I’ve received a few emails over the last couple of months from CB’ers having a specific type of trouble with their rigs and its been surprising how many of these are being cause by not giving the CB enough juice to do the job properly.
Adding a linear amplifier or sometimes even just a quality peak and tune can seriously up the power requirements and many people forget to add a few more amps to cope with the CB’s changed specifications. Running a basic CB on the bog standard 3 amp power supply is often barely enough for good operation and using at least a Larger 5 Amp Supply will make things perform that much better.
Note :- Older rigs tend to be more power hungry for many reasons with a main one being a bulb lit display instead of a more easy going (power wise) LCD setup.
First, Don’t Panic!
With most of the power needs of a CB being in the 4 watt (or so) RF amplifier that gets your signal out, its when you key the mic that things normally start to go south.
If your rig comes back on after the ‘brown out’ and there’s no smoke pouring out the back you can ignore that Arrghh! moment, take a deep breath and realize that this is something that can be solved with a little bit of logic. Take a good look at the wiring to make sure all connections are solid then switch the CB down to the lowest power setting and try again.
A successful key up with these settings means your power supply just isn’t up to the task of driving the radio at full power. Any other result means either serious problems with your CB, power supply or wiring as the current needed is easily delivered by even the nastiest budget CB radio power supplies.
Correct Wiring for the Demand
Some of the other common power problems can be produced by sub standard wiring. A certain level of current needs a certain thickness of wire to carry it properly and although thinner wire may not burn out while struggling with a few extra amps, it will cause issues when trying to get that CB operating properly.
If your CB comes with hardwired 12VDC power leads these (should) be the correct gauge and if you choose to extend them always use the same type.
Having an internal linear amplifier fitted requires a fair amount of modification in the way the CB handles both DC/RF power and if its been done by someone qualified, the power leads will be replaced to deal with the new current drain.
Go Large (If You Can)
Don’t just settle for a power supply that’s on the limit of what you need but go for something that delivers at least 10 to 20% more than the rig needs.
Future proofing is always good and if you can get a hideously massive supply at a cheap enough price then go for it as you never know what your interests will switch to down the road. Remember that as nearly all CB/Ham mobile setups run on the common 13.8 VDC standard, it can always be used for something else.
Also looking to the future is the fact that a well cared for large capacity power supply is an easy saleable used item (if only a little heavy if you have to ship it somewhere).