CB Radio and 102" Whip anteanna mounting?
 

I've ordered an
Uniden PRO510XL Professional Mobile CB Radio : CB and Ham radios | RadioShack.com

and as soon as next paycheck hits i'm gonna order the 102" whip.

I intend to do a custom cb mounting to my dash. but my biggest thing is mounting the antenna and running the cable. I intend to mount the anteanna to my rear bumper (i have no problem with the drilling) how do i run it through to the CB? i'm open to anything at this point so throw it at meh!

Being that the 102" (108") whip is a 1/4 wave antenna the mounting position can (and will) have an effect on performance. Mounting it on the bumper will definitely have an effect on performance because the majority of the antenna will be below the roofline of the vehicle. This will also make tuning the antenna for an acceptable SWR difficult because the signal will be reflected off the body of the vehicle back into the antenna. An option (that imo) is better would be to use either a magnetic or hard mount coil antenna (like the Wilson 1000) on the roof of the vehicle. That way the whip is above the roofline and you will not experience reflect because there is open air all around the antenna. This will give you better transmit/receive capabilty and make tuning the antenna much easier. just a thought...

As far as routing the coax for a 102"/108" on the rear bumper:
Run the coax along the inside of the frame rail up to the firewall. From there you can route it through a hole in the firewall to the back side of the dash, and from there to your radio. Keep the coax away from the exhaust and suspension parts when you route it. If you drill a new hole in the firewall use a rubber grommet to prevent damaging the coax.

Mine is mounted to the bumper and I aint had any tuning problems.

I ran my coax in the hole the power wires go from the body to the tailgate then its under the carpet.

have my whip on my rear tire carrier, doesn't give me ground noise or anything

I didn't say that mounting an antenna on the bumper couldn't be done, I was simply offering a suggestion of an alternative mounting location that will offer better results. In all honesty, the bumper is the worst place to mount the antenna for a 26/27MHz radio. Mounting the antenna on the tire carrier as Benedict did would be better, and mounting it on the roof would be better yet. You want to get the antenna as high in the air as possible with minimal obstruction for optimal rx/tx performance. Also, it is a good idea to keep your coax and power wires for the radio away from existing wiring in the vehicle if at all possible. It may introduce interference (static) to the rx of the radio. If you do have to parallel existing wire you want to keep a little distance between it and your radio power wire and coax and cross over it at a 90 degree angle.

Just curious, what is your SWR, and how did you tune your antenna?

My swr is a lil over 1 on my dosy and I custom trimmed the coax till I got it that way. Even when I turn on my foot warmer it acts just fine. I've been in and around CBs for almost 15 years, I know how to run my wires.

With 15 years experience you do realize that you can't/don't tune a 102"/108" antenna by altering the length of the coax, right? By trimming the coax all you have done is connected your meter to a point of low impedance in the coax. By doing this, the SWR reading on your meter does not express the SWR at the antenna. In other words, it is a false reading. You need to adjust the antenna itself, not the length of the coax. A properly adjusted 102"/108" antenna will be resonant at 27.1850MHz (the middle of the 11 meter band) and have an SWR reading of approximately 1.3:1 at the antenna. I'm not trying to blow my own horn, but I got into CB when you had to have a license (mid 70's) and also hold an extra class amateur radio license. With 35+ years experience in radio I have seen a lot of myths come and go, and resurface over the years. I'm glad that you know how to route your wiring and coax. The info I posted was for the benefit of those that may be new to the hobby and/or those that were unsure of how they should route it in order to avoid potential problems.

My meter stays in the truck, hooked between my radio and 200 watt x-force. I do have and adjustment on my whip that I got off the x-force forum but have never had to use it. The SWR has always been correct so I guess I'm just lucky. This is my first amp but the 3rd truck I've had the rest of the setup in and never a problem. I'm well aware the rear bumper isn't the ideal spot but it could be worse and I could be trying to run duals back there. On a first gen the 102 or 108 (with the correct spring for cb use) as you keep calling it enough antenna sticks up enough it doesn't cause any big problems. I mainly use mine for trail rides so it works fine. The rare instance I get on there to cut some mud ducks lips off it still works fine. Not broken so I'm not fixing it. My only problem is I can't find any good flexible ground straps for my doors and tail gate, they keep breaking on me and I have to replace them every year.


I got in this stuff in the early 80s cause of dad when I was still real small. I can remember when there were still tons of 23 channel radios around but having to have a ticket for CB was before my time.