RF Coverage Maps: Create Like a Pro in 3 Easy Steps

Ever wondered how to visualize the RF coverage of a potential repeater site or determine the simplex range from your home station? Whether you’re testing a new antenna setup, planning a repeater installation, or simply curious about your station’s reach, RF coverage maps can provide valuable insights.

The good news is that you can generate these maps quickly and easily using Radio Mobile Online, a free web-based tool created by Roger Coudé (VE2DBE). Designed specifically for the ham radio community, this tool uses advanced propagation models and digital terrain data to simulate radio transmissions between fixed and mobile stations. With just a few steps, you can create highly detailed coverage maps tailored to your specific needs.

What Is Radio Mobile Online?

Radio Mobile Online is a radio wave propagation prediction tool that integrates digital terrain data, land cover information, and population density to simulate radio signal behavior. Utilizing over 200 GB of combined data, it can predict coverage with remarkable accuracy in most areas. However, users in urban environments should note that it doesn’t account for the impact of buildings, which can affect signal reliability.

The tool is highly versatile, supporting frequencies from 10 MHz to 250 GHz, making it suitable for a wide range of amateur radio applications—from VHF/UHF repeaters to microwave links.

Step 1: Create an Account

To get started, visit the Radio Mobile Online website and register for a free account. Registration is quick and straightforward:

Click on the registration link.
Provide your name or callsign and email address.
Submit the form.

Within moments, you’ll receive an email with your login credentials. Once logged in, you’ll have access to the site’s full range of features, including the ability to create and save multiple transmitter sites and coverage maps.

Step 2: Plot Your Transmitter Location

After logging in, select the “New Site” option from the left-hand menu. You’ll see a world map with a red pin representing your transmitter location.

How to Plot Your Location

You have two methods to define your transmitter site:

Manual Input: If you know the precise coordinates of your transmitter site, enter the latitude and longitude directly into the provided fields.
Interactive Map: Drag and zoom the map to locate your desired position, then click to place the red pin. For greater detail, switch to the Satellite View to identify buildings, towers, or other landmarks.

Once the pin is correctly positioned, click “Submit” to save your site.

Step 3: Create an RF Coverage Map

With your transmitter location saved, you’re ready to generate your RF coverage map. Select the “New Coverage” option from the menu. You’ll be prompted to define your station parameters through several input fields.

Key Fields to Complete

Centre Site: Choose your saved transmitter location from the dropdown menu.
Antenna Height: Enter the height of your antenna above ground in meters. (To convert feet to meters, divide by 3.28.)
Antenna Type: Select “Omni” unless you’re using a directional antenna.
Frequency: Specify your transmitter’s operating frequency (between 10 MHz and 250 GHz).
TX Power: Enter your transmitter’s output power in watts.
Line Losses: Include feedline losses for both the transmitter (TX) and receiver (RX) to improve accuracy.
Mobile Antenna Settings: Define the receiving antenna’s height (in meters) and gain (in dBi) for mobile stations.
Maximum Range: Set the analysis range in kilometers. (To convert miles to kilometers, multiply by 1.6.)
RX Threshold: Specify the lowest signal strength to display on the map (e.g., -120 dBm for general sensitivity).

Refinements for Advanced Users

Antenna Azimuth and Tilt: Adjust these settings if you’re using a directional or high-gain antenna to account for its beam pattern.
Required Reliability: Increase this value for a more conservative estimate of coverage in challenging environments.

Step 4: Wait for Processing

After entering your data, click “Submit” to generate the map. Processing can take anywhere from a few minutes to 20 minutes, depending on the complexity of the map and server traffic. Once complete, your coverage map will display as an overlay on the terrain. To save the map, click “Add to my coverages.”

Interpreting Your RF Coverage Map

The coverage map displays areas where your signal is expected to reach based on the specified parameters. Typically:

Green Areas: Stronger signals and better coverage.
Yellow Areas: Weaker signals and marginal coverage.

A sample of the RF coverage maps created using Radio Mobile Online. This one illustrates hypothetical 450 MHz signal strength radiating from the CN Tower in Toronto, Canada; green areas denote strong signal strength, while yellow areas indicate weaker coverage. — A sample of the RF coverage maps created using Radio Mobile Online. This one is showing hypothetical 450 MHz signal strength from the CN Tower in Toronto, Canada. Green areas represent stronger signals, while yellow indicates weaker coverage.

Things to Keep in Mind

Urban Limitations: In densely populated areas, the map may not account for building obstructions, leading to optimistic estimates.
Terrain Influence: Natural features like hills, mountains, and valleys significantly impact signal propagation. Radio Mobile Online’s terrain data helps account for these factors, providing reliable predictions for rural and open areas.

Practical Applications of RF Coverage Maps

RF coverage maps are valuable for various amateur radio purposes:

Repeater Planning: Assess potential sites to ensure maximum coverage for your community.
Simplex Range Optimization: Fine-tune antenna height, power, and gain to maximize your station’s range.
Microwave Links: Visualize point-to-point connections for high-frequency bands.
Event Planning: Determine coverage for temporary stations or emergency operations.

By combining the predictive power of Radio Mobile Online with on-the-ground testing, you can gain a comprehensive understanding of your station’s performance.

Tips for Success

Experiment with Parameters: Small changes in antenna height or power can significantly impact coverage. Test multiple configurations to find the optimal setup.
Compare Maps: Generate coverage maps for different locations to identify the best site for your repeater or station.
Collaborate: Share your maps with fellow hams to gather feedback or plan group projects.

Start Mapping Today!

Creating RF coverage maps has never been easier. With Radio Mobile Online, you have a powerful tool at your fingertips to visualize and optimize your station’s performance. Whether you’re planning a new repeater, testing antenna setups, or exploring your range, this tool can help you make data-driven decisions.

Visit Radio Mobile Online today and start creating professional RF coverage maps to share with your ham community!

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