Mounting a CB antenna on a modern hatchback without drilling?

[drewdownkali]

Don't know when they will finally allow these message though but I have a 2003 GTI 24v VR6. MK4 body. Doubt I can post pictures. They won't let me do anything.

 

[drewdownkali]

Here are some. Mounted it higher and very little difference.

 

[drewdownkali]

Here are more.

 

[jhooten]

Hey canav844, how on earth did you get that laird/comet setup to work?? I bought the laird cb27s and the comet cp-5nmo (730 mount), and the swr is 3 and above. Comet can't figure it out, guy at truck city in Tacoma Washington couldn't figure it out. HELP!!!! Bout to send it all back and get a mag mount which I was trying to avoid.

Is the hatch metal? At least one of the set screws on the mount HAS to be tightened enough to penetrate the paint and make contact with bare metal, don't use the aluminum ovals. A ground strap across the hinge from the hatch to the body helps.

 

[drewdownkali]

Yes they are grounded. Used a meter to test. tested and retested after adding a ground strap. Ground is good.

 

[canav844]

Is the hatch metal? At least one of the set screws on the mount HAS to be tightened enough to penetrate the paint and make contact with bare metal, don't use the aluminum ovals. A ground strap across the hinge from the hatch to the body helps.

Yes the hatch is metal, as are the hinges as is the ground wire from the hatch to the frame that I put a little dielectric grease on every few years to ensure a good ground.

Never penetrated the paint with mine, just made sure it was sung enough that is wasn't going to go anywhere. Not to say that going down to the paint wouldn't necessarily improve things, but it shouldn't be nessecary (which is important to me as this was preferred over drilling another antenna hole to reduce the risk of rust).

 

[drewdownkali]

Dang I wish I could post right away. Made absolutely sure it was grounded. VW uses some kinda paste stuff around the weld seams before they paint.

 

[canav844]

How long to the nearest 1/8th of an inch is the whip of the antenna?

 

[drewdownkali]

Huh? How long is the whip? The whip in there is 48". It came with a 47" whip but cb guy could not tune it. He put a 48" in and got it best he could.

 

[drewdownkali]

Guess they put a 47" whip in the models with the spring and 49" in the ones without the spring.

 

[nonperson]

Is the Laird antenna base, the correct one for the CB frequencies? The Laird antenna I have lists the frequency range on the inside of the base. Why not drill a hole in the middle of the roof and mount it that way? I bet it will work a whole lot better! If you sell it or change your mind later they make little plugs for those type of holes.

You could probably remove the AM / FM antenna, put the CB antenna there and install a duplexer to run the CB and stereo. When you get ready to sell it replace the stock antenna.

 

[drewdownkali]

Because I don't want to drill a hole in the top of my baby.

 

[drewdownkali]

What do you mean the Laird antenna base? The antenna is sold as a high 26Mhz to 29 or 30 Mhz antenna. CB=(CB)27=(Mhz)S=(spring) CB27S

Manufacturer Laird Technologies
Model # CB27S
Product Description 26-28 DC Gnd Base Load with Black Coil, Black Spring & Whip (Solid Black)
Frequency (MHz) 26-28
Product Narrative DC grounded base-loaded antenna. Higher power handling and less ground plane required than standard base loaded antennas. Internal and external contacts are gold plated for best conductivity.
Gain (dB) Unity
Maximum Power (Watts) 500
Whip Length (In.) 49"
Whip Material 17-7ph tapered stainless steel
Mount Type Order separately from NMO style mounts
Cable N/A
Connector N/A
Warranty 1 Year

 

[drewdownkali]

That is from antenna farm but it actually comes with a 47" whip, and actualy says to 31Mhz

 

[drewdownkali]

I want a clean install. I want something I can take off whenever I want. I don't want to pay a fortune to have some drill a hole into my car! I don't want to have to deal with leaking and rusting.

 

[nonperson]

That is from antenna farm but it actually comes with a 47" whip, and actualy says to 31Mhz

That's it! The antenna is based loaded and if it's the wrong base for the band then it won't work right. Doesn't hurt to double check these things in case they sent you the wrong one in the package.

I want a clean install. I want something I can take off whenever I want. I don't want to pay a fortune to have some drill a hole into my car! I don't want to have to deal with leaking and rusting.

Unless you make the hole to big it won't leak. The Laird VHF antenna, I own, has been on two different trucks now and doesn't leak. BTW they have or at least mine has two o-rings to keep things dry on the inside. When I took it off the other vehicle I didn't see any rust forming in or around the mount. Making the hole is easy if you have a GOOD drill, appropriate sized hole saw bit or step bit. They even make hole saws just for NMO mounts but they aren't cheap.
I can take mine off easily! All I have to do is unscrew it. They make caps, plugs, grommets or whatever they are called that can go in the hole. Just saying!

It's clear you don't like NMO or any more permanent mounting options. With your vehicle, your option(s) are going to be very few and the performance of you radio is going to be even less than ideal as a result. Even some of the better options are a compromise, at these frequencies, on most vehicles. Good luck!

FWIW I'm having CB antenna mounting issues on my current vehicle. I have a LOW SWR but I don't think the mounting location is ideal. I don't seem to have the range I use to have on the other vehicle I had.

 

[drewdownkali]

LOL. What do you mean thats it? Base loaded just meas the coil is in the base. It's not the wrong antenna for the band. it covers 27 to 31 Mhz. This already is an NMO setup. I based this off someone else who used same materials on a later model of the same vehicle. And if I drill and it still don't work then I have a hole with nothing to put in it. Lol.

 

[drewdownkali]

And nothing to show for it.

I have a NMO mag mount coming, this will probably answer my question about the antenna if it works. I will probably buy another radio just to eliminate that from the equation too. Only other thing I can think is to put the whole setup on my buddys truck and if it works then it just must not work with my car. I even put it on my hood and swr was still 3 or above on all channels. I am pretty sure that changing the length of the antenna would not do much unless one end of the band was low and the other end of the band was high. Am i wrong in this assumption?

 

[mmckenna]

Yes the hatch is metal, as are the hinges as is the ground wire from the hatch to the frame that I put a little dielectric grease on every few years to ensure a good ground.

Dielectric grease is an insulator. It does not conduct electricity, so expecting it to ensure a good ground is incorrect.

But, I don't think this is your problem.
First, it sounds like the CB guy you are dealing with doesn't have a lot of RF experience. He may be able to sell the parts, but his troubleshooting skills are lacking.

There are a couple of things you need to check, SWR isn't the whole story. Since you said you were checking grounds, I'll take it you have a multimeter and understand how to use it. That's the hardest part for most people right there...
1. You need to check for continuity from the center pin of the connector on the cable to the center of the NMO mount. If you don't have continuity here, stop and fix it.
2. Check for continuity from the outer shell of the connector to the outer ring of the NMO mount. If you don't have continuity here, stop and fix it.
3. With the CB disconnected from the antenna and the antenna removed, check for continuity from the outer shell of the connector to the center pin of the connector. If you have continuity here, stop and fix, you have a short in your cable.
4. Now reinstall the antenna. Check for continuity from the outer shell of the antenna connector to the center pin. It should show continuity. If it doesn't, your antenna coil is bad.
5. Remove the antenna from the mount. On the underside of the coil, check for continuity from the center contact to the outer ring. There should be continuity. If there isn't, you've got a bad coil.

If you pass all of the above, you need to start looking in more detail:
1. Your SWR meter could be bad, not calibrated, etc. If you keep getting failures, don't rule out the test equipment (or the test equipment operator, for that matter).
2. DC ground and RF ground are two different things. You may have a good ground on the antenna mount when you check with your multi-meter, but it doesn't mean it's a good RF ground. Ideally you might want to try relocating the antenna/mount to a different part of the car to see if it improves.
3. Mounting a CB antenna down below the top of the vehicle with a lot of metal next to the whip is going to give you not only poor performance, but bad SWR. You need to get the antenna up in the open, away from metal. You may be coupling the antenna whip to the cars body and detuning everything.

You should be able to make this work, but you are going to have to do the basic check steps above and make sure the installation is good before you do anything else. Then, make sure you try a different SWR meter, this wouldn't be the first time (and it won't be the last) that the test equipment was faulty. Once you've ruled all that out, it's time to start moving the antenna around to find the location that works on your car. Until you've done all that, you are just chasing ghosts.

 

[drewdownkali]

I have done a lot of checking for continuity.Believe I have covered 1 and 2 in the first category. Have to check into 3,4 and 5. I have tried mounting it higher, not sure but think I put in picture for that. It made it a bit lower but not by much, 3 down to 2.7 or so. I tried on the hood just to see if there would be a difference. Is it possible it could be the radio even though it's modulating? With #3 are you talking about just checking from center pin of coax to the outer barrel?