Glitches when using 35Mhz with electric

[Bob Moore]

Hi all,

A while back I converted my Wot 4 to electric and I'm still using 35Mhz. reluctant to change to 2.4 because I have a few models and the cost involved. When flying I get occasional rudder and aileron twitches. Last week I tried a diferent rx in the model and it was even worse.

What I'm wondering is are glitches due to interference through the 5v rx supply from the ESC (I do have one little ferrite ring in that line) or is it the proximity of the motor or esc to the rx? I'm just wondering if it's worth relocating the rx further to the rear in the fusi? And adding another ferrite ring thingy.

I've got two other leccy models, an Orion Westwings glider, and a lttle Depron Edge and don't get glitches with those, but they are much smaller motor esc set ups compared to the Wot 4.

Any suggestions welcome please. .I don't really want to buy another tx and rx just for this model. Too much hassle and expense.

[Ultymate]

Glitches are par for the course with electric models on 35Mhz Bob, will your trannie take a module if so you could get away with just 1 R/X and a module.

[Chris Bott - Moderator]

Bob I used to fly electric on 35Mhz a lot.

Yes definately separate Rx and aerial as far away as you possibly can from the motor, ESC and the battery wires. All of which can radiate interference that can get into a 35Mhz system.

I found that there was no single cure that would work on every model.
Once wrapping the Rx in foil helped a lot, but that didn't work on many others.

Different Receivers were more or less prone too.
Multiplex IPD being the best I found.
Corona receivers were surprisingly good, especially the ones that used crystals.

However after writing off a couple of models in close succession my flying confidence really took a knock. I changed to 2.4Ghz and have never looked back.

[Bob Moore]

Thanks for the replies guys.

@Ultymate, I have a Hitec Optic 6 Sport which unfortunately won't take a module.

@Chris , Think I will have a go and moving the rx further away and the foil idea too. The glitches with the previous rx weren't that bad, but testing the other one yesterday I had a couple of serious glitches. Fortunately they don't happen when close to landing, as I assume the tx signal is strong enough to overcome any interference.

I'm assuming that a rx being closer to servos shouldn't cause glitches?

Edited By Bob Moore on 09/09/2012 12:40:09

[Colin Naylar]

This is certainly a known problem and has been discussed several times. I solved it with ferrite rings on the ESC cable to the Rx - available from GiantShark - certainly cured my glitching (and the aeroplanes)

[Bob Moore]

Thanks for that. I have one ring in the feed to the rx, but the space is too tight for another. What I have in mind is to use a small extension lead to put the rx further away and it will also allow me to fit another ferrite ring or two.

[Myron Beaumont]

Bob

You can get a 2.4 Ghz module for your Optic6 ! I have a Corona set up on mine .I think I got it from GC (GS).Cheap as well

Cheers Myron

[Bob Moore]

I'm almost 100% sure that it's not possible with the Sport model. (Or not that easy.) I enquired from my dealer when I bought it. And this was confirmed when I Googled it.

There is a hack module available from HK but I don't think I want to go down that road really.

[Myron Beaumont]

Sorry Bob

Didn't realise the "Sport" was different from the straight Optic 6 of mine

[Andy Gates]

Bob

Like many others here I used to fly electric only on 35MHz, I was using an Optic 6 (non sport model).

I still fly a lot of my larger models on 35MHz and have never suffered glitches on the larger stuff, I only got glitches on the smaller stuff with smaller recievers and closer proximity to the ESC / battery / motors.

There is a proviso to this story though, the larger stuff I fly on 3S only and with DUAL CONVERSION recievers. The latter for me seemed to be the key to sucess, and right now with lots of people making the move to 2.4GHz these recievers come quite cheap.

Futaba ones work pretty well but best results seem to be with the Hitec ones, but please make sure you use the manufacturers dual conversion crystals with the DC recievers.

[Keith Berriman]

Bob is space tight I have seen models use a separate reciever pack and I think they isolate the red or live wire from the ESC to Rx

[Bob Moore]

Useful advice thanks.

I've actually got a spare dual conversion rx kicking about but couldn't fit it when I tried because of space, with an extension lead to the power input it should go in. (It has the appropriate crystal in. ) With luck that will improve things.The Wot is on 4s but I can't see that making a difference really.

[Richard Mumford]

Bob

For £26.31 + shipping you can buy a basic full range 4 channel Tx with 7 channel Rx included from here (the supplier formerly known as GC).

I've been using one for over a year on small fast flying wings, and it hasn't missed a beat. My original Futaba skysport 35Mhz set glitched on elevons and throttle all the time.

Edited By Richard Mumford on 09/09/2012 19:08:20

Edited By Richard Mumford on 09/09/2012 19:09:05

[Bob Moore]

Thanks for that, certainly worth a thought. I'll try my dual conversion rx and other solutions first though.

[NigelH]

Posted by Bob Moore on 09/09/2012 13:41:07:

I'm almost 100% sure that it's not possible with the Sport model. (Or not that easy.) I enquired from my dealer when I bought it. And this was confirmed when I Googled it.

There is a hack module available from HK but I don't think I want to go down that road really.

I've no experience of it but every review has five stars. May be worth looking at in more detail.

[John Muir]

I used to have a Futaba single conversion receiver in my electric glider and got glitches especially when the transmitter aerial pointed straight at the model. I changed the receiver for a Corona single conversion DSP receiver and suddenly, no more glitches. These are still available from Giant Shark for a little over £6 each, plus a crystal, although the available channels are pretty limited now I think. I also fly a Formosa on 35MHz using a Fusion receiver and that has no issues at all, but that's more expensive, bigger and heavier than the Corona. Both have some sort of clever digital signal filtering though, which I think might be the key.

[Former Member]

[This posting has been removed]

[Bob Moore]

@John, I found keeping the tx antenna very vertical improved things too. The Corona does sound interesting, I'll look into that too.  Out of stock at GC at the moment. Correction, they are in stock. Any idea what crystal will work with them. Just a usual Hitec single conversion one?

edit again! I see they take mini crystals but they don't have 70 in stock. Is there any reason why a normal crystal (with legs bent if necessary) wouldn't work, or do these have fatter pins. It looks a bit like that on the GC illustrations?

@Tom. Banning 35 mhz, and about time too? And why's that then? Most people at my club use 35 Mhz without any problems (as have I for ten years) and many can't afford to bin their gear and shell out for a new tx and a pile of rx's.

 

 

Edited By Bob Moore on 09/09/2012 21:25:29

Edited By Bob Moore on 09/09/2012 21:30:01

Edited By Bob Moore on 09/09/2012 21:57:31

[Former Member]

[This posting has been removed]

[PatMc]

I've flown electric models for about 16 years using 27MHz AM & 35MHz single convert & dual convert Rxs. At the moment I have half a dozen electric models still on 35 MHz with a mixture of makes (including a Micron home constructed one) both single & dual Rxs. I've never encountered any interference problems in any electric powered models. However I recently had glitching problems with a slope soarer that persisted even with a change of 35MHz Rxs but was cured with a change to 2.4GHz.

One of the 35MHz Rxs is now in an electric model the other is in a glider. I'm pretty certain that the interference that caused the glitching was from at least 2 of the servos - 4 HS82's

[Bob Moore]

No probs Tom. My glitches have only occured when the model is in air and some distance away I'm pleased to say. I can see that a rogue model on the ground could be a problem. One of our guys (on 2.4ghz) had his model run into his leg causing several stitches when I think he accidentally switched off the tx prematurely and hadn't set up his failsafe properly. The motor went full speed and ran into him. I don't have the whole story though. The first thing I do when I retrieve my Wot is pull out my battery link that I've fitted in the side of the fusi.

Interesting Pat. I had wondered if servos might cause interference.

Edited By Bob Moore on 09/09/2012 22:06:01

[PatMc]

Bob, it's the first time I've ever had glitching caused by servos - in fact it's the first time I've ever had glitching caused by anything other than someone switching on using the same frequency as me.

[fly boy3]

Hi Bob, I am new to elecrics, and have built 3 of Tom Wright's models. 2PLaggers, and his twin boom. I fly on an old Futaba, using 35Mhz. I use a synthasized Corona Rx, and (touch wood) never had a glitch in over 18months. My Rx is as far away as possible from the ESC. PS these model fly very well indeed. Cheers

[Bob Moore]

Thanks. I'm just this minute fiddling about fitting an old Hitec Dual conversion receiver in the Wot to try that out. A little bit futher away from the esc and slightly better aerial run. If that doesn't work I think I'll try a Corona. The spec and reviews on them are very good.

[Bob Moore]

I am very tempted by the corona , and would order one now but for the fact they don't have the mini crystals in ch 70 in stock. Can anyone tell me please if a normal crystal would be ok?