Why Loop on Ground(LOG) Antennas Are the Secret Weapon for HAM Operators

Have you ever dreamed of setting up a powerful HF antenna system but been thwarted by space limitations or HOA restrictions? What if there was an antenna that offered excellent reception, was virtually invisible to neighbors, and could be installed in even the smallest yards? Enter the Loop on Ground (LOG) antenna – the unsung hero of stealth amateur radio operations that's changing the game for operators worldwide.

In today's increasingly crowded urban and suburban environments, finding space for traditional elevated antennas can seem impossible. Meanwhile, noise floors continue to rise, making clean reception more challenging than ever. The LOG antenna presents an ingenious solution to both problems, providing remarkable performance while remaining practically invisible.

In this comprehensive guide, we'll explore how this ground-hugging wonder works, why it might be the perfect addition to your HAM shack, and step-by-step instructions to build your own LOG antenna this weekend – often with materials you may already have on hand.

What Is a Loop on Ground Antenna?

A Loop on Ground (LOG) antenna is exactly what the name suggests – a wire loop placed directly on or very close to the ground surface. Unlike traditional antennas that rely on height for effectiveness, the LOG embraces its ground-level position as an advantage rather than a limitation.

This horizontal loop configuration creates a unique reception pattern that offers several unexpected benefits. While primarily used as a receiving antenna for HF bands, its near-invisible profile makes it particularly valuable for amateur radio enthusiasts facing space constraints or restrictions on visible antenna structures.

4 Compelling Advantages of LOG Antennas

1. Superior Signal-to-Noise Ratio in Noisy Environments

Perhaps the most remarkable feature of LOG antennas is their exceptional signal-to-noise (S/N) ratio. In today's electromagnetically cluttered world, this advantage cannot be overstated. The physics behind this benefit is fascinating: the ground-level placement naturally attenuates much of the man-made noise that propagates horizontally, while still capturing the desired signals that arrive at lower angles.

For operators in urban or suburban settings plagued by power line noise, switching noise from electronics, and other interference sources, the LOG often reveals signals that would otherwise be buried in noise on conventional antennas. Many operators report being able to copy stations on a LOG that remain completely inaudible on their elevated antennas.

2. Unmatched Stealth Operation

The LOG antenna is the ultimate stealth solution. Lying flat on the ground and typically following property lines or garden beds, it remains virtually invisible to casual observers. For operators dealing with homeowners' associations, restrictive covenants, or simply aesthetic concerns, this invisible profile is game-changing.

You can install a LOG antenna in plain sight, and most people will never notice it's there. The wire can be hidden under mulch, tucked along fence lines, or integrated into landscaping features. Many operators maintain successful LOG installations for years without neighbors ever becoming aware of their presence.

3. Space Efficiency Without Performance Sacrifice

While Beverage antennas (another popular receiving antenna) require substantial linear space – often hundreds of feet – a LOG can deliver comparable performance in a much smaller footprint. A standard square LOG measuring 15-20 feet per side can provide excellent reception across multiple HF bands while fitting comfortably in even modest-sized yards.

This space efficiency doesn't come with significant performance penalties. In fact, within its design parameters, a properly constructed LOG can match or exceed the performance of many larger antenna systems for receiving purposes, especially when noise rejection is the primary consideration.

4. Weather-Resistant Reliability

Unlike elevated antennas that face the full force of wind, ice, and storms, the ground-hugging LOG remains largely protected from weather extremes. This translates to exceptional reliability and minimal maintenance requirements. Once properly installed, a LOG antenna can operate effectively for years with little to no attention required.

This weather resistance makes the LOG particularly valuable as a backup receiving antenna, ensuring you maintain communications capability even when primary antenna systems might be compromised by severe weather events.

How to Build Your Own LOG Antenna: Step-by-Step Guide

Building your own Loop on Ground antenna is a straightforward weekend project requiring minimal specialized tools or components. Here's how to construct a basic LOG antenna that will deliver impressive results across the HF spectrum:

Materials Needed	Tools Required
50-80 feet of insulated wire (14-18 AWG) Isolation transformer (6.25:1 ratio) 75-ohm coaxial cable (length as needed) Weatherproof housing for transformer Landscaping staples (20-30) Coax connectors (appropriate for your equipment)	Wire cutters/strippers Soldering iron and solder Measuring tape Multimeter (for continuity testing) Hammer (for installing landscaping staples)

Step 1: Build the Feedpoint Isolation Transformer

The isolation transformer is critical to the LOG antenna's performance. It matches impedances and isolates the antenna from the feedline, preserving the reception pattern.

1. Select a ferrite toroid core (FT-140-43 or similar works well)
2. Wind 5 turns of wire for the antenna side
3. Wind 2 turns of wire for the coaxial side
4. Secure the windings and solder connections
5. House the transformer in a weatherproof enclosure

If winding your own transformer seems intimidating, several amateur radio suppliers offer pre-built isolation transformers specifically designed for LOG antennas.

Step 2: Plan and Measure Your Loop

Before laying wire, plan your loop's location and dimensions:

1. Select a location away from buildings and large metal objects
2. Measure and mark a square (typically 15-20 feet per side)
3. Consider the location for your feedpoint transformer (ideally at a corner)
4. Ensure your coaxial cable can reach from the feedpoint to your radio equipment

While square configurations are most common, rectangular or delta loops can also work well depending on your available space. The total wire length typically ranges from 60-80 feet for general HF reception.

Step 3: Lay and Secure the Wire

With your plan in place, it's time to install the antenna:

1. Cut your insulated wire to the planned perimeter length plus a few extra feet
2. Lay the wire following your marked perimeter
3. Secure the wire with landscaping staples every 18-24 inches
4. Ensure the wire maintains ground contact around the entire loop
5. Leave sufficient wire at the feedpoint corner for connection to the transformer

If aesthetics or protection are concerns, the wire can be placed under a thin layer of mulch or ground cover. Just ensure the covering doesn't raise the wire significantly above ground level.

Step 4: Connect the Transformer and Feedline

The final step connects your antenna to your receiving equipment:

1. Strip and connect the loop ends to the transformer's antenna terminals
2. Connect your coaxial cable to the transformer's feedline terminals
3. Secure the transformer housing in position
4. Route the coaxial cable to your radio equipment
5. Ground the coaxial shield at your building entry point for safety

Optimizing Your LOG Antenna Performance

Once your basic LOG antenna is installed, consider these optimization strategies to maximize its performance:

When to Consider a Preamplifier

For most HF bands (especially 40 meters and higher), a LOG antenna provides sufficient signal strength without additional amplification. However, on lower bands like 160 meters or when attempting extremely weak signal reception, a preamplifier can significantly improve performance.

If you decide to add a preamplifier:

• Place it as close to the antenna feedpoint as practical
• Ensure it has sufficient overload protection for your environment
• Use a preamplifier specifically designed for receiving applications
• Consider a remotely switchable model to engage only when needed

Scaling Up: Larger Loop Dimensions

While the standard 15-20 foot per side LOG works well as a general-purpose receiving antenna, scaling up the dimensions can enhance performance on specific bands:

• 160 meters: Consider expanding to 30-40 feet per side
• 80 meters: A 20-30 foot per side loop provides excellent results
• 40 meters and up: The standard 15-20 foot dimensions work extremely well

Remember that increasing the loop size beyond one wavelength at your highest frequency of interest can create unpredictable pattern changes. For multi-band operation, finding the optimal compromise size is key.

Directional Considerations

The standard square LOG exhibits a bi-directional pattern, with maximum sensitivity perpendicular to the sides of the square. To optimize reception from specific geographic areas:

• Orient the sides of your square to align with your primary areas of interest
• Consider installing two LOG antennas in different orientations with a switch to select between them
• Experiment with rectangular shapes to emphasize certain directions

Real-World Results: What to Expect

After installing your LOG antenna, you might be surprised by what you hear – and don't hear. Many operators report:

• Significantly reduced noise floor compared to elevated antennas
• Ability to copy weak DX stations that are buried in noise on other antennas
• Consistent performance regardless of weather conditions
• Unexpected reception of signals from surprising distances, especially during quieter band conditions

The LOG particularly shines during contests and crowded band conditions, where its noise rejection capabilities help separate desired signals from the cacophony. While primarily a receiving antenna, some operators have reported success using a LOG for low-power QRP transmissions, though this is not its primary design purpose.

Conclusion: The Invisible Advantage

The Loop on Ground antenna represents a perfect balance of performance, stealth, and simplicity. In an era where space constraints and aesthetic concerns increasingly limit amateur radio operations, the LOG offers a powerful alternative that requires minimal resources yet delivers impressive results.

Whether you're battling severe noise issues, facing antenna restrictions, or simply looking to expand your receiving capabilities, a LOG antenna deserves serious consideration. Its combination of excellent signal-to-noise ratio, unobtrusive profile, and simple construction makes it accessible to operators at any experience level.

The next time you hear someone lamenting that they "don't have room for a proper antenna," introduce them to the Loop on Ground. This humble wire on the soil just might reveal signals they never knew were there – hiding in plain sight, just like the antenna itself.