The Holy Cluster is a modern web-based DX cluster for amateur radio operators. It plots live worldwide spots on an interactive map, making DX (long-distance contact) hunting more intuitive than traditional text-based cluster
Developed by a team of Israeli hams and supported by the Israeli Association of Radio Communication (IARC), additionally it shows active stations as map pins that include callsign, frequency, mode and other details in real time.
Key Features
- Interactive Global Map: A live world map shows incoming DX spots as pins. Each pin reveals the station’s callsign, frequency, mode (SSB, CW, FT8, etc.), timestamp and notes, giving a visual “snapshot” of current activity.
- Color-Coded Band Overview: Bands are color-coded on the map and band bar, so you instantly see which HF bands are open and where stations are active. This makes it easy to spot DXpeditions or contest activity at a glance.
- Advanced Spot Filtering: Robust filters let you narrow spots by band, mode, continent/country, or even callsign prefix/suffix. You can isolate rare regions or modes, hide self-spots (portable stations), and toggle filters on/off without reconfiguring.
- Custom Alerts: Set up alerts for specific DXCC entities or callsigns so you never miss a rare station. The Holy Cluster can notify you when a target appears, ensuring you catch fleeting openings.
- Intuitive UI: The site uses a clean, responsive design that works on desktop and mobile. It offers features like dark mode and a “band bar” frequency display for each band. Auto-zoom keeps all spots in view as they appear, and you can sort the spot table by any column for easier reading.
- Live Logging/CAT Support: Integration with a lightweight “CAT Server” means you can click a spot to tune your radio (via compatible software). This bridges The Holy Cluster with your transceiver, streamlining your workflow.
- Open Source & Community-Driven: The Holy Cluster is fully open-source and free. Its code is on GitHub (iarc-il/HolyCluster), and developers actively incorporate user feedback into updates. Because it’s maintained by radio amateurs for radio amateurs, new features roll out quickly to meet hams’ needs.
Benefits for Operators
The Holy Cluster makes DX chasing easier and more engaging. Including visualizing spots on a map, so you can instantly identify where signals are coming from and spot unusual activity (like a rare DXpedition) as it happens.
Furthermore, then have color-coded band views and propagation data to help you pick the right band or mode at the right time. The filtering and alert features mean you only see the signals you care about, saving you from wading through irrelevant spots.
Many users report that these features “bring DXing back” and add excitement to everyday monitoring. Compared to classic telnet clusters or simple web lists, The Holy Cluster feels like a real-time radio control center. It highlights band openings graphically and even pulls in SOTA/POTA activators along with DX, giving a comprehensive picture.
The result is a more intuitive experience that draws users back on air. As one ham put it, it’s a “fresh, intuitive way to engage” with the amateur bands.
Unique Capabilities
Several aspects set The Holy Cluster apart from other spotting tools:
- Graphical Navigation: Instead of just scrolling text, you see spots on a map. You can rotate or zoom the world map to concentrate on any region. An optional equator line toggle aids studies of rare propagation modes (like transequatorial paths).
- Real-Time Interactivity: The interface links the map, band bar and spot table. Select a spot in one view and it highlights everywhere, this integration is rare in DX tools. You can also submit new spots directly through the app, turning every user into a potential spotter.
- Precision: Spots are logged with 100 Hz frequency resolution and can display country flags or names at your choice. Auto-zoom and a center-dot indicator help you never lose context.
- Customization: Things like Dark Mode, unit switching (km/miles), and instant band highlighting (hover over a band to see its activity) all add polish. Most importantly, the tool is free and user-supported, with regular updates rolled out via GitHub feedback
Access and Download
There’s no software download needed, it runs entirely in your browser. For those interested in the internals or running a private instance, the code is available on GitHub (iarc-il/HolyCluster) under an open-source license. The project is maintained by volunteers in the IARC community, and it will always remain free to use.
Community Feedback and Reputation of The Holy Cluster
Since its launch in late 2024, The Holy Cluster has earned a strong reputation among hams. A DXZone resource entry calls it “a modern ham radio DX cluster with a real time graphical map” and even awarded it a perfect rating of 10/10 from community votes. On QRZ.com’s forums, experienced operators have praised it as “very impressive” and are excited to adopt it.
Users note that it’s already outperforming older clusters in usability, one user said the default filters give “a nice mix of POTA, SOTA, and DX” and that the tool is “drawing [him] back in” to DXing. Ham Radio Weekly even listed The Holy Cluster as a top link in its news roundup.
In short, The Holy Cluster is hailed as a game-changer. Its modern interface and features have convinced many in the community that it’s “the best” DX spotting tool available. If you’re a contester, casual DXer, or club operator, it’s worth checking out for a fresh way to explore the bands.