sirius Radio antenna on the top of our motorhome (not the front cap).  My husband drilled a hole, ran the wire down through a cabinet and it works great.  He did use silicone.

Marsha~
 
Sirius (and XM) do need line of sight to the satellites - roof mounting is the best option.  If you mount it lower than the top of the roof the RV body will block the signal when you're heading away from the satellites.

XM has a pair of satellites in geosynchronous orbit over the equator, just like the satellite TV folks.  For now, Sirius is using a pair of satellites in high elliptical orbit that moves their satellites all over the sky but they are preparing to move away from that in favor of geosynchronous.
 
pixurit said:
I am curious as well.

I am going to install a Sirius Satellite Radio antenna soon.  I haven't been able to find a local installer who's eyes don't glaze over when I start asking about a ground plane.  Just use silicone to stick it on they tell me.

So, does anyone have any experience with using a ground plane on the inside of a fiberglass roof cap?
Click to expand...

There are several antenna designs that need no ground plane, or if they do need one about the size of a dime

The Sirius antenna is in the "Coin Size" category.. Thus the small plastic thingy has it all. 

A Dipole needs none.. A circular polarized antenna won't need one either

Only a vertical and then not if it's a dipole or other selected types.
 
You must log in or register to reply here.

Latest posts

Members online

Total: 985 (members: 8, guests: 977)

Forum statistics

Threads
131,981
Posts
1,388,590
Members
137,726
Latest member
CampMike2270
Back
Top Bottom