UHF time

[Ferret]

Hey everyone just wondering how to go about installing a UHF as I won't it to run straight of the battery and not of the accersorie I'd like to use with out keys and other reason. I was just going to run power to my battery and put a fuse between battery to UHF on the power cable nd just run negative to the body for earth will this work or no lol please guys keep it as simple as
You can thank you for your help cheers ferret

[Silver]

Since you are running the power cable from the battery, I'd suggest you use twin cable, and run the earth to the battery as well. The better the earth, the better the radio will work.

[Ferret]

So by running straight power to the radio won't blow my unit

[oncedisturbed]

It shouldn't harm the UHF at all, this is how I installed my GME 3100

[choochie]

Running UHF directly from battery is fine. As mentioned use twin core cable and use an inline fuse close to (+) battery terminal and run the negative to the (-) negative terminal.

Always good to have the ability to use the UHF without ACC key in case there is an emergency situation and the keys aren't close by.


[Tapatalk2 on Nexus7]

[Ferret]

Thank you very much guys one quick question UHF normally all run at about 5 watt by any chance will it increase it's watt by straight of the battery and my Ariel it's got the bite down washer to pearce the paint for earth aswell should I still run negative for earth anyway thank you

[taslucas]

Hey Ferret, I did the same as above, Just ran positive and negative straight to the battery. Works fine.
The battery is 12volts, just the same as any of the 12volt wiring in your car.
An advantage of this is that you can have your UHF on while your engine is off. For example if your waiting at camp for your mates.

[threedogs]

Run it to your AUX battery, just in case you forget its on. Try and leave your Start battery for just that, STARTING. You wont get any better than 5 watts thats the output of the unit, you may get better range using a 6Db antenna.

[97_gq_lwb]

Heres a bit of info for you to read. http://www.mobileone.com.au/antennas/cb477info.html

And when installing an antennae make sure the connector for the back of the radio is installed properly onto the cable i have seen quite a few that weren't even soldered or shorting and this will kill the radio in no time.

[Silver]

while it is called a 12v system, rarely is 12v seen in a car.

The alternator puts out a bit over 14volts while charging, a charged battery will read over 13 volts, gradually dropping back over time.

Whether you wire the radio direct to the battery, or to the accessory circuit, it is likely to be receiving about the same voltage. There will be more voltage drops on the accessory circuit caused by connections and wiring, but they should not amount to much if the wiring is done properly.

What you will find if you look at the specs for your radio is that it is designed to work with a range of voltages, say from 11 to 15, or even 18 it depends. So if your voltage regulator goes mad and allows the charging system to put out more than that, the radio won't be happy. It won't be happy whether wired to the battery, or to the accessory circuit

[Ferret]

Thanks guys much appreciated

[GQ TANK]

The info at mobile antenna is good - but also a bit miss-leading.

I always compare antenna gain to a balloon

Antennas quoted as dbm refer to the gain "unity gain" 1/4 wave antenna mounted in the middle of a roof. (the ballon is round and gived the same "range" in all directions.


As you increase the gain the balloon is flattend out (ie some one is standing on the ballon)

3 db the ballon is still round and gives all round gain - best for driving on the hills
6 db the balloon is flattend out and give better distance gain - compromise hill and desert driving
9 db the balloon is now a paincake - best for driving in the desert.

I personally use a RFI cd51 Gound plane independant MOPOLE antenna http://rfiantennas.com/products/uhfantennas.html - been using these for years.

[Finly Owner]

ROD, put a fuse on both lines, neg and pos! This will help if there is any earth feed back. It is true that radios have been killed by unprotected circuits against negative feedback.


I KNOW, 99.99% of people here will say BULLSH!T Tim, you only need to fuse positive feed wire, and they are correct. BUT, I listen to you guys on a lot I don't know, so I am telling you to add a fuse to you earth feed.

Better to be safe, than sad at a later date. I mean after all, we are talking only $2.00 more for that extra fuse and holder.

Tim

[GQ TANK]

The main reason for running a fuse in the negative is to prevent a ground porblem else where and they vehicle drawing its ground via the radio ground.

I have seen a fire truck, where the engine ground broke, the truck tried starting using the antenna ground via the radio. The anteanna cable got so hot that it melted though the head lining and the radio was tottalled ( $2500 ) radio & it was not coverred by warranty.

The other option is to run the ground to the chassis earth point from the battery.