How many amps dose a CB Car Radio need?

Question

How many amps do i need to push a CB car radio that runs at 13.8v. I have searched the internet for this and i cant find it for anything.

Answer 1

a 3amp fuse comes with cb radios that have fuses already installed, even if you have your radio tuned to push 20w its not 20w of power, like your thinking. So the 3amp fuse still works, its what i use on my galaxy dx959 which pushes almost 30watts sideband

3 Amp Fuse

Answer 2

Well, you can figure that the CB radio draws most current when it is in the transmit mode and modulated at 100%.  Now, there will be some secondary circuits involved but they draw negligible current in comparison.

So, if your radio puts out the legal limit of 4 watts RF plus say 2 watts of audio at 100%, and the power supply uses another watt in losses, I figure, since power = Voltage x Current

7 watts = 13.8 Vdc x Current

Current = 7 watts / 13.8 Vdc = 0.507 Amps.

I would use a 0.750 Amp or even a 1.0 Amp fuse would likely be within the limits of good surge protection for your radio.

Answer 3

About 2 Amps. Although the final is running at <5 Watts and modulation is 2.5 Watts (assuming the AM model) which would imply <1 Amp, there is quite a bit of additional circuitry which makes for some additional current.

Answer 4

Now most, and I know I'm going to get razzed by someone about this, but most CB's are only 4 watt of RF power from the factory. Now you can by some with 20 watts, 50 watts, etc. But, for most CB radios a 5 -7 amp would be more than enough to power it.

At this size of fuse you won't have to worry about burning down the vehicle either.