Burbinator
1/2 ton status
Interference generated by an EM/RF source will get into the radio VCO/audio circuits without some kind of filter. This is true whether it is AM [cb] or FM commercial communications equipment. Most modern electronics have this filtering built into the DC power supply to almost all but eliminate it and are usually overengineered to compensate for a range of variables. CB's however, are relatively "low tech" by comparison to commercial grade communications and some older and newer models [cb's] do not incorporate a filter of some sort or not enough. A "dirty" supply line will also cause interference in almost all applications without an active filter of some sort. In mobile applications, I've seen a leaky diode in the alternator or a borderline voltage regulator do some nasty things to supply voltage, all the while providing no other indication of a fault. Replacing these components might also help the situation. Floating grounds or ground loops will also wreak havoc.
I am a strong advocate of proper wiring with the proper gauge and connection procedures. However, a seemingly miniscule vehicle deficiency can be attributed to most challenges. The gauge of the wire is SOLELY for current carrying capacity, not EM interference. Actually, the increased surface area of a larger gauge wire causes it to receive MORE external interference, in theory. A "legal" CB only draws a few amps during transmit. The "ground" for the antenna is ground...period. RF and DC ground are the same. The antenna needs a ground plane in order to properly radiate RF energy. A fiberglass or insufficient plane area requires either a base loaded or elevated feed antenna to provide this plane.
The best solution to PERMANENTLY fix Harley's problem if he wanted to maintain "key on" power is to utilize a relay to switch supply voltage when the ignition is turned on and the use of a filter of some sort. This will guarantee a trouble free radio. OR...he could get another unit /forums/images/icons/smile.gif. Ensuring that his MSD box is properly connected would also be advisable...
OK...I'm done. Just my $0.02
I am a strong advocate of proper wiring with the proper gauge and connection procedures. However, a seemingly miniscule vehicle deficiency can be attributed to most challenges. The gauge of the wire is SOLELY for current carrying capacity, not EM interference. Actually, the increased surface area of a larger gauge wire causes it to receive MORE external interference, in theory. A "legal" CB only draws a few amps during transmit. The "ground" for the antenna is ground...period. RF and DC ground are the same. The antenna needs a ground plane in order to properly radiate RF energy. A fiberglass or insufficient plane area requires either a base loaded or elevated feed antenna to provide this plane.
The best solution to PERMANENTLY fix Harley's problem if he wanted to maintain "key on" power is to utilize a relay to switch supply voltage when the ignition is turned on and the use of a filter of some sort. This will guarantee a trouble free radio. OR...he could get another unit /forums/images/icons/smile.gif. Ensuring that his MSD box is properly connected would also be advisable...
OK...I'm done. Just my $0.02