Tag Archives: ELRS

How Much Radio Range Do We Need Anyway??

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How far away can we see race marks, start line situations and sail numbers? Not far.

I’ve just had a bit of a shock though. You may remember that I have a horizontal, dead straight, line-of-sight, transmitter range test based in the street where I live.

I recently put Radiomaster and Futaba through the exact same test and basically got a radio range of around 200 metres for both of them. Blimey.

Radiomaster just a tad more maybe, but I ran out of straight street and had to go round the corner. That is way more than we need in radio sailing.. I can hardly walk THAT far.

You can read my recent range comparison for Radiomaster and Futaba here:-

Receiver Range Test Comparison – Radiomaster ELRS versus Futaba with Antenna Frame (from SailsEtc)

Tests conducted by RC Flyers in the USA suggested that Spektrum only reached maybe a quarter to half the distance of Radiomaster/ELRS. I was curious to test my DX8e against it. I am just starting to prepare the Datchet Radio Sailors’ online manual for Spektrum. I thought I’d put my own lovely Spektrum DX8/AR620 through the same range test, using the same boat…. before I start the programming and manual writing.

(©Datchet Radio Sailing)

I’m a bit stunned. At first, I thought it must be low battery power, and so changed all the batteries for fresh ones. Same result. So my next thought,… after swearing,… was “faulty transmitter”…. (you might say!!) …. but I’ve had this particular DX8 range tested and a fix applied at the Spektrum UK distributor, and it passed their tests just fine after that.

You might be thinking that it was caused by the smart but tiny, and wire free, ceramic antenna of the AR620 receiver. Maybe. Lovely kit though.

But the Radiomaster in this test also used a ceramic antenna in its ERC3i – even more weeny and more tiny that is. It’s so small, you’d be inclined to try and wipe it off the hull in case it’s a speck of mud.

The AR620 is about twice the physical size of the ER3Ci. When I get the time, I’ll re-test the Futabas without the SailsEtc antenna frame … just dangling wires in the pot … to be disproved, but I personally suspect the antenna frame (called “aerial holder” at SailsEtc’s website) is a big factor in this test.

I’m reluctant to trot down to TJD Models and buy a wire-antenna Spektrum receiver, as I’ve seen an official Spektrum video claiming that the ceramic antenna has better range.

But – well, how much do we need in radio sailing? I’d personally have difficulty racing 75 metres away – it’s surprising how far that is. I know a number of radio sailors who simply adore their Spektrums… but for myself, I’m still surprised by this test result. The guys at Datchet want me to test a FlySky over the same street. I’ll do that as soon as it’s practical – I no longer have a FlySky here, but I know where to get a loaner.

The article showing the results of the USA flyers can be found here:-

ELRS … So The Commodore Was Correct ….!!

ELRS … So The Commodore Was Correct ….!!

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Our Commodore, Phil H, has long been very keen on the performance of his Radiomaster-ELRS receiver… “never dropped a signal”, he says.

Can you read that table above ? – it’s a tad blurry, but I think you can. These are ground-to- ground test results of some major transmitter-receiver brands aimed at the Radio Flying community, …who are interested in distances measured in kilometres..

The test might also typically be using receivers with a lot more channels than we use in sailing. The test person gets more into the transmitters, but receiver capability will be a big part of the equation.

You have to keep a sense of proportion – flyers seem to worry about ranges measured in kilometres, whereas, honestly, if our boats are 100m away I panic about whether I’ll hit a mark…. or not be able to tell which one of the pack is “me” !!

No need for us to be extremely picky about range and distance, but it’s all relative….

Sure enough, Phil – the major conclusion of the test is that ELRS is basically in a class of its own. FrSky Tandem was quite close (see our recent website article), but we don’t see many of those. You can see why the tests were controversial, but essentially they left the receivers in one spot then drove the transmitters into the distance (flattish undulating terrain) until they dropped signal. I think at one point they drive over a hill and see if the signal is regained the other side.

When you are dealing with radio sailing distances of 100 metres or so, if you have signal drops you probably need to check out other parts of the system. … Interesting though…. The full link of this 2024 video is given below – it’s long and much of it somewhat heavy going. If you skip forward to around the 1’17”, the summary and results start around there.

https://www.youtube.com/watch?v=LargnWPSX04