tailgate antenna mount & grounding strap

**ImaginaryFriend** · 03-02-2008, 07:55 PM

I want to put the cb antenna on the tailgate's spare carrier, and I know the mount needs to have a good ground. I also realize the tailgate isn't a very good grounding point.

Can I simply put a grounding strap on the inside of the tailgate to the tub/frame? (As long as the mount is grounded good to the carrier of course.) I'm thinking in the same area as the 3rd brake wiring to try and keep it clean looking.

I've read over and over to run a grounding strap from the mount to the frame, but that would be a lot of strap length running on the outside...ugly.

I'm guessing this should be fine, but some of this cb stuff is finicky it seems.

littlebrother · 03-02-2008, 08:06 PM

ground is ground the world around.

The bumper is grounded by way of the frame. So long as your ground point is good and clean when you mate your antenna to your Jeep all should be well. Double check your choice grounding spot with a volt-meter.

**ImaginaryFriend** · 03-03-2008, 10:28 AM

I figured as much. But from all the pictures I see, very few include a shot of the grounding strap.

I guess I'm just making sure I'm grounding it properly when mounting the antenna to the tailgate.

**Jerry Bransford** · 03-03-2008, 12:50 PM

Quote:

Originally Posted by littlebrother

ground is ground the world around.

The bumper is grounded by way of the frame. So long as your ground point is good and clean when you mate your antenna to your Jeep all should be well. Double check your choice grounding spot with a volt-meter.

Not really, there are common ordinary every-day grounds that are suitable for DC and most needs in general, but for an antenna, a standard DC ground can often be insufficient. An RF ground suitable for an antenna has more requirements than a simple DC ground, which is why braided ground straps are used to ground antenna mounts instead of just a standard piece of wire.

I'd probably connect a short length of braided ground strap strap between the tailgate and tub to give the antenna the best possible RF ground which will help insure it works as well and has as low of an SWR as possible.

**Scrambler82** · 03-03-2008, 02:42 PM

I'm with Jerry but I would add a strap to the Mount itself.

Go from the Mount to the tailgate then to the frame or directly from the mount to the frame.
Make sure to get to bare metal where the strap(s) will be attached and use External Tooth Lock Washers and a good Conductive Paste on all connections.

**ImaginaryFriend** · 03-03-2008, 06:50 PM

Quote:

Originally Posted by Jerry Bransford

...
I'd probably connect a short length of braided ground strap strap between the tailgate and tub to give the antenna the best possible RF ground which will help insure it works as well and has as low of an SWR as possible.

Yeah, my plan was to put a strap between the tailgate and the tub, just making sure I was thinking along the correct lines.

Quote:

Originally Posted by Scrambler82

I'm with Jerry but I would add a strap to the Mount itself.

Go from the Mount to the tailgate then to the frame or directly from the mount to the frame.
Make sure to get to bare metal where the strap(s) will be attached and use External Tooth Lock Washers and a good Conductive Paste on all connections.

If I attach the antenna mount with some tooth lock washers to the spare carrier, you think I still need a strap from the mount to the tailgate? And that's sort of what I was asking...running a strap from the mount all the way to the frame seems like a looong strap, and I haven't seen pics of anyone doing it that way (although maybe everyone isn't doing a ground like they should).

After you get to bare metal and attach everything, do you just paint over it to seal it all up?

I guess I'm trying to keep it looking clean and eliminate as much potential external rust areas as possible.

**ImaginaryFriend** · 03-03-2008, 07:48 PM

Alright, here's what I mean. All these tailgate mounts and no external grounding straps. I'm guessing they have a strap from the inside of the tailgate to the tub/frame?

http://www.jeepforum.com/forum/f20/anybody-have-cb-antenna-mounted-their-spare-tire-mount-493826/?highlight=antenna+mount

And what about this...
What if I put the angle iron (ant. mount) on the outermost tire carrier bolt, used a longer bolt that went all the way through to the inside of the tailgate (drilled through of course), and attached the bolt (inside tailgate) to a grounding strap to the frame/tub.

That way the mount has a good ground, but I can keep the outside looking clean.

**LoneJeeper** · 03-03-2008, 07:53 PM

hm. explain to me the 'grounding of the antenna' theory.

I've got a firestik mounted to the plastic floaters on my still-stock bumper holes... no extra grounding. I still transmit & receive, what am I missing out on?

**Jerry Bransford** · 03-03-2008, 08:34 PM

Quote:

Originally Posted by LoneJeeper

hm. explain to me the 'grounding of the antenna' theory.

I've got a firestik mounted to the plastic floaters on my still-stock bumper holes... no extra grounding. I still transmit & receive, what am I missing out on?

Reduced range of signal and, likely, a higher SWR than you could obtain with a better more suitable ground.

And for clarification, we're not talking about a better ground for the antenna, it's a better ground for the mounting base. The type of antenna we use on our Jeeps relies on the Jeep for half of the antenna's total effective length. In other words, think of the Jeep tub/body/frame as half of the antenna. Unless the mounting base is well connected to all that, the antenna won't work as well as it could.

**LoneJeeper** · 03-04-2008, 07:53 AM

So I enlarged a hole in my stock bumper and bolted the antenna through it. Should i polish up the steel around the hole for better ground, or would a strap to the frame make more sense?

Does radio shack tune CB's? I'm in a bit over my head with this radio-wavelength stuff.

**Jerry Bransford** · 03-04-2008, 01:02 PM

Quote:

Originally Posted by LoneJeeper

So I enlarged a hole in my stock bumper and bolted the antenna through it. Should i polish up the steel around the hole for better ground, or would a strap to the frame make more sense?

Does radio shack tune CB's? I'm in a bit over my head with this radio-wavelength stuff.

The bumper should provide a good enough electrical ground providing you got rid of all the paint between the bumper and mount so there's a good electrical connection between them.

While I'm sure that SOME Radio Shack stores have people working there that could tune an antenna, most no longer do. I have three RS stores in my area and not a one of them have people working there that have any sort of electrical/radio knowledge. I called all three RS stores a couple weeks ago asking if they had a particular but common kind of electrical switch in stock called a "single-pole double-throw" and I might as well been asking for the formula to Coca Cola. They are useless when it comes to anything more technical than selling flashlights or cell phones.

Instead, I'd look in the Yellow Pages for a CB or ham radio store, or a truckstop that sells CB equipment. Those kinds of stores will have someone that can help you and even tune your antenna. Or drive to Escondido and I'll tune it for you.

**LoneJeeper** · 03-05-2008, 08:24 AM

Jerry, as always, thanks for the help. You must get tired of answering stupid *** questions.

Here's what I run: Uniden pc-68 Elite. 20 ft. of coax. stud mount to bumper, firestik 5' antenna.

With my mount, like so:

is it the 'e' part that is receiving the ground? it doesn't seem like that would be optimal... it's also the underside of the inside of the bumper. Could I re-arrange the setup so that the 'a' part is receiving the ground?

Should I just do a simple ring terminal around the stud and ground it to the frame with a jumper?

**Jerry Bransford** · 03-05-2008, 11:01 AM

The A part is what the antenna screws into so you definitely don't want that part being grounded. It's the E part that requires the good ground connection. The D part is what insulates the A part from being shorted to ground so always make sure the D part is there, not broken, and centered in its hole so the antenna cannot short to ground.

usarmy0101 · 04-06-2008, 11:36 PM

can u put a ground wire inbetween the "below" and top of E.. i have this same set up and need to ground it

**Bigbob** · 04-07-2008, 08:33 AM

Quote:

Originally Posted by Jerry Bransford

While I'm sure that SOME Radio Shack stores have people working there that could tune an antenna, most no longer do. I have three RS stores in my area and not a one of them have people working there that have any sort of electrical/radio knowledge. I called all three RS stores a couple weeks ago asking if they had a particular but common kind of electrical switch in stock called a "single-pole double-throw" and I might as well been asking for the formula to Coca Cola. They are useless when it comes to anything more technical than selling flashlights or cell phones.

LOL Isn't that the truth! Back 30 years ago Radio Shack always had at least one person who could answer questions. Now they have the mentality of a fast food place. We have 3-4 stores locally and only one of them even sells CB stuff.