See The Real World Of RF Signals With DADA v3.3

For Amateur Radio operators and RF engineers, the question is always the same: “Will my signal make it?”

For decades, we relied on theoretical calculators. We punched in the numbers, assumed the earth was a smooth sphere, and hoped for the best. But reality is messy. Reality has skyscrapers, mountain ranges, and atmospheric changes.

Enter DADA1 v3.3, a real-world signal simulator developed by Jojo (E25VBE) that doesn’t just calculate—it investigates.

The Problem with “Perfect” Theories

Standard link budget calculators often fail to explain real-world phenomena. Why does a signal flutter uncontrollably in a specific area of Bangkok? Why can’t a station in Bangkok reach Nakornratchasima despite having the power to do so?

The answer lies in the obstacles we usually ignore.

DADA1 v3.3 bridges the gap between theory and reality by treating the environment as it actually exists. Instead of assuming a flat path, it utilizes High-Resolution Sampling (batch fetching data at 200 points). This allows the tool to “see” the sawtooth pattern of city skylines and the rugged peaks of mountains that block your path.

Under the Hood: A Physics Engine for Ham Radio

This isn’t just a distance calculator; it is a full-fledged risk assessment tool for your signal.

• Cumulative Building Loss: It accounts for the concrete jungle, calculating how much signal is lost punching through urban environments.
• The K-Factor (Atmospheric Refraction): The tool adjusts for how the atmosphere bends radio waves (Standard vs. Ducting), giving you a realistic prediction of the radio horizon.
• Fresnel Zone Analysis: It visualizes whether your signal has enough clearance or if “earth bulge” and obstacles are eating into your link margin.

By integrating ITU-R P.526 standards for diffraction loss, DADA1 transforms the S-Meter prediction from a “guess” into a reliable data point for planning emergency communication systems.

A 45-Year Journey: The Legend of DADA

The technology is impressive, but the story behind it is inspiring. The “Legend of DADA” didn’t start in a modern cloud server; it started in 1979 with a childhood dream.

From seeing an Icom 2N at school to marveling at a rotator controller in a basement, E25VBE dreamed of a computer that could control antennas. The journey spanned decades:

1. The Early Days: Writing BASIC on paper in 1979 and coding on Apple IIs.
2. The Spark: A walk through the Ban Mo market in 2008 re-ignited the radio passion, leading to a hunt for towers and multi-beam antennas.
3. The Evolution: Leveraging a background in GPS and mapping, the project evolved from Foxbase to VB.NET, and finally to the modern Web App we see today.

DADA1 is the result of a “Growth Mindset”—a project that survived changing programming languages and decades of technological shifts because the goal remained clear: Automation and Precision.

The Future: Cognitive Radio

DADA1 is just the beginning. The roadmap includes DADA2 (Antenna Automation via ESP32) and DADA3, which aims to implement Cognitive Radio concepts—using real-time RSSI feedback loops to automatically aim antennas at the strongest signal source.

Try It Yourself

Whether you are debugging a repeater link, planning a DX expedition, or just curious why your signal drops near the city center, DADA1 v3.3 is the tool you need.

Challenge: Try setting Point A and Point B to cut through a major landmark (like the Petronas Towers or a local mountain range) and watch the height chart generate the obstruction. It’s a fascinating look at the invisible world of RF.

Analyze your path now: https://dada1.decem.co.th/33.html

Special thanks to Jojo (E25VBE) for his dedication to the community and for sharing this powerful tool.