Yea, that would be a problem where I live ... too many bridges and structures. However, the idea of the ball mounted 102" whip intrigues me. It was explained before that the ground plane for the magnetic mount on top would be optimized by mounting it mid center of the roof. Can someone explain the ground plane and its effect with a side mounted 102" whip? Or am I being too anal on this topic?
A proper peak and tune just fixes the problems you see in mass produced products. You have people putting these things together that are only there for the paycheck and nothing more. For this reason you will see many variances in radio performance when compairing multiple box stock radios of the same model. As for antenna. You might see better performance with a non mag mount setup in the center of the roof. Find dead center get a through the roof type mount and get your drill out. Once you have this done then find a shop with a swr meter or antenna analyzer and get your antenna properly tuned. I am a big fan of metal whip style antennas. Wilson 2000 or the K40 r even the wilson 5000 if you feel on spending more cash. I am gaining intrest in the coil type antennas such as the Predator 10K. They can get quite long (around 7 ft) but many have said that they tend to do better in transmit and receive over some of the common loaded antennas such as the Wilson or the K40. http://www.rightchannelradios.com/hood-roof-cb-mounts-83/roof-dome-mount-259.html I am also a fan of over engineering things. This is why I use 10 or 8 guage wire for my setups. I make sure the grounds for the radio are as good as they can be. I run a chassis ground as well as running a wire directly to the battery. My positive connection is also direct to the battery with a fuse in line. I also run a noise filter in line to help reduce any possible noise for the vehicle. I am not big on powered mics so I recomend staying away from them. I am a huge fan of good noise canceling mics such as the Astatic 636. Get a gear creeper also. it retracts the mic up and out of the way so it is not just flopping around in the vehicle. If you run at night then stay away from anything with blue leds. They are too bright and cause you to loose some of your natural night vision. This is why I like my nightwatch cobra 29. It has nice soft lighting that can be easily seen at night and is still bright enough to see during the day with just a glance. You can also dim the lighting on it even more for night time running. As far as the legality of radios, well no one cares as long as you are not intruding on them. You can run what ever power you like as long as it is not bleeding over 10 channels. Heck most could careless if you are running the higher powered export radios as long as you stay on the Cb frequencies. I am telling you now that the legal 4 watts will work just fine out in the open country but once you get closer to urban areas with alot of truck traffic then you will get drown out by the many higher powered setups that people are running. It can make it a pain if you are trying to raise some type of comunication with someone and someone else keeps keying up on you.
So, adding another loud radio to the fray adds to the disturbance, correct? Like sitting at a party when everyone is yelling at one another instead of turning down the music to a tolerable level and talking! For urban areas we have cell phones with internet access ... local info abounding. Out in the rural areas there is often dead space for cell phone access. This is where I really wanted a nice, clean sounding 2 way radio setup to come into play. That and the solitary trips I make to Denver ... nice to have another voice in the van.
Sometimes you have to yell louder to be heard. If you just sit back and whisper then you will go unnoticed. hate to say it but that is just a way of life. I do find that a little more power can also help out in the country side so that you can reach them farther stations. I have done 10 miles on 4 watts but 50 watts or more can get me beyond that much easier. 400+ watts gets to my freinds that have turned down their radios to get rid of extra background noise. I hale them to make contact then we switch to the quiet "farm" channel and I can dial back the power a bit and we can talk back and forth.
As far as the legality of radios, well no one cares as long as you are not intruding on them. You can run what ever power you like as long as it is not bleeding over 10 channels. Heck most could careless if you are running the higher powered export radios as long as you stay on the Cb frequencies. Very well said Rat. And adding another loud radio to the fray is not going to hurt anymore than me blowing my nose when nobody else is around. But for now just try your k40 and see how well it works with your Uniden. I ran a K40 mag mount years ago and got out well. Also most CB radio say that they are 4 watts. When they are really less than 3 watts and 60% modulation out of the box. An simple adjustment of VR-4 can help bring the audio up.
Basically, the antenna requires metal under it for the waves to bounce off of. Without metal under the antenna the waves will not bounce as well off of that side. Also antennas don't exactly like metal to the immediate side and certainly do not like metal over them. Unless your van has a lift kit and the bridges are very low, you probably wouldn't hit a bridge, and even if you did the 102 is quite flexible and can take a lot of abuse. Now you may hit some tree branches but again the 102 is pretty flexible. Below is my last vehicle that had a 102 whip in it. It stood maybe 13 feet tall at the tip in how i had it mounted. Never once did I nail any bridges, but I did hit a few tree branches, bank canopys, and the canopy at the local Mc Donalds. It didn't even hit any of the stop lights or overhead power lines in town. Never once hurt it or the truck. It did make a few people wonder "WTF". I even once had a gate guard ask me "can you talk to China with that thing?"
Allow me to inquire further on this topic; Assuming the whip is positive under load and the sheet metal of the body is negative, what keeps the 102" whip from blowing fuses when contact with the body is made, either from wind or other influence?
Because there's no DC on the antenna element. DC ground is only coincidentally (well, kinda) similar to RF ("radio frequency") ground. You *could* have a floating ground plane that's not electrically connected to the cab and frame and battery, as long as it's electrically connected to (or very near, in the case of a magmount) the metallic plane that's perpendicular to the long axis of the antenna. F'r instance, if you had an all-fiberglass cab shell and sleeper, you could remove the headliner and line the underside of the roof with copper foil of the kind used by stained glass artisans (and that I use on electric guitars to shield electric guitar controls and pickups). If you had enough foil over a large enough area, the antenna would work fine. And if your radio were one of the ones that can be used on either a positive- or negative-ground vehicle, the black DC wire wouldn't even connect anywhere to the case of the radio or the braid of the coax. So it doesn't matter if the metallic whip touches the body, except that during the time it's touching or very close to the metal body, it will affect the antenna's tuning because of the capacitance added to the system. And, FWIW, the tip of a quarterwave antenna has a voltage peak (and a current minimum), so it's a great place to pick up a considerable burn if you're transmitting and for some reason holding onto the end of the whip. The antenna whip is isolated from any DC inside the radio by components called capacitors. Similarly, the DC is isolated from any RF by components called chokes. Sorry, you asked what time it was, and I told you how to build a clock. Am I still helping, or am I making it worse? -- Handlebar --
