I have posted this question on this forum before, but really havent got anywhere with it. So here goes. My family rides atvs in the national forest, we have 3 atvs and we need to keep in touch with the riders from a base station in case of an emergency or break down. I need a radio that will cover a 20 mile radius in very dense mountainous( deep valleys and high hills) terrain. We currently have motorola maxtracs programed for the murrs frequency that run 45 watts( i know that is a little high ) But those radios just arnt cutting it. I dont know if the old radios are junk or what. Anyway i need help with this. I think i might have to resort to getting cbs with amps. Like i said, these are only used for emergencies. I am only looking to talk to the base station, not the next county. And i need it as cheap as possible because there is a good chance the radio will get wet. And ham radio is out of the question when there is 15 riders. Thanks for the help!
20 mile range, talking simplex over rough terrain is alot to ask of any radio setup.
where is the base station located in relationship to elevation and terrain, is it on top of a ridge or down in a hole or valley?
if your 'base station' is up on the highest hill, your radio setup may be crap.
first make sure the radios are working right, especially the antennas, you can have the best radio in the world hooked to a shitty antenna and not get out, but you can have a real cheap sorry radio and a good antenna and talk for miles. Is the antenna tuned to the frequency you are using, is it the correct antenna, and is it a good antenna. I think you said it was a no ground plane antenna. If it is, is the coax special looking, like extremely 'fat', if so I would look at a different design, as the reason the coax is large or has large segments is that its designed to dissipate the power reflected back to your radio. You dont need much ground plane on the VHF hi-band, and the smaller wavelength allows antenna designs that are much more efficient with little or no groundplane.
at 45 watts, you ought to be able to get through the rough terrain, but not 20 miles, with an antenna mounted low like on a 4wheeer, your line of site is not but 6 miles, however VHF will go a little bit more than line of site, I would expect a little more, and if your up on a hill, much more, but for an average range, I would figure 8 miles. Ride up to a mountaintop and your signal might go 100 miles.
They made or still make trunk mounted vehicular repeaters, I do not know much about them but I have seen such a thing. A few people are (legally) using them for their GMRS systems. They were quite popular with the state highway patrol many years ago, allowing the officer to talk on his handheld and chase a suspect and still have coms with his handheld. Ask questions about them eventually you outta get answers. You need to have your radios reporgrammed for an offset, and a CTCSS tone to block access to the repeater would also be a good idea. Input on 151.82 and output on 154.600.
Of course, my advice is total gang rape of the FCC rules for MURS, but I think you be alright so long as you dont fool around and use the repeater sparingly, for what you say you want to use if for.
It might* work with 11meters (CB), I think this band has somewhat of a groundwave effect, as it is just barely long enough wavelength to be counted as HF. The wave has a tendency to travel along the earth's surface, over hills (somewhat) , etc.
I see 2 problems with CB,
(1) is antenna and groundplane, what little metal on 4wheeler there is, is insufficient for the other half of the wave to get out. Also a 'decent' antenna is going to be at least 4 foot long, anything shorter and range becomes a complete joke.
(2) is cost, a stock 4watt radio is not going to cut it, you need sideband, and preferably more than 12watts.
I like CB for in the woods, its more private as a million other users drowns out my coms, even better to "slide" between channels, and nobodies on it anyway besides truckers. From a "eyepoker and brick" style handheld to handheld we typically get 5 miles over fairly rough terrain, with newer more compact handhelds, with short antennas, much much less, maybe a few miles, and over gentle terrain when elevation is to my advantage, well, I could talk to base (up on mountain) from the valley, 15 miles away.
