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Throughout my many years in the world of amateur radio, one topic that has continually fascinated me is the evolution of antennas, particularly the HF Ground Plane vertical antenna. Having been licensed since 1960, I've witnessed firsthand how the usage and placement of this antenna have shifted dramatically over time. In this article, I want to explore the historical context of the HF Ground Plane, compare its traditional use with contemporary practices, and invite you to consider whether the way we currently deploy these antennas is truly the best approach.
The Journey Back to the Early Days of Vertical Antennas
When I first entered the hobby back in 1960, my setup was quite modest. Living with my parents, I was fortunate enough to have a large garden, which allowed me to use a long wire antenna combined with an antenna matching unit. This setup worked well given my limited budget at the time. However, as life progressed—especially after getting married and moving into a smaller garden—using an inverted wire antenna became less practical.
This led me to explore vertical antennas, which were a popular and effective option, especially when space was at a premium. I eventually acquired a High Gain 14 AVQ vertical antenna, which covered the 40 to 10 metre bands—back then, we didn't have the wide range of bands available today. This antenna was well-regarded, and the manufacturer was eventually acquired by MFJ, who unfortunately have since ceased production of this particular model.
Traditional Installation: Elevated Vertical Antennas
One of the most striking differences between past and present use of vertical antennas lies in where and how they were installed. Traditionally, vertical antennas like the High Gain 14 AVQ were mounted high up—often on rooftops or at the end of a roof ridge. Radials were carefully laid out on the roof tiles or slates, which acted as natural insulators, and were run down at a 45° angle. This careful positioning allowed for an excellent match with 50-ohm coaxial cable and resulted in impressive performance.
Manufacturers at the time warned against mounting vertical antennas on the ground unless there was no alternative. This advice was given because ground mounting introduced several problems, including increased noise and poorer signal propagation.
Why the Shift to Ground-Mounted Verticals?
Fast forward to today, and the majority of vertical antennas are installed on or near the ground, especially in urban or suburban settings where space is limited. This shift raises several important questions. Are we using vertical antennas to their full potential? Or have convenience and common practice overshadowed optimal installation methods?
Let’s consider some of the implications of ground mounting:
- Reduced Sky Visibility: Vertical antennas mounted close to the ground are obstructed by buildings, trees, and other objects, limiting their ability to 'see' the sky. This reduces signal reach and overall performance.
- Increased Noise Levels: Noise in radio communications has both horizontal and vertical components. The vertical component propagates further as ground wave noise, which means vertical antennas close to the ground tend to pick up more noise, degrading the signal-to-noise ratio.
- Loss of Performance: Elevated vertical antennas typically perform better due to reduced noise and better radiation patterns. Ground-mounted antennas often suffer from signal attenuation and less efficient radiation.
Despite these drawbacks, many operators mount verticals on the ground simply because it’s easier or sometimes the only practical option available. But is this the best we can do?
The Benefits of Elevating Vertical Antennas
From my personal experience over the last 10 to 15 years, raising a vertical antenna even a couple of metres above ground level can make a significant difference. At three different locations here in Essex, I experimented with my vertical antenna placed at various heights. When elevated approximately 2 metres above the ground, I noticed substantial improvements in signal clarity and overall reception.
Imagine the potential performance gains if the antenna could be raised even higher—say 4 to 5 metres or more. The benefits would likely include:
- Lower Noise Reception: By elevating the antenna, you reduce the vertical noise component, improving signal-to-noise ratio.
- Better Radiation Patterns: Elevated verticals can achieve a more omnidirectional radiation pattern with less ground loss.
- Improved DX Performance: Historically, operators like Pat Hawker (G3VA) noted that vertical antennas in the air seemed to excel during summer evenings for DX contacts, a phenomenon that might be linked to better propagation conditions and lower noise.
Reconsidering the Vertical Antenna’s Role in Modern Ham Radio
The question remains: why have we largely abandoned the elevated vertical antenna in favour of ground mounting? Is it simply a matter of convenience, or have we lost sight of the antenna’s true potential?
There is a certain irony in how the advice from decades ago—to elevate vertical antennas whenever possible—has been largely reversed in practice today. Many operators now accept ground mounting as the norm, possibly due to space constraints or a desire to blend antennas discreetly into their surroundings.
However, this raises an important point: if you have the option, why not elevate your vertical antenna? Even a modest increase in height can yield substantial benefits. If you have a roof or a structure where the antenna can be mounted, consider installing the radials on the roof surface, running them at an angle to optimize impedance matching.
Challenges of Elevated Vertical Installation
It’s important to acknowledge that mounting vertical antennas in elevated positions is not always straightforward. Rooftop installations may require:
- Permission from property owners or local authorities
- Ensuring the structure can safely support the antenna
- Proper weatherproofing and lightning protection
- Careful radial placement to avoid damage to roofing materials
Despite these challenges, the historical evidence and practical experience suggest that the benefits outweigh the difficulties, especially for serious operators seeking optimal performance.
Reflecting on the Past to Improve Our Future
Looking back at the way vertical antennas were used in the 1960s offers valuable lessons. Back then, operators were more conscious of antenna placement and the impact it had on performance. The HF Ground Plane, essentially an elevated vertical antenna, was a firm favourite. Its popularity was not just because of convenience but because it worked exceptionally well.
Today, as we look to the future of amateur radio, there is merit in revisiting these traditional practices. Elevating vertical antennas can still provide an edge in performance, especially in noisy urban environments where every decibel counts.
Final Thoughts: Where Should We Mount Our Vertical Antennas?
Ultimately, the decision on where to place your vertical antenna depends on your unique circumstances. If you have no alternative but to mount it on the ground, rest assured that it is better than having no vertical antenna at all. However, if you do have options, I urge you to consider elevating your antenna to reduce noise and improve signal propagation.
"Are we using the vertical to its best ability? Are we erecting it in the right way or are we losing something? Why did most people use verticals in the air back in my day, and why now do people tend to put them on the ground?"
These are questions worth pondering as we continue to refine our ham radio setups. I invite you to share your experiences and opinions on vertical antenna placement. Together, we can explore the best ways to harness the full potential of these historic yet still highly relevant antennas.
Additional Resources and Offers
For those interested in upgrading or acquiring a quality HF transceiver to complement your antenna setup, consider the Yaesu FT710. It’s an unbeatable budget-class HF transceiver, currently available with a cashback offer of £85 and part exchange options. Check out your local ham radio store or visit UK Ham Radio Store for more details.
As always, I encourage you to experiment, share your findings, and keep the spirit of amateur radio alive by learning from both the past and the present.