After reading on the board for a long while now, to my suprise I have come across more and more fellow yotatecher's who are interested in cb's or inquiring about how to mount them, where to mount them, and how to tune them. Anyhow, thought I would post this long overdue link that describes my radio setup. If there are other serious radio users maybe they can benefit from this post.
Radio is a Conxex 3300hp. Radio does about 40 watts on my DOSY at peak envelope power. The linear is a FatBoy Products with 5 2879 transistors doing about 1000watts when ran at 15volts. My current single alternator and single battery only run maybe 13volts to my box and I am seeing around 800watts from my inline DOSY meter with the fatboy turned on. Antenna is a Monkey Made Longshaft, with cut down 102"whip as the stinger.
My standing wave ratio(SWR) is 1.1 to 1.2 across the band. Because of the wind resistance from the HUGE flat coils on this competition antenna I had to forego the traditional mounting bracket on my toolbox, and build a custom headache rack for the sole purpose to mount my antenna. I used square tubing and flatstock for the mount and ran a 6gauge wire from the mounting bolts on the bed to the frame for added ground(without good grounds, the swr and reflected power can blow up your radio and or linear).

Other Notes on my setup: My check engine light has stayed on for years and will not go away. I believe this is due to running so much power out my cb. I am not sure if the spurious emmissions from my radio is going to fry my truck's computer but so far everything has been fine for the last year. I have heard rumor that many computers have been fried thanks to high power radios....just food for thought.
NOTE: I do not use the linear amplifier on the cb or any am channels 26.965mhz to 27.405 MHz. It used for experimental and scientific use only on alloted amature bands.
Enough with the babble here's my setup pictures, enjoi:

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nice, wats with the fan where the center console should be?

 

That "fan", keeps my transistor box cool when I am talking on the radio. The reason it has a fan is because on long keydowns, when I hold the mic keyed for awhile that box will get really really hot. That is just part of my cb. I removed the center console to fit it there. It's weird looking and odd if you have little knowledge on amature radios or cb radios.

 

nice setup. i like the cut down 102" whip as a stinger - we had to do something like that too on my friend's MM. i like the mount on the bar - if i had the skills and equipment, that's something i wish i could do myself.

3300HP - good radio! should have plenty of output and swing to drive a volted 5-pill.

your stock alt and single batt might be taxed kinda hard. it's not too hard or expensive to upgrade the alt - you can either go aftermarket or stock rewound (cheaper, as long as you use your original as a core exchange).

some of the more hard core guys replace their a/c compressors with additional alts, some even go so far as to have custom brackets made, use serpentine belts from mustangs, and run three or more alts. if you don't have one already, an optima yellow top or blue top might help you with a long keydown if you're limited to a single battery. lots of folks here have added additional batteries under the hood as well.

a rewound alt. and optima yellow top have served me well for years, but i'm nowhere near 800w, much less 1K.

re: check engine light- as you speculated, it's probably due to RFI. your box is kinda close to your computer, and a box that size probably generates a fair bit of RFI when driven hard.

the Connex probably isn't the problem, i've been using a tuned SS3900GHP for years near the dash of a 98 T4R w/ no problems. if you had enough distance, you might be okay. i ran a six pill in the trunk of a maxima, and in the rear cargo area of the T4R, w/ no interference, noise, or check engine lights. ground, ground, ground.

just my .02 on the RFI. nice setup!

 

yeah i dont know much about them, i run a cobra 27 nightwatch with a 5ft firestik, just simple stuff

 

Thanks for the information. My stock alt, and battery don't seem to mind the load at all so long as I keep the rpm's up a bit, which isn't an issue while driving. Also, I would love to mount the box further away, but I just don't have the room, although I guess I could mount it further away, or maybe even in the toolbox so long as I used a remote switch in the cab. That's an idea. Your right about grounds. I couldn't get my swr's down below 1.5 and ended up running 6 ground straps from the chasis to the frame. As soon as I checked it all out, the added grounds dropped my swr almost to 1.0!

A cobra 27 and that firestik will work great and give many years of helpful service. There really is little use in having such a ridiculous cb setup as I have, unless you want to talk "worldwide".

 

Crazy set up man... don't you get hassles going under bridges and stuff with that whip? What kind of range are you getting with that combo?

 

Suprisingly I have no issues with bridges whatsoever. The whip does hit alot of stuff at 50+mph and has yet to get bent, dented or break. I occasionally will hit overhead phone-lines in residential areas but it is not a big deal. What kind of range do I get? Well depending on the conditions: meaning weather and sunspot cycles, I can range between 40+miles on groundwave, to 3000+miles skip. I talked to Guatemala last week, and had a quick contact with the West Indies today on channel 28am. I talk to Florida and the southeastern united states weekly

 

holy smoke! If I ran a set up like that around here I'd be hitting the streetcar power lines all the time which would probably not be good lol...
you could have a sweet little pirate radio stn. there... be hard for the FCC to nail you too being mobile and all heh heh heh

 

ah, okay... just don't forget to keep the rpms up. stock batteries aren't too happy being deep-cycled too many times. might want to eventually look into a yellow top or blue top.

i've seen large amps with multi-battery, multi-alt setups actually stall a 350 chevy unless the owner is flooring it at keydown.

for max voltage to the amp, you probably want to run a decent size power cable. for an amp that size, i'm thinking/guessing 4/0 minimum. many times, the amp will draw as much current as you can feed it, so if you can minimize resistance, the amp will put out more watts.

i've seen multi-battery and amp setups in the beds of pickup trucks with camper shells, i've even seen amps and batteries mounted in tool boxes (bed mounted kind) but gotta be careful to ground well and keep them cool. also, if you're using regular marine batteries and not the sealed gel cell types, ventilation is also important to prevent hydrogen gas buildup in the box.

remote switching is not hard, some mfrs sell kits with little faceplates and labelled switches, but you can do the same thing with some surplus wire and a switch - just extend the wires to the factory switches on your amp to a switch (or switches, if you have variable power), mount on little project box or directly to your dash, and you're good to go.

 

I am thinking of installing a second alternator with adjustable voltage, and running the amplifier off that. I just installed an autometer volt meter to see how the charging system is doing during keydown. Suprisingly at 1600rpms, the voltage drop during keydown goes from 16 to 15, at idle it drops below 14 on a long keydown. I have researched motormauls(multiple battery setups using one high-output alternator) but I think, since I have the room, another alternator would be a better way to go. As far as using a better battery, preferably a deep-cycle battery; I have yet to try that. I may replace my current batt with a deep cycle and see what happens. Also,
you stated run the biggest wire possible, well I am running 2 gauge fine-stranded welding wire to the amplifier, and the same gauge wire to the engine block for the ground.

one more thing, WHAT KIND OF GUYS are you running around with that have that kind of ridiculous power as to stall out a small-block chevy!?!?! That's nuts man. I can't imagine the rf those kind of "big radios" are putting out. I imagine that would interefere with tv's and computers for miles!? My small 1000watt mobile tears up toooo much stuff already, so much so I won't even key it down in town anymore.

 

"Honey! the tv is on the fritz again! I'm missing Guiding Light!"

"That #$^%# mgrchad! He's on that #$^$ radio of his again!"


I could'nt resist...

 

tuning in tokyo tuning in tokyo.. Jeez mang, Do you pick up tarnsmissions from space with that thing?? Hi powa!!

 

Unlike a lot of high-power radio users, I use a little common sense, and am polite about running my amp around houses. I travel alot, so it gets used over the interstates most....it helps to keep me awake and passes the time while I'm driving to west virginia, new york or n.c. for climbing.
but let me tell you, if I wanted to ruin your evening of watching "Guiding Light", I certainly could

 

I never watch that crud and it's on in the afternoons anyways... unless the mrs. in question was tivo-ing it lol .... the husband would probably get on his knees and thank you anyway...

I was just trying to find the worst posible show you could mess up... LOL

 

motor mauls, if set up properly, can be an effective way to run on batteries with a single alt. a second alt is a good idea, but you can set it up to recharge a single deep cycle or a bank of deep cycles for optimum voltage stability to the amp.

you can use a voltage regulated alt, too... lots of the comp folks use those, or use external voltage regulators with cooling fans.

just got to watch the specs of the alt, though. many h/o alts don't put out rated output at idle, they're rated at a certain rpm. voltage at idle can actually be less than stock alts. unless you want to floor it every time you key up, you might want to look into overdrive pullies for h/o alts.

a deep cycle can withstand multiple deep discharge cycles better than a stock battery, so if you only have one battery and you need it to start the car reliably, you may want to consider that. optima yellow and blue tops are popular choices. car stereo gel cells are also popular, but pricey.

that's a good choice - welding wire is a cost-effective solution (some people run 2/0 car stereo cable, but it's expensive). i like the 2/0 or 4/0 (depending on predicted amp draw) welding cable myself. again, ground the heck out of everything, and you're good to go.

ah, the unlimited class, a/c class, and "sky's the limit" classes generally run long-nose 'burbs, vans, or other p/u trucks with small or big block motors (generally modified as well). they use multiple leece-neville alts, or even generators for a/c tube classes, and pretty much fill up the bed/cargo area with batteries and amps (sometimes putting out over 10K watts).

even if they floor it, the drag on keydown can dramatically reduce rpms, or even stall out a BBC if it's not floored.

and yeah, they put out ridiculous RFI. there's some keydown videos on the internet that show the video totally fuzzing out when the competitors keydown. i've seen streetlights turn on in broad daylight, people light up flourescent tubes from 6 feet away, etc...

tvs, bank intercoms/pa systems, store muzak, etc... all fall victim to irresponsible use of power. even cars with ECUs that aren't properly shielded, or systems that aren't grounded properly, can wreak havoc upon ECU/ECMs. i've seen windshield wipers turn on, power windows go up/down on their own, doors unlock, etc... at keydowns.

 

nah, can't pick up space transmissions, but i bet they can hear us...

 

Merlin, straight up, you know what your talking about. AWESOME. In your opinion what would you do if you were in my shoes. I want to see 1,000 watts solid at peak modulation out of my box. I don't care about the whole "s" unit theory and such. For no other reason than "just because" I want that 1000 watts. I know this box is capable of it no problem.
Cheapest best way? Extra alt w/ overdrive pulley+batteries. Add batteries in a series and get my current alternator re-wound so it can keep up with charging them? As soon as spring rolls around and my hours kick back up, I am planning on bumping up my system so I can turn this rig into mean skip-shooter....and still use as my daily driver.

 

hey... I can pick up alot of people on my cb but I cant get any of it very clear is it my antanna tha t needs to ve adjusted I wasnt very clear on the set up once i installed it ....???

 

yeah, adjust it. then you probably could talk to aliens, lol