Mashurst
Adventurer
Background for those that may not know:
Unlike most 12v things in a vehicle a radio requires particular attention to grounding such as a fuse in the ground line and a solid copper path back to the core of the vehicles charging system. The reason for this is that should the vehicles own ground path be disrupted for any reason such as a failure of the ground strap, the path of least resistances may be through the jacket of the radios antenna coax. This path tends to be destructive to the radio. Most radio manufacturers recommend in their manual that the radio be wired directly to the battery positive and negative terminals with a fuse in each line.
The question:
Is the negative battery post the best ground location in terms of protecting the radio? If the main vehicle chassis ground (that is the wire from the battery to the body) were to become intermittent or fail in any way. It seems unlikely that the ground line fuse would blow fast enough to protect the delicate semiconductor type components in a modern radio transceiver. A fellow on the local repeater was asserting last night that grounding the radio to the vehicles main chassis ground point would somehow solve this problem. He said Motorola and other commercial types recommend chassis ground at some kind of ground node rather than battery ground. I didn’t get a clear understanding of what his rational was but it does seem logical that if the failure of the vehicle ground system that was threatening the radio happened to be a bad connection at the main chassis ground the radio would be losing its ground at the same time thus elimination it as a possible ground loop thru the coax. Barring that narrow scenario however and assuming a ground short could happen in any number of other places it seems only marginally better. An electrical engineer friend has also told me that I should connect the radio ground wire to the chassis near the radio in addition to the wire back to the battery/main chassis ground point.
My setup:
The negative post on my battery has two large wires, one that runs to the unit-body and one to the starter. There is also a strap from the engine to the body. This forms a ground triangle where any single line could fail and I would still have some kind of ground. My radio is on an auxiliary 8 gauge circuit that I added that connects to the battery lugs per my radios manual. It has a self-resetting breaker near the battery connection only on the positive side and then runs through the firewall where it splits into 4 pairs of Anderson power poles. I plug the radio into one of these power poles with the stock wires and the OEM duel fuse arrangement.
So what do you think? Would it be a good idea to move the ground wire for my aux circuit from the battery post to the body end of the wire that goes from the battery to the body? What about a second body ground inside the cab for this aux circuit?
Unlike most 12v things in a vehicle a radio requires particular attention to grounding such as a fuse in the ground line and a solid copper path back to the core of the vehicles charging system. The reason for this is that should the vehicles own ground path be disrupted for any reason such as a failure of the ground strap, the path of least resistances may be through the jacket of the radios antenna coax. This path tends to be destructive to the radio. Most radio manufacturers recommend in their manual that the radio be wired directly to the battery positive and negative terminals with a fuse in each line.
The question:
Is the negative battery post the best ground location in terms of protecting the radio? If the main vehicle chassis ground (that is the wire from the battery to the body) were to become intermittent or fail in any way. It seems unlikely that the ground line fuse would blow fast enough to protect the delicate semiconductor type components in a modern radio transceiver. A fellow on the local repeater was asserting last night that grounding the radio to the vehicles main chassis ground point would somehow solve this problem. He said Motorola and other commercial types recommend chassis ground at some kind of ground node rather than battery ground. I didn’t get a clear understanding of what his rational was but it does seem logical that if the failure of the vehicle ground system that was threatening the radio happened to be a bad connection at the main chassis ground the radio would be losing its ground at the same time thus elimination it as a possible ground loop thru the coax. Barring that narrow scenario however and assuming a ground short could happen in any number of other places it seems only marginally better. An electrical engineer friend has also told me that I should connect the radio ground wire to the chassis near the radio in addition to the wire back to the battery/main chassis ground point.
My setup:
The negative post on my battery has two large wires, one that runs to the unit-body and one to the starter. There is also a strap from the engine to the body. This forms a ground triangle where any single line could fail and I would still have some kind of ground. My radio is on an auxiliary 8 gauge circuit that I added that connects to the battery lugs per my radios manual. It has a self-resetting breaker near the battery connection only on the positive side and then runs through the firewall where it splits into 4 pairs of Anderson power poles. I plug the radio into one of these power poles with the stock wires and the OEM duel fuse arrangement.
So what do you think? Would it be a good idea to move the ground wire for my aux circuit from the battery post to the body end of the wire that goes from the battery to the body? What about a second body ground inside the cab for this aux circuit?
