Clean VHF/CB radio installs

Ok, I need some new antenna help here. Ive gone through 2 firering cables, They keep breaking right at the joint where the antenna connects. There is no stress there, the wire is loose, and its not moving, but it keep breaking. SO I have removed my radio, pulled the antenna out and am searching for a better antenna location.

My old antenna was mounted above the tail light on one of those rear spot light mounts. Im trying to decide if I should mount it in the bed, or switch to a ditch light mount.

If I do a ditch light mount, I dont want to keep using the low profile fire ring mounts, so which ditch mount will fit the whole antenna cable plug.

 

Is this for CB? You can always get a ditch light bracket extension to move the antenna away enough for a

$38 pl259 USA made PL-259 improved double shielded rg-58u for firestik antenna K-8A 18-foot single cb/ham coax cable

pl259 to a traditional stud.

If your talking VHF/UHF I’ve done a Rago NMO extension bracket and run a cheap OPEC pl259 NMO and connected directly then waterproofed the connection.

I’m also not a fan of firerings. Both the 2 I owned eventually let a ton of water end and corroded to heck. If you even slightly overtighten them they warp.

 

Its for CB. Im not a huge fan of the extension just from a looks standpoint. I dont plan to run ditch lights so I was hoping to to have a slim look.

Maybe I will just get a nice mag mount and put a port plug behind the rear seat. I only use the CB on road trips anyways.

 

Your best bet is to google ham radio and antenna testing.

 

The first thing you need is a SWR meter that covers the ham frequencies.

 

Ok, new plan and its fucking stupid, but if it works its going to be amazing.

So I have this diamond powerup/down antenna mount. Its amazing, but its I never had a good place for it. I had it on my bed rail, but was always afraid it would either grow legs, or get hung up on a load. So, I got the idea that putting it on the roof would be pretty cool, then I realized that my OEM roof rack might actually have the space inside of it for me to mount the electronics of the power antenna inside! All that will stick out of the side is the little arm that rotates and holds the antenna. I just need to decide if I want the antenna on the inside edge of the roof rack, or the outside edge.

So, here is the inside of the diamond power antenna kit, I matched it up to my roof rack and it looks to fit perfect inside the front or rear of the rack. Im going to pull my roof rack this summer to wrap my roof, so perfect time for me to get this thing installed along with some side mounted lights.

 

I assume the end bit comes off to feed through a fender. Can you get a grommet on there to seal the pivot hole?

 

Should be able, its just a metal shaft. Im going to swing by the hardware store to find a grommet that will fit this weekend.

 

Check in the electrical section wire nuts etc.

 

So since I've got my radio installed I've been having issues transmitting. The radio is a

$158 Uniden CMX760 Bearcat Off Road Series Compact Mobile CB Radio, 40-Channel Operation, Ultra-Compact for Easy Mounting, Large 7-Color Backlit LCD Display on Mic with Built-in Speaker Mic, Black

Uniden CMX760. It seems to receive fine, I can hear others transmitting and I can hear the weather. When I try to transmit I hear squealing coming from the speaker on my mic, I seem to be transmitting a squeal as well. It also seems to then stick in TX mode even after I release the button.

I checked and I believe I have a good ground, I have the antenna mounted in the front of the bed near the cab, and I ran a wire from my mount to a bolt on the frame. Mount is grounded down where the antenna stud goes, and where the wire is screwed in. When I check with my multimeter it says I have very low resistance from my antenna to my negative battery terminal. I checked unplugged the radio and tested the coax, I don't seem to have any shorts. I even ordered a second CMX760 thinking the first one was dead. Exact same issue. I can't work out what's going on for the life of me. I tried checking SWR with my meter and it doesn't seem to check right with the squealing, the antenna will kind of move all over the place but I did my best to get it as good as possible. The squealing is also kind of an on and off beep, which is where I was having the main problem checking SWR.

If anyone has any ideas, I would really appreciate it.

 

You need a good ground that is short. I had to run four 14gauge wires from my antenna mounted there just to get a halfway decent SWR. I have the same radio btw.

 

Okay, I tried to make it short as possible but it might not be short enough. Not sure what gauge wire I'm using either, might need to go thicker. Any recommendations on what to ground it to? I have it grounded to one of the bolts that secures the brake lines. Its maybe 4ft of ground wire, from the top of the bed right to the frame.

I'd like to keep it in the bed but I have to move it somewhere I suppose I have to. Thanks!

 

Thats the exact spot that I grounded to also. But yeah, it was never really good enough of a ground due to the length of the wire, even with 4 wires grounding it it was never enough. I moved my antenna to the back of the bed and had it grounded to the tail light bolts and it worked much better. Get a swr meter and check what your levels are. They are pretty cheap.

 

You may want to use flat braid for the ground straps.

 

So kind of interesting, you were right about it being the ground. I did some research on why a long ground is bad and it turns out, when a ground is long it can act like an antenna and mess with your actual antenna. I switched my ground wire to an 8 gauge really thick wire, and looped both ends through a RF choke. I also threw an RF choke on my coax and the power cable for the radio running to the battery.

It works like a dream now, I was picking up signals from across town. My SWR was 1.5 after I tuned the anatena. I might still move it down the road but I'm happy with it for now. Thank you so much!

 

Ground currents are surface currents. That’s why flat braid works better than regular wire. As you saw, a thick wire worked because it had more surface than a smaller gauge wire. I use 1” flat braid to ground my HF screwdriver antenna on another vehicle to the vehicle frame with good results.

 

any pics of the 3rd brake ligt with antenna? thanks

 

just be careful screwing into that plastic there because that is where your lower vents are routed, for the front and rears

 

A quick question about others' experience:

Mesocustoms 3rd brake light w/ NMO mount, I'm fairly certain that I'd just rip this off or bend my cab the first time I tree-smacked the antenna.

Does anyone have direct experience with this mount in the trees (or a drive-thru)?

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Hard to say what would happen if you whacked it on a limb. I don’t think your cab would bend but the brake light housing might warp if you had a non-spring antenna. Definitely would want an antenna with a spring. Even with a spring after enough hits you might see the plastic fatigue and break. It’s a lot of leverage to put on what are essentially 2 screws into plastic nut inserts to the roof. The other issue is that spot means you have no real ground, and would need to run a 1/2 wave antenna or a ngp antenna.

I had one briefly on my 2nd gen before I sold my truck. I probably wouldn’t run one if I saw a lot of forest roads. Good for the desert or open land though.

Personally I’d just put an NMO thru the roof itself with a backing plate. If you do it using a 3/4 greenlee punch it will look like a factory hole.