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RVing message boards => PCs, Communications, Electronics => Topic started by: RVJeeper18 on October 11, 2018, 07:35:08 AM

Title: CB Radio Antenna Install?
Post by: RVJeeper18 on October 11, 2018, 07:35:08 AM
2017 Coachmen Leprechaun 317SA - Class C
Sorry - this has probably been addressed but my search skills are lacking...  Feel free to direct me to existing threads.

Want to install a CB and looking for simple install I can do myself. Have the CB radio and mount figured out but big question is where/how to mount antenna.

Looking for something as simple to install as possible, even if it doesn't look as slick/factory. Would rather not drill holes in the sides of the MH if I can help it.

BUT, at the same time want something that gives good reception and is tight/secure.

Any advice on mount and type/model of antenna appreciated.
Title: Re: CB Radio Antenna Install?
Post by: John From Detroit on October 11, 2018, 05:41:07 PM
There are photos of my CB antenna install... But I will describe

First the antenna. Mine is a Radio Shack NO GROUND PLANE I suggest a Firestick NO Ground Plane... basically the same antenna any truck stop should have 'em. IF there is a "LONG" and a "SHORT" version  longer is better

IT mounds on 1/2 of a West Coast Mirror Mount. this mount consists of two pieces of aluminum.  One is "L" shaped and the antenna mount is on that half. the other half is more or less flat (Both halves may have a "Bend" in 'em to clamp around the tube on the mirror)

I figured out at what point the tip of the antenna was like 1" HIGHER than the otherwise highest point on the RV and marked the spot then drilled a 5 hole pattern  4 Matching the Mirror mount (I mounted with lag bolts) and one in the middle for the coax.  Ran teh coax into the RV (or out you can do it either way but I put the factory connector on the outside) and seal the hole the coax comes out the "Tunnel" (the Where the mirror tube would go) and into the SO-239 connector on the antenna mount. IF your mount uses a bolt and ring terminal even better. Be sure to seal the coax and all exposed wire below the mount against moisture.. GOOP works well.

4 Lag bolts into the A Pillar

Coax runs down the pillar to under the dash then out to the radio

Antenna works fairly well (As well as can be expected) plus it's a "Bridge Stick" if it rubs aganst the underside of the bridge (approach very very slowly) Do not go there.
Title: Re: CB Radio Antenna Install?
Post by: Hanr3 on October 11, 2018, 09:54:22 PM
Firestick makes awesome products and they have a great website where you can learn the best option for your situation.

The BEST place to mount a CB antenna is dead center of the largest metal roof. Moving it forward or backward will increase reception in that direction.
Semi's use two antennas that are at least 8' apart and visible to each other, this creates the ground plane. This configuration works ok front to back but has limited reception out to either side.

Check out Firesticks website.
Title: Re: CB Radio Antenna Install?
Post by: HappyWanderer on October 11, 2018, 10:37:03 PM
Without drilling holes, you don't have a lot of options. A mirror mount is probably the best bet, but you'll need one with long enough bolts to straddle the wide arm on the mirror bracket. Use a piece of split loom to protect the cable, and perhaps a piece of rubber wrapped around the mirror arm to protect the paint.

As John said, the nice thing about the Firestik is no ground plane is required. To protect the antenna connector, use Scotch Super 33 electrical tape, starting on the cable and wrapping up to the connector (think of how shingles work on your roof). Apply ScotchKote and a second layer of tape after it dries. You'll have a weatheproof connection that will last forever.
Title: Re: CB Radio Antenna Install?
Post by: Larry N. on October 12, 2018, 07:13:22 AM
A mirror mount is probably the best bet, but you'll need one with long enough bolts to straddle the wide arm on the mirror bracket.

That's great for truck-style mirrors, but many coaches have bus-style mirrors, which wont accept that type of mount. My coach, and the previous ones) has a small rubber antenna mounted on the roof, but finding the coax connect under the dash is a headache, and I've not yet found it on this coach, so I'm using a Midland handheld for now -- works fine for close-in work on the road.
Title: Re: CB Radio Antenna Install?
Post by: HappyWanderer on October 12, 2018, 08:35:12 AM
The OP has a Class C, which doesn't lend itself to a lot of options.
Title: Re: CB Radio Antenna Install?
Post by: John From Detroit on October 12, 2018, 09:36:45 AM
For a class C depending on how long that firstick is I'd mount on the rear of the "House" centered again with the tip at 13'6" from the ground.

Mounting on the center of hte roof means you can only mount a limited aboutnt of antenna. If your vehicle is 12 foot high you can only mount an 18" crap-tenna.  since you really need to keep things below 13/6"

Also if the body is fiberglass. well then it really does not atter where you mount the antenna (Originally I had it stuck behind the couch inside my Class A).

Use of two antennas phased gives you.. Ideally, a figure 8 pattern favoring stations in front and to the rear.. THE Ideal pattern for driving on a freeway.

Title: Re: CB Radio Antenna Install?
Post by: HappyWanderer on October 12, 2018, 11:25:51 AM
Making something so simple most complicated. Mounting an antenna at a the rear of a motorhome will require at least 40 feet of cable, with the signal loss and installation hassle simply not worth the effort.

We're talking about a 4-watt radio good for a couple of miles. The KISS principle applies.
Title: Re: CB Radio Antenna Install?
Post by: SLOweather on December 04, 2018, 08:48:10 AM
I realize that this thread is a couple of months old, but I'll add my 2ȼ for the record.

Since we bought our Suncruiser back in '89, I have used marine antennas with great results. We had a marine grade CB antenna, and a marine VHF antenna which I connected to our first mobile phone, a VHF IMTS phone.

On this Sunstar, yesterday I installed a marine SiriusXM antenna.

Marine mounts usually have a handy layover mount for lowering the antenna for low clearance.

I understand the the OP is shy about drilling holes, which I am not. I use liberal amounts of Tacky Tape butyl rubber to seal my mounts, hardware, and cable entries, and Dicor lap sealant for the screw heads.

(The marine CB antenna came with the cable and connector preinstalled and there was a white rubber bottle stopper with a hole in it to plug the cable hole. I used that >25 years ago and it worked fine.)

One other trick that wasn't addressed and works for many kinds of antennas and can be hole free. Glue down a piece of galvanized steel plate on the roof with something like lap sealant or Lexel and stick a mag mount antenna to that. A 4x4 junction box cover from the hardware store works. Depending on the ground plane needs of the antenna, you might need something bigger from a sheet metal shop.

I have 2 on this Suncruiser, one for the GlobalStar phone antenna, and one for a cellular router antenna and GPS antenna. I stuck them down with Tacky Tape and screws, but an adhesive by itself would work as well. Rather than drill a hole, run the cable through the door opening.

Or put a mag mount antenna on the hood and run the cable through the firewall.

For cable entries, I drill a hole and use Winegard satellite cable cover plates. I've seen them in 2, 3 and 4 cable versions, and have one of each on the Sunstar.
Title: Re: CB Radio Antenna Install?
Post by: John From Detroit on December 04, 2018, 05:28:24 PM
I will list considerations and what I did on my class A
Max height of unit INCLUDING antenna should be limited to 13.6 though you can go a bit higher with the antenna. beware low bridges.. Mine is lower

Aluminum is a good ground plane if the coach is Aluminum.  Fiberglass is NOT so if it is fiberglass use an NGP (No Ground Plane) antenna like a FIrestick

Up to a point (roughly 9 feet) longer is better for the antenna.. BUT.. that aluminum body is not a friend to a 'Bumper mounted" 9' foot antenna

Best location is top dead center of roof.. but again you likely can't put a long antenna there.

So what did I do (Fiberglass Class A) and what would I recommend for you.

I have a NGP (No ground plane) antenna a vintage Radio Shack. I mounted it on a 'Mirror Mount" this is an "L" shaped bracket designed to clamp onto the arm of a "West Coast" style Semi Truck mirror. but I lagged it into the "A" pillar instead of using both halves of the mirror mount.  Coax comes out a hole behind the mount into the channel for the mirror arm and around to the Coax Conneciton.  I sealed the hole as well.

Tip of antenna is about 1" higher than top most point on RV so it doubles as a "Bridge Stick".

IN your case I'd likely mount on the "Cab over" portion  IF Fiberblass.  If aluminum I have no suggestions.