Guide
Radio Mobile alternative for two-way radio dealers and integrators
Stolz Telecom · October 4, 2026
Radio Mobile is the coverage program most people in two-way radio have run at least once: free, built on Longley-Rice, and good at what it sets out to do. This guide sets it beside Sentinel RF fact for fact, so a dealer deciding what to run can see where the free tool is enough and where it leaves the rest of the job to you.
What Radio Mobile is, and who it is for
Radio Mobile is a radio propagation prediction program written and maintained by Roger Coudé, VE2DBE, with a history going back to 1988. The desktop version is freeware for Windows (version 11.6.8 as of this writing, with the author's notes for running it under Wine on Linux and Mac). It extracts a path profile between two sites from digital elevation data, runs the Irregular Terrain Model, the model usually called Longley-Rice, over that profile, and paints coverage over a background map. Radio Mobile Online is a browser version by the same author, also free with a personal account, with a model he describes as a mix of ITM, a two-ray method and a land-cover loss estimate.
Its author states its purpose plainly: the program is dedicated to amateur radio and humanitarian use. Commercial use is not prohibited, but the author accepts no responsibility for it, and the user is responsible for honoring the terms of the external data the program loads. Radio Mobile Online goes a step further and is dedicated to the amateur community, with its frequency entry limited to the amateur bands. Radio Mobile is the work of Roger Coudé, VE2DBE, and this guide describes it from his published pages as of this writing.
Where it fits a two-way radio operation
For a first look at whether a repeater on a given hill reaches a given town, Radio Mobile is hard to argue with on price, and a good many techs first learned what a terrain profile looks like in it. A dealer with one engineering-minded tech who does not mind the setup can get useful plots out of it: pick elevation and land-cover sources from the author's list (USGS NED at 1/3 and 1 arc-second, SRTM at 3 arc-second, NLCD land cover for the United States), download the tiles to a local folder, enter the systems and units by hand, and run it.
The cost is time and expertise rather than money. The data is downloaded and managed by the user, the radio parameters are typed in, the result is an image, and everything that comes after the plot (who is licensed there, whether the study follows a public-safety acceptance method, what the customer receives) is a separate job in a separate tool. That gap is what this comparison is about.
Side by side
The Radio Mobile column states what its author publishes, as of this writing; where the online and desktop versions differ, both are given.
| Radio Mobile | Sentinel RF | |
|---|---|---|
| Cost model | Freeware, dedicated to amateur radio and humanitarian use; commercial use is not prohibited but is at the user's own responsibility. Radio Mobile Online is free with a personal account and limited to amateur bands. | Subscription per operation with seats included, from $99 a month for the full product. Every plan starts with a 14-day trial and no credit card. |
| Terrain data | Tiles the user downloads from sources the author lists: USGS NED at 1/3 and 1 arc-second, SRTM at 3 arc-second, and others worldwide. The online version runs on the author's server-side database. | USGS 3DEP at 1/3 arc-second, about 10 meters, loaded and cached by the service. Path profiles are sampled at about that spacing. |
| Propagation model | The Irregular Terrain Model (Longley-Rice). The online version mixes ITM with a two-ray method and a land-cover loss estimate. | Longley-Rice at the reliability you set, with terrain roughness measured around the site; Hata, COST-231 and Egli for quick estimates; land-cover clutter from ESA WorldCover, following ITU-R P.2108 and P.833 above 1 GHz. |
| FCC license and tower data | None built in. Sites, frequencies, powers and heights are entered by hand. | A full weekly copy of ULS and the antenna structure register. Enter a callsign and the site, frequency, antenna height and ERP load as filed. |
| TSB-88 tile study | Not offered as a named method. | A uniform tile grid with a Longley-Rice median per tile and area reliability against the channel performance criterion you enter, bounded to a service area you trace or upload. |
| Report output | Coverage pictures over the background map; the online version exports georeferenced PNG or JPG. | A letterheaded PDF for every study: parameters, results, the map, the method and the planning-study notices, kept in a report history. |
| License monitoring | None. | Renewal alerts at 180, 90 and 30 days, buildout deadlines, tower owner, status and height changes, FAA lighting NOTAMs, and area watches for new towers and licenses. |
| Who runs it | One person at a Windows PC with the data downloaded, or in a browser for Radio Mobile Online. | Every seat in the operation, in a browser, with saved studies and antenna patterns shared across the operation. |
What Radio Mobile does that Sentinel RF does not
- It is free. For a one-person operation, a volunteer group or a club repeater, that is the whole decision, and it should be.
- It runs offline. Once the terrain tiles are on the disk, the desktop program needs no connection, which still matters in a truck at a site with no signal.
- Its elevation sources reach worldwide: SRTM, Canadian CDED, and the author's list of regional sets for the far north and Antarctica. Sentinel RF's terrain is USGS 3DEP, so its studies cover the United States.
- It gives the user full control of the data under the study: which elevation and land-cover set, at what resolution, from which folder, and background maps of the user's own choosing, including scanned maps and satellite photos.
- It serves the amateur-radio uses it was written for, including the amateur bands above and below where land mobile lives, and 3D and stereoscopic views of the terrain.
What Sentinel RF adds
The FCC data sits under every study. A callsign loads the site as licensed instead of as remembered, incumbents for a short-spacing or Part 101 screen come from the same weekly copy, and a site intermod study builds its frequency list from the tower you click, FM and TV included.
The studies go past the coverage plot to the questions a customer actually asks. A receive-site survey solves every siren or outstation on its own terrain profile and sorts them weakest first. A TSB-88 tile study reports area reliability against the criterion you enter, bounded to the area you serve. A microwave path study works Vigants-Barnett multipath and ITU-R P.530 rain to an availability, with the rain zone resolved from the coordinates. A CBRS site study combines up to six sectors and derives the device category under Part 96.
The result is something you can hand over. Every study prints under your operation's letterhead, with the inputs and the method written out, and a saved study stores the inputs so that reopening it recomputes against today's FCC data and terrain rather than showing a number whose age nobody can tell.
And it is one seat for the rest of the work: the license and tower watch lists, the FAA lighting-outage alerts, the FCC search on a map, and the cited answers from your own manuals, for every person in the operation rather than the one who set up the data folder.
Both are planning tools. Neither is a measurement, no prediction replaces a drive test on a system that has to be accepted, and Sentinel RF is not an engineer of record: on a public-safety design its output informs licensed engineering review rather than standing in for it.
This guide summarizes the rules and methods as they stand; it is not legal advice or an engineering sign-off, and the rule text governs. Rule citations are to title 47 of the Code of Federal Regulations as published on eCFR.