CB install questions.

[SubAlpine]

Installing my new cobra CB and had a question. The manual says to attach power to an empty fuse, which I have access to and will be fairly painless. I have read that many people power directly to the battery. I am leaning towards following the factory suggestion and going to a fuse. Will this affect reception?
Thanks all.

[Hypoid]

The answer is no, I think. The only difference I see is the unit will work with the key off, or even in the ignition.


We need a "popcorn" smiley.

[javaman34]

I've always tied it into the fuse box or tapping it into the power wire for the stereo. Never had a problem with reception.

[xaza]

Going directly to the battery increases chance of engine noise. Better to use fuse block with a constant power supply. Most important thing to prevent engine noise and get most out of unit is a good solid ground. Make sure and scrape all paint away first. Don't forget to turn CB off when you are done.

[Max]

http://www.firestik.com/Tech_Docs/Radio-Trouble.htm

[SubAlpine]

Ok, I read through the fire stick faq, and they suggest direct battery power. The unit already has an inline fuse, so I am not worried there, so I may try both and see if there is any difference in reception.
Thanks all.

[Jim]

I would not think you'd notice any reception/transmission diff as to how the unit is powered [edit: so long as it's getting sufficient power with a good ground path]. I would anticipate much of the performance issues would be tied to good antenna layout and install.

Me, I prefer an always-on connection (that I have to remember to turn the CB off) but I think power (switched / unswitched - both would be fused) is mainly a preference issue.

[The StRanger]

I bypassed the inline fuse and wired right into the audio fuse.
Never had a problem. Key off, C/B off.
But remember, I have my C/B in the back so if it wasnt wired that way Id never turn it off !

[Hypoid]

http://www.firestik.com/Tech_Docs/Radio-Trouble.htmDamn! I guess I've been lucky.

[96blkbeauty]

I've always wired my CB's directly to the battery. As mentioned before, a good ground will cut down/out engine noise.

I'd take your CB and antenna to a CB shop and have it properly peaked and tuned.

[The StRanger]

http://www.firestik.com/Tech_Docs/Radio-Trouble.htm

Might have to rethink my wiring !

[Jim]

My SWR is/has always been high - one of the things "to get done"...

[The StRanger]

I just need to get mine Tuned up ..

[javaman34]

I have an old CB sitting around here I use to use when I drove truck OTR. It is a Uniden PC66A. Been offered some pretty good money for it. It is all tuned up and sitting on a shelf. I'm planning on installing it in the Bronco. I even have the antenna that is tuned to the radio.

[sunk]

Any aftermarket accessory that you wire up should always be fused. It is always a good idea to wire to the battery and any ignition circuit you wire to needs to have a sufficient gauge wire to accommodate the additional load of the accessory you are powering.

If you need your CB tuned/troubleshot I will be happy to help out.

[WW2AVG]

In the ham radio world they always say to get your power directly from the battery and to fuse BOTH the positive and the negative.

I am not home now, but I will be on Thursday. I can check my books then and give you the reasons why that is recommended.

I know some folks like to have it on a line that is only on when the ignition is on. I leave mine wired to the battery and on all the time. People sometime cite the fact that if you leave it on it will drain your battery. In receive mode, the radio draws very little. I have come home from wheelin' and left my radio on for a day or two and never even noticed any significant drain on the battery.

[carpenle]

If you need your CB tuned/troubleshot I will be happy to help out.

I need to have mine looked at, I can not get out or rec. very far. I am thinking it is my mount and ground plan, but have not got it dialed in.

[sunk]

PM Sent

[sunk]

Another note on wiring, fusing the ground side of the circuit is not necessary. Your ground lead should be attached to chassis ground vs battery terminal ground. If you used a fuse on the ground side and it popped the current load will find the easiest path to ground which may be thru your CB and cause damage.

[WW2AVG]

Another note on wiring, fusing the ground side of the circuit is not necessary. Your ground lead should be attached to chassis ground vs battery terminal ground. If you used a fuse on the ground side and it popped the current load will find the easiest path to ground which may be thru your CB and cause damage.

Hmm... The American Radio Relay League (ARRL) is the "authority" in the ham radio world here in the US. For what we are talking about (installing mobile transceivers in a vehicle) we can consider CB and ham to be the same. They profess going directly to the battery and make it a point to fuse both the positive and the negative lead. That went against what I was used to, but I read the reasoning once and it made sense. I would suggest doing it.

As I stated, I am not home, so I don't have access to my ham radio reference books. I will have to take a look on Thursday. If I have a chance I will take a look later and see if they have anything on-line. Again, I just recall that rationale being quite sound when I read it years ago and I have just gone with it since. I must be getting old as I used to remember things like this! :)

[sunk]

So, I had to look it up. I have been a radio technician for 10 years and I have seen the negative lead fused on some manufactures wiring packages before and usually cut out the fuse (just another failure point). What I have found out is if you wire the negative lead to the battery, it is recommended to fuse the negative lead so that if the ground connection to the chassis fails all of the battery current does not use the radios ground path back to the battery. This is only needed if you wire the negative to the battery terminal and is not needed if wired to chassis ground.

[WW2AVG]

Ah yes, that makes sense! Good job!

For my money, I'd always go straight to the battery with both positive and negative and fuse both. That works for me and if the ARRL recommends it, I suspect that there is good reason for it. Now that is not to say that other options won't work. Frankly, I have a mini-van that I put a CB radio in. I ran it off the cigarette lighter. It seemed to work just fine. I was simply too lazy to go back to the battery and the cigarette lighter was quick and easy. It wasn't ideal by any means, but it worked.

For my Jeeps I have always gone back to the battery. It was easy enough and I considered that a bit more important that it work correctly in case of emergency. The extra effort to "do it right" (meaning per ARRL guidelines) just wasn't a big deal, so I just went that route to (hopefully) eliinate a few potential problems by wiring it differently.

Well, that's my two cents! And thanks again for looking that up!

Dave...

[sunk]

There are lots of reasons not to wire direct to the battery, the biggest reason is to avoid corrosion. Over time battery terminals get corroded from battery acid and will cause intermittent failures. Also if you are running multiple aftermarket accessories, battery terminals become too busy and can also be the cause of problems (usually loose connections). If you are planning multiple accessories, it is a good idea to plan your installation around some sort of power distribution module that can provide sufficient load capacity and both B+ and Ign circuits without crowding your battery terminals

[sunk]

So, I did learn something from your post Dave, and I really enjoy a good question/debate, especially when it is a source for for potential problems I deal with every day.

Motorola techs use a forum called Batlabs for technical questions and problems. I could not leave well enough alone and started looking into this topic on the board. Turns out people have been arguing about a negative side ground pretty much since they opened the forum. There are great arguments for and against fusing the ground side, but the usual conclusion is to go to chassis ground.

One of many example threads: http://batboard.batlabs.com/viewtopic.php?f=8&t=56844&p=265635&hilit=negative+fuse#p265635

That being said, most of the transceivers the techs are dealing with on Batlabs are VHF or higher frequency radios. One argument for going to the negative battery terminal is that it is a "quiet" ground (less noise from the ign system on the vehicle). With a HF radio like a CB, noise from the ign system is more likely to affect the CB because of the resonant freq.

One could argue that if grounded properly to chassis ground you would not be affected by this issue. You could also go so far as to install noise filters on your power wiring although I would not suggest this unless you have done the proper troubleshooting.

So what is my suggestion? Chassis ground and ensure the ground is solid, clean and not busy.

Sorry for the thread jack Chris, the location of your power connections do make a big difference in the performance of your radio.

[WW2AVG]

Hey Adam (et al),

Well, I would like to think that the purpose of these threads is to gather information and opinions to arrive at the best solution, so IMHO I wouldn't really call it a thread jack!

I liked your comment on having too many wires connected to the battery terminals! I am guilty there! I end up with CB, ham, ARB compressor, etc, etc hooked to the battery terminals. I do like the idea of coming off the battery and going to some nice buss bar sort-of arrangement, that would be good. Care needs to be taken to keep the hot 12V properly protected, but it is a great idea. For me, that's a project for a rainy day! Maybe one of these days! But I keep all my battery connections clean and as neat as possible.

I read the page that you referenced above. Same debates going back and forth there. I can see that going right to chassis ground will provide less voltage to the radio since the steel chassis will have more resistance than copper, but in reality, that is probably a trivial voltage drop and I would bet that the voltage to the radio is still well within acceptable limits. As far as noise, I'd bet that the battery connection is going to be quieter. But, again, is it significant/noticeable? Probably not for a CB! By connecting to the chassis, you are banking on the grounding between the battery and the chassis to be good. What are the chances that connection goes bad and you need the radio? Probably slim.

I think most agree that you run the 12V back to the battery and fuse it. If you ground to the chassis, no fuse is needed. If you go back to the battery, then yes, one is strongly recommended. I like running both positive and negative back to the battery. I'm not worried about the "extra cost" (a few dollars at most?) to do that and I just feel it is a slightly better setup. Did I gain much? Probably not enough to really measure, but I'll take it!

I totally agree with your comment on noise filters. I'd avoid them and use them only as a last resort if absolutely necessary.

Just kicking around ideas here! I think some good points have come up!

Dave...

[SubAlpine]

Wow guys. Awesome. Love to see a good, rational, researched debate! If only congress was the same.
So let me see if I sort this right.
Ground to battery may eliminate noise on radio, but may not be worth it on a cb, but will require me splicing in a neg fuse. I am guessing our patrol vehicles are wired for max quietness, but that is first responder stuff.
Ground to chassis needs to be CLEAN, no fuse.
I am going to wire power to battery, I like the idea of monitoring radio while sleeping in the rig, with ignition off.
Again, thanks all, that was great.

[The StRanger]

Once I get mine rewired I can get it tuned.

[SubAlpine]

Ok, cb installed, lots of static. Pick up some voice like noises, but nothing clear. What is the next step?

[Max]

Ok, cb installed, lots of static. Pick up some voice like noises, but nothing clear. What is the next step?

Dumb question, are you just listening, or do you have someone with another CB nearby trying to talk to you?

I turn mine on sometimes just for fun and I don't hear much here in town. It could be working fine, but just have nothing to hear where you are.

[xaza]

Max is right, might not be anybody in range talking.
You should still check your swr, can burn up a CB if it is off. I have a meter and could help. Not much experience with them but it is pretty easy.

http://www.firestik.com/Tech_Docs/Setting_SWR.htm

[SubAlpine]

I drove around the c470/i70 area to ward rd at the truck stop and it never really got any more clear. I do have a buddy with a cb, we were going to see if we can hear each other and play around with ranges. I guess I just figured I should be hearing some truckers at Ward rd.