"Chris" wrote in message
news:CoySc.66092$sh.37930@fed1read06...
How many amps does a mobile cb radio draw? I have a Uniden Pro520xl. I
computer power supply has 12volt connections would it be enough to power
the
radio? I have a DC plug adapter that is 14volt, 360 milliamps and a 13
volt, 800 milliamp. The 14 volt plug gives poor audio quality even from
a
100 feet away and the 13 volt just blows the fuse. Any comments?


In computer power supplies only the 5v output is regulated. The 12 volt out
put is unregulated which means that as you draw current the voltage drops.
It's pretty low to start with (13.8 volt is the recommended voltage for
mobile radios) at 12v and you'll find that if you transmit or wind up the
volume the voltage might well drop to 11volts and the rig will not work.

The DC plug adapters arn't going to give you enough current you'll need more
than 1amp = 1000milliamp on transmit It is likely that you have got the
polarity wrong on the 13 volt adapter is swapped over i.e. you are
connecting possitive (red) to negative (black) by mistake. This will blow
the fuse.

Suitable power supplies are available from Maplin and sold as "Regulated
13.8v Power Supplies" and come in a range of max currents from 2.5 amps to
30 amps. The 2.5 amps will do at a pinch. 5amp might last longer.

Gareth
www.g1lvn.org.uk