We have had lots of Club chatter over the months/years about radio range, losing signal to the boat and so on… the merits of different transmitter brands etc. Remember, you can lose radio contact with the boat for SO many reasons.

You’ll all know that Flyers in free sky find they get simply massive radio range and quote exciting numbers stated in whole kilometres – 10 km not being unusual.

What range do we need in radio sailing? 100m maximum I should think. Nonetheless, “who gives the strongest signal and furthest range” continues to intrigue us.

We have had Club members trialling ceramic antenna based receivers (no dangly wires) from Spektrum and Radiomaster ELRS. These dinky little receivers are great in a sailboat “pot” with zero wires from a space management viewpoint. They were though designed/optimised for indoor car racing – all very different. The Futaba equivalent wire-free receiver actually states a maximum 70m range, so I’ve not bothered to test it.

A unique combination of circumstances came up this morning. Two identical, carbon fibre hulled F6 Marbleheads, one with Radiomaster TX15 and ELRS (ER3Creceiver). The other rigged with Futaba T10J and their cable antenna F3006SB receiver…. fitted in a SailsEtc antenna frame that tucks it neatly at the pot top,… wires at 90 degrees as recommended by Futaba. …Plus no rain!! …Plus a spouse who was willing to help by watching boats out of the kitchen window (very rare treat!). All batteries were fully and equally charged. Transmitter power/strength settings, transmission packet rate, were as they were to-of-the-box and new.

We sail on dead flat reservoir water, so with a solid surface beneath us, not free sky. Clear line of sight to the boats, no obstructions. Today’s tests, Positions 0-5, were similar really – carried out on a dead flat street, 200metres long, with line of sight to the boats. Then the next two measurement points I had to turn 90 degrees at the the road junction and walk along that street (measurement points 6 and 7). Measurement points 6 and 7 therefore lost line of sight, and gained a couple of houses in the way of the signal…. they were quickly more challenging to the radio, but I wanted to see which brand gave up first, and was it actually a “close thing”?? Measurements stated for position 6 and 7 were direct back to position 0, as the bird flies.

Measurements were taken via What3Words and a website named grid reference finder.

Conclusions

1. Nearly exactly the same range for Radiomaster ELRS and Futaba, around 200m. Easily enough for radio sailors and probably double what we might usually need.
2. Radiomaster lasted maybe 10% further (20m) than the Futaba.
3. Both lost signal by 240m. (Needs to be tested in a straight line at the reservoir.)
4. Despite being an indoor wire-free receiver, the RM ERC3i unit performed very well against the Futaba.
5. If I had patience I would test the Futaba again without the antenna frame. It would be interesting to see if dangling free wires into the pot (carbon fibre hull remember) makes any real impact on range.
6. Telemetry range was disappointing in both cases. Radiomaster gave up at around 50-60metres. Futaba lost telemetry signals at around 30metres. I believe the flying community call it “Fly By Telemetry”.
7. Good job we radio sailors are not interested in ranges of 10km away. No chance….