These are not exotic use cases. They come up constantly. Yet the tools to answer these questions are scattered across multiple apps, websites, and calculator windows. That changes with the 9M2PJU Amateur Radio Bearing Finder, a free web app built specifically for ham radio operators at bearing.hamradio.my.

What It Does

The app combines four things that ham operators regularly need into a single, map-backed interface:

• Compass bearing and great-circle distance between any two points on Earth
• Free-space path loss and terrain-adjusted path loss for the link between your location and the destination
• Estimated signal strength based on your transmit power and antenna height
• QSO probability based on the link budget
• Maidenhead grid square calculation for both ends of the path, useful for contesting and logging

You enter your coordinates (or tap “Get My Location” to pull them automatically via GPS), then either search for a destination by name or enter coordinates manually. The map draws the bearing line, and the radio calculation panel fills in the numbers instantly.

Situations Where This Is Actually Useful

Contesting and grid chasing. During contests like CQ WW, IARU HF, or any Maidenhead grid exchange contest, you need to know your grid square and your contact’s grid square. The app shows both instantly and calculates the great-circle distance, which matters for distance multipliers in some contests.

Antenna aiming for DX. If you’re running a beam, a yagi, or a directional wire, you need to know what bearing to set. Pointing a 3-element yagi in the wrong direction by 20 degrees can cost you several dB. Put in your shack’s coordinates and the DX station’s location, read the bearing off the compass rose, done.

SOTA and POTA planning. Before heading out to an activation summit, you want to know whether a path to a particular station, club, or reflector is line-of-sight viable. Entering the summit coordinates and the destination lets you see the distance and a rough path loss estimate, which helps you decide whether a 5W handheld is enough or whether you need to pack the bigger rig.

APRS path planning. When setting up a digipeater or iGate, operators often want to understand the theoretical coverage radius for a given height and power. The path loss calculator gives you a quick sanity check before you climb the tower.

EMCOMM deployment. During emergency communications activations, you may need to quickly determine whether a direct simplex link to another station or a served agency is feasible. Knowing the free-space path loss and comparing it against your expected receiver sensitivity gives you a realistic answer fast, without guessing.

Learning propagation basics. For newer licensees, the app’s formula display makes it a teaching tool. Free-space loss, the Friis transmission equation in simplified form, and the relationship between frequency, distance, and received power are all shown and explained. Punch in different frequencies and watch how path loss changes. It reinforces what the handbooks teach.

DXpedition tracking. When a rare DXCC entity comes on the air, you want to know what direction to beam toward them. Search the destination by name or enter the island/entity coordinates and the bearing is on screen immediately.

The Technical Side

The path loss calculation uses the standard free-space formula: 32.44 + 20log(f) + 20log(d), where f is frequency in MHz and d is distance in kilometres. On top of that, the app applies a terrain factor to estimate real-world path loss, which will be higher than free space in almost every practical situation.

Signal strength is computed from your entered transmit power in dBm, minus total path loss, plus an antenna gain factor based on the height you input. The QSO probability figure is a heuristic derived from that link budget, not a guarantee. It’s a planning tool, not a propagation prediction engine. For serious HF propagation forecasting you’d use VOACAP or similar. But for a quick sanity check before a VHF contest run or a UHF simplex attempt, the numbers are solid.

Grid square calculation follows the standard Maidenhead locator system and resolves to six-character precision, which is the level most contest exchanges use.

Try It

Point your browser to bearing.hamradio.my, allow location access, and search for any callsign’s home country or a summit you’re planning to activate toward. The bearing, distance, grid squares, and link budget are there in under five seconds.

It is free. It works on mobile. And it was built by a ham, for hams.

73 de 9M2PJU

The post 9M2PJU Amateur Radio Bearing Finder: A Practical Tool for Ham Radio Operators appeared on Hamradio.my - Amateur Radio, Tech Insights and Product Reviews by 9M2PJU.