Amateur Radio Station Grounding Plan

Star Configuration with Lightning Protection

For: Paradise, CA (high lightning risk area - post-wildfire)
Configuration: Star ground (single-point ground prevents loops)
Status: Planning complete, ready for installation (January 2026)

Why Grounding Matters

A proper station grounding system serves three critical purposes:

1. Safety: Protects you from electrical shock
2. Lightning Protection: Diverts strikes to ground, protects equipment
3. RFI Reduction: Common ground reduces noise, prevents ground loops

My Navy SIGINT experience taught me that proper RF grounding is similar to shipboard practices: prevent loops, reduce interference, and maintain a single reference point for all equipment.

Star Ground Architecture

                STATION GROUND BUS (6ga copper)
                         |
    ┌────────────────────┼────────────────────┐
    |                    |                    |
[27' Mast]          [Shack Ground]      [Utility Ground]
Lightning            Equipment Ground     House Ground Rod
Arrestors            (radios, SBCs)       (NEC required)
    |                    |                    |
    └────────────────────┴────────────────────┘
                SINGLE EARTH GROUND
               (8' copper rod, <25Ω)
                

Why "star": All grounds connect to ONE central point (ground bus), then single connection to earth. This prevents current loops between different grounds.

Materials List

Budget Tiers

Core Components

Installation Sequence

The installation is broken into four phases. Critically, phases 1-5 can be done NOW (winter 2026), before the mast arrives in spring:

Phase 1: Earth Ground (Do First)

1. Drive ground rod: Use sledgehammer, drive 8' rod to within 6" of surface
2. Test resistance: Ideal <25Ω, acceptable <100Ω
3. Bond to utility ground: NEC requires all grounds bonded together

Phase 2: Ground Bus Installation (Indoor)

1. Mount bus bar: 8' length of 6ga copper, mounted horizontally 4' above floor
2. Bus to earth ground: Run 6ga wire through wall to ground rod outside
3. Label connections: Each lug gets brass tag (e.g., "Coax 1 - Antenna", "Radio Power")

Phase 3: Equipment Grounding

Each device gets its own connection to bus (star topology):

• Transceivers: 10ga wire from chassis ground to bus (<6' wire length)
• Power supplies: Negative terminal to bus
• Coax shield: Bonded to bus at entry point
• Computer/SBCs: Metal case to bus (reduces RFI pickup)

Phase 4: Lightning Arrestors (Outside)

Mount OUTSIDE wall, between mast and shack entry:

[27' Mast]
     |
  [Coax runs down mast]
     |
  [Lightning arrestors] ← Mounted on outside wall
     |                    Ground wire to rod
  [Wall penetration]
     |
  [Shack equipment]
                

Critical: Arrestors must be OUTSIDE, before coax enters shack. This ensures lightning is diverted to ground BEFORE entering your station.

For 27' Telescoping Mast

My planned mast installation (April-May 2026) will include:

• Mast base bonding: Copper strap from mast to ground rod (shortest path)
• Tilt-down feature: Flexible bonding strap stays connected when lowered
• EFHW antenna: Counterpoise wire also grounds to same bus

Testing Procedures

Initial Testing (Before Equipment Installed)

1. Resistance test: Rent ground resistance tester (Fluke 1625, $40/day)
2. Goal: <25Ω (excellent), <100Ω (acceptable)
3. If high: Add chemical treatment or second rod 6' away

After Installation

• Visual inspection: Quarterly check for corrosion (green = bad)
• RFI testing: Measure noise floor with/without equipment grounds
• SWR check: Grounding shouldn't affect SWR significantly (if >0.5 change, check connections)

Lightning Protection Strategy

Direct Strike Protection

The 27' mast with EFHW antenna is the tallest structure, making it the most likely lightning target. The protection strategy diverts strikes to ground:

Lightning → Antenna → Coax → Arrestor → Ground Rod → Earth
                               ↑
                          (bypasses shack)
                

Defense in Depth

1. Primary: Lightning arrestors outside (clamp voltage to ~100V)
2. Secondary: Disconnect antennas in thunderstorms
3. Tertiary: Unplug radios from AC power during storms

California Fire Risk

Post-Camp Fire considerations for Paradise, CA:

• Clear 10' radius around ground rod (bare dirt, no vegetation)
• Ground rod area = defensible space
• Metal mast doesn't burn (safer than wood poles)

Common Mistakes to Avoid

NEC Code Compliance

National Electrical Code requirements:

• Bonding: All ground rods must be bonded together (ham shack → utility ground)
• Rod depth: 8' minimum (or to bedrock if shallower)
• Clamps: Listed for direct burial (bronze or copper, no aluminum)
• Inspection: May need permit in Paradise (check county, post-fire rebuilding regs)

Download Full Plan

The complete station grounding plan (20+ pages) includes:

• Detailed materials BOM with sources and part numbers
• Step-by-step installation instructions with photos/diagrams
• Testing procedures and troubleshooting guide
• Paradise, CA specific considerations
• Maintenance schedule and inspection checklist

Download: station_grounding_plan.md (Markdown format, 16K)

Timeline

Related Projects

• Longwire Antenna Design - EFHW for 27' mast
• Faraday Cage Design - RFI shielding for SDR cluster
• Test Equipment - NanoVNA for SWR testing

73 de Mervyn Martin
Paradise, California