So finally, here is where Im lost. My homes AC service main panel bonded to the AC main service ground rod. The AC outlet where my radio gets its power has a ground wire going to my AC panel which is bonded to that ground rod. What is the point of running a parallel line from the AC main ground rod to my radio??? (Isnt this STILL a ground loop with 2 different paths to the ground?)
No, not at all; the green wire in your wall receptacle is a dedicated AC equipment ground isolated from DC equipment ground. You are no longer between two earth grounds; you have a single-point connection to the earth.
A common myth is ground rods are at zero voltage—complete BS. If you drive a ground rod and then another rod some distance away, you will have a voltage difference between the two rods you can measure with a DVM and oscilloscope. Connect an oscilloscope to measure lower power frequencies, and you will see 60-Hz because the utility uses the earth as a return conductor using a multi-grounded neutral distribution system. Turn the sweep speed up, and you will see a mish-mosh of noise from cosmic radiation.
Most hams bring the coax directly to the schack, sink a rod or two, and bring it inside. Then you use your radio system to bond the two ground systems together. You do not have a ground because you are in a ground loop, a series of daisy-chained grounds. Your radio system is just a wire bonding the two ground rods together. Those two rods are at a different potential acting as a signal source driving common mode current through the equipment ground plane. Every piece of equipment has a difference of potential because it is a series connected to ground with a common mode current flowing through the equipment ground plane. Could you think of how it is all connected? Your coax enters and carries an earth ground on the coax shield from the rod outside the shack > shield of the coax to tuner chassis > tuner chassis to radio chassis > radio chassis to DC negative > DC negative to DC power supply chassis (you can fix that) > DC power supply chassis to AC equipment ground, AC equipment ground to AC service ground connection. It is a series mess connected in a daisy-chain fashion. Each series segment, coax shield, equipment chassis, or conductor has a series impedance with a common mode current flowing through it from external forces. Simple ohm s law; current x resistance = voltage. Every piece of equipment is at a different potential.
That is just a nuisance in normal operations, especially when you PTT and that long bonding jumper you ran through your house is within two wavelengths magnetically coupled to the antenna, giving you many common mode current problems to fix. The real problem is the danger you have placed yourself in. You need to read up and understand Step Potential created by lightning and utility high voltage faults. When lightning strikes and enters the earth, it discharges along its surface laterally, like throwing a rock in the water. As the currents flow through dirt, a voltage gradient is developed along the way called Step Potential because the distance between your feet is enough to kill you. Depending on the strike's intensity, 1000 to 5000 volts per foot. How far apart is your shack ground from your service ground? How many volts are across your radio system, and how much current is flowing? The answer is 1000's. For current to flow, there must be a point of entry and a point to exit. You provided a path through your home for lightning to enter and exit—the Father of common mode current.
Back to your question: Yes, you need a dedicated ground conductor for the Station Ground; it is required and cannot be the AC equipment ground from a receptacle. You would lose isolation between AC and DC systems if you did that. You need a dedicated station ground conductor for two reasons: Safety and Operational. Starting with safety, NEC requires electrical systems to be isolated, like AC and DC power systems. The reason is simple: if there is a line fault to the ground in one of the systems, the fault current is contained in that system and not the other minimizing electrical shock and equipment damage. Code requires both systems to have a common ground point in the event there is a cross-system fault, AC to DC to provide a PLANNED FAULT path back to the source. Your radio system is a 12 -Volt DC low voltage system and requires a dedicated DC Equipment Ground, aka DCEG. Convert that to ham lingo, your Station Ground.
Operationally this is where hams get lost in elmer's tall tales. AC ground is dirty is a half-truth. The AC Service ground is NOT DIRTY; the AC Equipment Grounds, aka ACEG, can be dirty (noisy). The AC service ground is misunderstood; it is the point where the AC service is bonded to the premises ground electrode system, aka GES. It is a single-point connection via a specific conductor called the ground electrode conductor, aka GEC. The GEC is the conductor running from your service disconnect device like a meter can straight down to the GES. It is the GES you may want to supplement because Mr. Sparky did the code minimum; he drove two ground rods 6-feet apart, collected a check, and called it a day. The best practice is to run a solid, bare, tinned, 6 AWG minimum copper conductor in the same trench as the coax below it as deep as possible to the tower. Otherwise, run away from the house or protected area to direct lightning away. Rods are for power frequencies; radials are for lightning, and longer is better.
ACEGs are the third wire run with your AC branch circuits to wall receptacles, and the ACEGs originate where the GEC is bonded to the Service Neutral Conductor inside your service disconnect device. So how does the ACEG get noisy or dirty? Again, it is straightforward. All equipment plugged in has passive electrical devices installed between Line to ACEG and Neutral to ACEG to meet FCC requirements and over-voltage protection. For example, line filters, PFC correction circuits, capacitors, gas discharge tubes, SADs, and MOVs. That dumps RF and low-level 60-Hz line current into the ACEG, corrupting the ground circuit. Ever heard a hum in PA speakers? The best solution to MINIMIZE the problem is to run dedicated AC branch circuits to the shack. You will not have upstream or downstream receptacles daisy-chained together, adding to the noise. If there is any noise on the ACEG, it is because whatever you plugged in generates it. All your home branch circuits have dedicated and isolated ACEGs, so noise or a fault in one circuit will not interfere with other branch circuits.
So yes, you want your station ground to originate where your AC service ground originates, the same single point that all ground systems originate from. Your earth ground, lightning ground (antenna discharge units), AC ground, and DC ground all connect at the same point. The DCEG and ACEG that go inside are an open circuit going nowhere. The best place is to tap the GEC as close as practical to the service disconnect device. Everything at the same volage potential. with no current flowing. A ZERO-VOLT reference POINT. If there is no voltage or current = no noise and safe.
How is that for a Jack Wagon?
.