Chordal Hop is a fascinating and somewhat mysterious phenomenon in the world of ham radio. It's not about music, even if the name might suggest it! Instead, it refers to a unique form of radio propagation that allows signals to travel vast distances with minimal loss. In this blog post, we’ll delve into what Chordal Hop is, how it works, and how you can listen to live signals from remote locations like New Zealand.
What is Chordal Hop?
At its core, Chordal Hop is a method of signal propagation on the high-frequency (HF) bands that can enable radio signals to traverse halfway around the world. This is achieved with surprisingly little loss, making it an intriguing subject for radio enthusiasts. The essence of Chordal Hop lies in its efficiency; it differs from other forms of propagation that often suffer from signal degradation over long distances.
To understand Chordal Hop better, we need to explore how radio signals travel through the ionosphere, particularly focusing on the F2 layer. This layer is crucial for long-distance communication, as it can reflect radio waves back to Earth, allowing them to cover extensive distances.
The Basics of Radio Propagation
When we talk about radio propagation, we refer to how radio waves travel from one point to another. Various factors influence this, including the frequency of the signal, the time of day, and the conditions of the ionosphere. Chordal Hop operates primarily on the HF bands, which are known for their ability to support long-distance communication.

Image reference: Apollo
Signals using Chordal Hop typically ascend to the F2 layer, bounce around, and then return to Earth at distant locations. This process differs from multi-hop propagation, where signals may bounce multiple times before reaching their destination, often losing strength along the way. Chordal Hop, by contrast, appears to favor long paths to antipodes, which are points directly opposite each other on the globe.
Listening to Chordal Hop Signals
So, how can you experience Chordal Hop in action? One of the best ways to listen to live Chordal Hop signals is by tuning into operators who are known to use this method effectively. A prime example is Brian, ZL3XDJ, located in the southern part of New Zealand. Over the past year, many have tuned into his signals, which are remarkably strong and consistent.
Brian operates mainly on the 20m and 40m bands, often during the early morning hours in New Zealand, which coincides with dusk in the UK. This timing is significant as it allows operators in Europe to hear his signals just as they are waking up. The phenomenon of the “gray zone” plays a crucial role here, where signals are particularly strong and clear.
How to Tune In
To listen to Brian and others on the Chordal Hop path, you can use the Reverse Beacon Network. Here’s a step-by-step guide:
- Go to your preferred search engine and type in “Reverse Beacon DX.”
- Once on the site, you’ll see a search box where you can enter a call sign. Type in ZL3XDJ.
- This search will yield a report showing Brian's CQ calls and which stations are receiving them.
- Note the frequency he’s transmitting on, then set your transceiver to that frequency.
- Be patient; there may be a slight delay in the reporting, so he might already be in a QSO by the time you see the report.
Additionally, you can visit QRZ.com to check Brian’s logbook, which will provide further insight into his current operating band and activity.
Understanding Signal Path and Strength
One of the most fascinating aspects of Chordal Hop is the unique signal path it follows. Unlike traditional propagation methods, where signals might be detected at various halfway points along their journey, Chordal Hop signals seem to travel directly to their endpoints, skipping intermediate stops. This is evident in the charts that track Brian’s signals from New Zealand to Europe, showing no signals being propagated anywhere along the way except at their destination.
Brian primarily operates using Morse code (CW), which is an effective mode for long-distance communication, especially when signal strength is marginal. The Reverse Beacon Network is an invaluable tool for monitoring these signals, allowing you to see which stations are successfully receiving his transmissions and the strength of those signals.
Exploring Other Bands
While 20m and 40m are the primary bands for Chordal Hop, it's worth exploring other frequencies as well. Brian has noted that the 15m band sometimes opens up, particularly when the 20m band closes, providing additional opportunities for contact. It’s essential to keep an ear out for these openings, as conditions can fluctuate rapidly.
The Role of Antennas
A key factor in successfully utilising Chordal Hop is the type of antenna used. Brian employs a vertical antenna with four radials, which is elevated about two meters above the ground. This setup is crucial for achieving the necessary angle of radiation to facilitate effective signal propagation. Even in smaller gardens, simple dipole antennas can work wonders if positioned correctly.
Conclusion: The Adventure of Chordal Hop
Chordal Hop represents an exciting frontier in ham radio propagation. While we have learned a great deal about how signals travel, there remains much to explore. As amateur radio operators, there’s always room for discovery, and each new contact can unveil more about the intricacies of radio communication.
As we continue to experiment and gather data on Chordal Hop, we encourage you to participate in the exploration. Whether you're tuning into Brian's signals or experimenting with your own setups, the world of ham radio is full of possibilities. Embrace the adventure, and you might just uncover the magic of Chordal Hop for yourself!
Thank you for your support of the ham radio community. Keep exploring, and we look forward to sharing more insights with you in future discussions!
For more information please visit our online store or alternatively contact us and our team will be happy to assist you!