Hi ianed57 and Shipmates,
Reading through the post I think it could simply be poor main batteries, If his battery pack is not in good condition or or has poor connections under load the supply voltage will drop the ESC's BEC will not be able to maintain a voltage to the receiver the Mtroniks ESC needs a minimum of 6v to operate correctly (BEC).

On your first post you mention AA batteries, I assume they were his main power supply, if he only has 4 in series his max voltage will be 6v, and could easily dip under that, under load, causing problems to the receiver supply from the ESC.
Regards
Roy

Another suggestion and please don't take it the wrong way. Try earthing the motor case to the brass propshaft.

Hi Ian.
This is a strange one and causes a little scratching of the old grey matter.
Importantly,it’s annoying for your friend and no doubt yourself.
I don’t thing anyone is being abrasive in the true sense.
We all express ourselves differently and sometimes like text messages on phones things can be taken out of context.
Is he sailing on the Exeter flood relief system or salt water.
Look at the possibility of a dry joint as I suggested before,and Yes the motors should be suppressed.
Good luck.
Regards Bill

Hi ianed57.

It is a shame that your friend is not a member on this site as he would be able to test and answer all the suggestions and questions that have been put forward.

I don't think anyone is intentionally being abrasive i just think they are just getting there point across.

It is very good of you to try and help your friend with his problem, and hope he manages to find the solution.

Although it would be interesting to know how this problem gets solved.

Please keep us informed.

Martin555.

IanH,

You're bit late as all this has been discussed ad nauseum.

It's not my boat, I always suppress my own motors and I can't be certain my friend hasn't suppressed his, but I expect he has done knowing him.

And I can't quite see the need to be so abrasive.🤔

Ian

Looks like a motor needs to be suppressed.

Graupner motor aren't supplied suppressed😊😊

You should always suppress a motor even if you are running 2.4Ghz Consider the other people!
2.4Ghz maybe considered an " I'm alright Jack" but consider other modelers and never get a 2.4 Ghz below the waterline

Hi ToraDog,

Yes, when we were sailing together on Monday he range tested by walking about 100 ft away and all was well. It was only in the water that things went south.

When I passed on ideas from this forum to him I suggested that changing the motor might be a quick and relatively cheap way to either pinpoint it as the trouble or eliminate it but he seems keen to just change the radio over- and I don't blame him really.

I didn't really clock the type of universal joint he was using but I expect it was one of the red Huco types. I very much doubt if it was an all metal job.

Ian

Ian,
Just for giggles, has your friend range tested his boat, out of water? It would be interesting to see if the issue arises, especially if the motor in the model is not run. It is very easy to get sent in the wrong direction at times and going back to basics can be a mind saver.
Here is another thought from my archives, what kind of u-joint does the boat run? Metal, plastic, combination? If it is an all metal u-joint, similar to the old Octura units, they have been shown to create EMI, hence the plastic(Delrin) units with metal spiders. Just a thought.

Hi ToraDog,

Funnily enough we had this conversation a few months ago regarding one of my own boats. The motor in my friends boat was a Graupner and my understanding is that they have internal suppression, but I may be wrong.

Some years ago I had to resort to wrapping one motor in tinfoil despite suppression and that was using 2.4. I have since gone over to low noise motors which are an all round improvement.

As I said to Tony, the owner of the boat is now going to try a different radio so we'll see where that goes. I expect to sail with him again next week, making the most of the autumn, so I will report any developments.

Ian

Back in the day, for some of us that means today, EMI was a factor that was dealt with regularly y fitting capacitors to any motor leads. One of the wonders of 2.4 ghz radios is their resistance to EMI. That said, it can still happen, but usually it is there or not. Even if you run a 2.4 ghz radio in your own boat without fitting capacitors, that does not mean that your own boat won't interfere with someone else's if it comes close by your own.
All that said, an easy way to bench test a motor for EMI under load is to simply put the load onn the shaft with your fingers. It should be sufficient to simulate the water load and reveal EMI, if it is there. If not, look for the obvious, start at the battery, be it a pack or BEC.

Thanks Tony,
Very interesting as we wondered if it was the loading of the motor that may be causing it.
I contacted the owner of the boat yesterday with the ideas that have been put forward and he tells me he is going to change the radio. We'll see if that does the trick.

All the best Tony,

Ian

Ian, I have heard of a similar problem which one of our club members once suffered. When the motor was running off load all was ok, however when the motor had was under-load and in the middle of the lake it produced interference to the radio.
The club member's model it occurred with was a three motor Titanic and it was just one of the three motors which caused the interference. It took some finding as it only happened when the motor was at at a certain operating temperature. It was only solved with the help of an electronics technician who put monitoring equipment in the model.
What's different is that your friends model is on 2.4ghz, when it happened at our club it was in the days of 27mhz and things have moved on.

Thanks Pete and ToraDog,

I will pass on these ideas - it really is someone else's boat! I'm not sure if the owner was using bec or not. We hadn't thought about the antenna on the tx but that seem to equate closest to what was experienced on Monday so worth checking.

Pete, I have always found the old Planet to be ultra reliable and the tx batteries (dry AA cells) seem to last for years, but I have several boats on Spektrum using a fairly ancient DX5e and these always seem reluctant to bind, to the point where I sometimes wonder if it will. I replaced the tx batteries on Monday, (although the lights still went up to green) - better but still not great. Once it's bound on, no problems. I remember reading that the tx shouldn't be too close when binding but don't know whether this is true. Still think 2.4 is magic though!

Thanks for the various inputs.

Ian

Pete's reply is a very valid point. make sure that your receiver pack, if you are using one, voltage is up to snuff.
As for extending 2.4 ghz antennas; if the manufacturer makes longer replacement ones then you can try that. (I know that FrSky makes some for some of their receivers, I bought several). I would be hesitant to modify a factory antenna unless a very reputable source said it is OK to do so.
Here is another suggestion. I saw this recently where a gent put his boat in the water and it would not command, but on shore it did. his x-mitter used a screw in antenna and the lead inside the case was loose. Tightened it and all was cheery. Likewise if the antenna is not screwed all the way down onto it's mount screw. i had that happen to me on my F-14 radio. I hope this helps.

Hello Ian, Regarding the Planet problem, I have two sets of the old Planet 2.4 ghz, along with three Spektrum sets, the only problem I have noticed with the Planet gear, is that I get servo jitter when the battery is below 5.3 on the meter, this maybe the fault on the new sets too, but it's always worth checking that the battery voltage is well up😊

Cheers, Pete

btw, Have never had any problems with any of my Spektrum sets.

Thanks for that ToraDog- all adds to the body of knowledge. From memory, the rx was well up in the boat but the possibility of extending the aerial was discussed as people seemed to think 2.4 aerials weren't tuned to length.

I remember that with 27meg you had quite a lot of leeway with aerial length and I was told early in my life that you could run a boat with the aerial coiled up in the bottom, which surprised me, but which turned out to be correct, as I often did it.

What do we think about extending the aerial?

I will pass on all these ideas and see if anything works.

Ian

PS, having only recently gone over to 2.4 ghz, my learning curve has been steep. That said I recently asked a FrSky rep about the recommendation to mount the receiver antennas at 90 degrees to each other. The response was that in a boat it does not matter and is not required. The 90 degree mounting is more for aircraft because of the multi-dimensional
attitudes that they fly. I have mounted my antennas vertically well above the waterline and achieved full control and very good extended ranges.

Ian,
2.4 ghz receivers are very sensitive to signal blockage,, unlike the older 75 mhz systems. You indicate that the receiver antenna is routed away from other signal noise generators, but what is most important is to get the antenna above the waterline of the model. 2.4ghz will not penetrate water, to any great degree, so the antenna needs to be as high as possible.

Oh, by the way Bill, I also have several boats with old Planet radio and Mtroniks and they are always ultra-reliable so I shouldn't panic. This is new Planet gear. (And I'm not suggesting that is unreliable).

I got quite excited when I saw Planet was on the market again but it is incompatible with the old - of course!! Old Planet receivers are going for silly money now.

Ian

Hi Bill and Stephen,

Thanks for your input. I noticed that the motor was a smallish Graupner, probably a 400 size and brushed. The owner of the boat is a very neat and careful builder - I wish I'd thought to take a photo of the inside of the boat as the problem is unlikely to be because of sloppy building. It is interesting that he also wondered if loading the motor in the water made the difference, as it was basically the only change, but what to do about it? Might be worth trying a replacement motor. My understanding was that 2.4 isn't susceptible to motor interference.

In the end we could only suggest getting back in touch with the supplier of the radio - it was only bought in April - and see what they thought. I will let you know what transpires in the interest of closure!

Ian

Hi Ian,
Interesting problem.
It would be interesting to know if the motor is brushed, if it is brushed the problem may not show up until it is under load. Just a thought.
Cheers,
Stephen.

Hi Ian.
Very strange.
I have amongst others a Planet 2.4 with Mtronics gear.
I have never experienced this problem which is worrisome.
I always place my antenna horizontally as far away from the source of any electronic interference as possible.
It may be worth checking that there are no dry joints within your friends system.
Regards Bill

Thanks Rob and Martin,

As I say it isn't my boat so can't check the antennae but will pass on that info. I know that's how it is supposed to be but have always found 2.4 pretty forgiving regarding antenna placement.

It may be a case of back to the supplier and start again with different stuff. None of us have experienced this. Usually it either works or it doesn't. Ho hum!

Ian

Hi Ian,
i know very little when it comes to this sort of thing but i was wondering was the antenna on the boat horizontal or vertical and if that would make any difference.

Martin555.

Hi Ian.
Are the antennas above the waterline and set 90 degrees from each other?
Those are the only things that immediately come to mind that could cause a problem 🤔
Rob.