Tx Upgrade and Spektrum Reliability

[Eifion Herbert]

So, follwing my recent purchase of a Hurricane I find myself now having run out of model memories on my DX6i, now my SO thinks this means it's time to get rid of some models, however a much more practical solution would be to upgrade my TX to one with more memories, and take advantage to some more advanced features, one thing I'd like would be the ability to do crow braking on sailplanes, and maybe telemetry too. The easiest thing would be to upgrade to a DX8, but I'm kinda starting to fall out of love whit Spektrum at the moment. I've just had another receiver go faulty, an AR600 this time, (it was a 6210 last time). It was in a Radian and just stopped responding for several seconds at a time, I managed to land safely, and have emailed Horizon regarding it.

Now I've got no doubt that Horizon Hoby will sort it out, they have a fantastic reputation for customer service, but I'm just starting to wonder. I've had two RX's fail, I've only got ten of the things - well nine really as one is the control board in a Blade Nano CPX - so that's a failure rate somewhere between a fifth and a quarter. Seems a little high to me, or have I just been unlucky?

The alternatives I've been looking at are the Hitec Aurora 9, and FrSky's new Taranis, however this would be considerably more expense and hassle as I'd have to switch the entire fleet's worth of receivers, and I'd need to keep the DX6i for the Nano CPX, (and the Blade 450 maybe, I'm not sure how the servo sync for the tail rotor servo will work with other brand's receivers) whereas if I were upgrading to the DX8 I could sell the DX6i and put the money towards it.

DX8 seems the way to but just loosing confidence in the Spektrum kit. That's twice I've had receivers fail in the air, twice I've been able to land, third time might not be so lucky.

[Alwyn Gee]

The fact that you say the receivers re-connected and you were able to regain control and land indicates to me that the receivers did not fail. It sounds more like and interuption in the signal which can be caused by other things non-spektrum orientated. Has the path diversity of your antenna been compromised when fiddling in the fuselage to couple up servos etc? How often do you do a rqnge check? How is the antenna on your trannie orientated as this can affect signal strength and path. and create blind spots if it gets end on the the model.

I've been using it for the last 5 years with none of the reported problems. I suspect that many of the so called problems are more likely pilot error but it's easier to blame the gear. You've more or less answered your own question so just bite the bullet and go for the DX8, you wont be disappointed.

Alwyn

[Chris Bott - Moderator]

Eifion I upgraded to a Dx8 and have never looked back, it's a great transmitter and moving up meant the programming was very intuitive for me.

I do worry that there are many stories about problems with Spektrum gear, but (touching lots of wood here) I haven't found any problems myself.
I sometimes get the impression that if a model develops a fault and it's on Spektrum gear, then spekky is blamed, but if the gear is from any other manufacturer then the real cause of the problem is looked into. In your case it does sound like they were Rx faults though.

I guess you "pays your money and makes your choice" as they say.
You could of course keep your first 10 models on the DX6i, and go for a different manufacturer for new models. Or even keep the Dx6i for "bind n flys" and some of your old models?

Oh, I'm finding the Dx8's glider programming very good indeed. What I do miss on it however are finger tip sliders for things like flaps etc. If you think you'd use these, another make may be better. (Or a Dx18!)

[Vecchio Austriaco]

I am completely behind Chris - Even I have changed recently (1 year ago...) to a JR I still have a very positive opinion about Spektrum. Real value for the money and in case of a problem good customer service. And this is not just in the UK - had an issue with my DX7 years ago in Italy, all done by horizon hobbies - at zero cost.

This brand brought a revolution of comfortable programming and reliability together with an affordable price into our hobby.

VA - paid by the cable industry - and not by Horizon....

[Eifion Herbert]

I'm fairly sure these were in fact receiver issues, the 6210 was confirmed faulty by Horizon's engineers when I sent it in. The 600 I haven't sent in yet, but is showing very short on a range check, and I've tried it both in and out of the model, with different known good servos and separate NiMH battery rather than the speed controller BEC, so I'm as sure as I can be that it's not the installation. I currently do a range check for a new installtion, or for any changes in the installation, so different RX battery, different servos, or moving a RX from one model to another I will do a range check, also if I've done any repairs on the model. Maybe I should get into the habit of doing a check at the start of each flying session.

I did have another AR600 fail on initial range check in a new model, as a result of me just plonking it in there any old how. Once I'd actually positioned the antennae properly at 90 degrees to each other it worked fine. I was thinking the issue with the AR600 in the radian might have been due to orientation to the TX antenna, it was pretty high up, and not very far away laterally, so maybe one 20 degrees or so away from being overhead. However I think my subsequent range checks both in and out of the model eliminates that.

I agree that Spektrum tends to be blamed very quickly for faults compared to other brands, and I'm trying not to fall into that trap, but trying to be rational and evidence based in my descisions. It's just that before putting so much money into my next radio you don't want any doubts in the back of your mind. It's nice to see the DX8 is well regarded though.

[Erfolg]

I have wondered for some time about Spektrum.

The sheer number of people who say the after sales service is wonderful, that is after some fault or a breakage has been encountered.

As far as I am aware i never read references to other 2.4 systems going back for service. To be honest I had thought for some time, if your RC gear goes down, there is no option but replace it, yet Spektrum seems different.

In one club i am a member, there does seem to be the odd issue, with Spektrum, but it seems more to do with batteries than the sets themselves.

[Lee Smalley]

I have had the odd problem generally with 600 based rxs my ar7000 have been faultless still there is no doubt in my mind there are far better protocols out there than dsm2 and being a confirmed jr fan I was going to switch to dmss but having just experienced macgregors horrific after sales service on my 11x zero I have cancelled that thought, almost bought a dmss module for it as well

[Trevor Crook]

I often wonder if the number of posts etc. about Spektrum problems is simply that it is by far the most widely used 2.4 radio make. I say I "wonder" because I doubt you can obtain figures, but in both clubs I am in, there is probably more Spektrum gear than all the other makes combined. Personally I've never had any control issues in 5-odd years of using the brand.

I'm a satisfied DX8 user now. Programming is pretty intuitive, but I think when I did the last software upgrade from 2.6 (I think) to 3.0, the sub-trim directions reversed, so they could do better.

The OP should go the route he is most comfortable with. All of the major brands work well, best to look at some other Tx's at his LHS and decide whether the expense of changing is worth it. Also consider that any make can go wrong, and then the quality of support really matters, so it's worth researching this, too.

[Eifion Herbert]

Had another "occurance" today with my DX6i that has made me question it. I have with me at the field my Radian, Alula and the Hurricane. After flying the gliders I have a flight on the Hurricane, and everything goes perfectly. While the Hurri's battery is charging I have another few flights on the gliders. Then I come for a second flight on the Hurri, and during pre-flight it becomes apparent that something has gone awry, as my ailerons and rudder have magically reversed direction, and my flap settings and my flap to flap mix have been reset to default. I quickly sort this out, and, possibly against best judgement, take off. In the air it becomes clear that the rates have also reset themselves as the normally well-behaved Hurricane was all over the place, I called landing, and just about managed to bring her round the circuit and safely, if not prettily, back to earth without damage.

Any idea how the settings in a model memory got wiped? I've got my own idea on how this might have happened, but don't want to post it yet so as not to bias anyone elses thoughts.

[Former Member]

[This posting has been removed]

[Kris R]

I've never had problems with recievers, (I have 12 different ones). However my DX6i has reversed the aileron servo twice in the last three years. (Why only the aileron servo?). Both modles had been flown many times on the same setting. The first time I put it down to my error as the plane had not been flown for a few weeks, the second time was the third flight of the day for my WOT4. Yes, you have probably guessed, I did not check the movement before take off. OOOps! Now have the DX8i as well, never had any problems with this excellent transmitter. I now check all movements of all surfaces before take off, which I should have done previously. When the servo reversed all the other setting remained the same? I'm still a Spektrum fan.

[Martin Harris - Moderator]

I suppose someone should ask if you had a mobile phone about your person - a question being asked quite frequently these days is whether the "old" advice against having them in close proximity has any validity...

[Trevor Crook]

Could it be a temperature related fault? I was flying this afternoon and it was very warm - tried to keep my tx in that shade between flights, although they should cope OK. Best get Horizon to look at it. Incidentally, there were at least 2 of us with dx8s, a dx7s, original dx7, and a dx6i. None of had the slightest problem.

[MikeS]

It does seem the DX6I has a problem with reversing it servos but more information is needed before it can be confirmed.

Not sure if having a mobile in your pocket could cause the suggested problem with the DX6I but something strange that happened to me and not just once while at the club. I switch on my DX8 then power on my AR7000 in the Pawnee and nothing happens on the rx. Ok turn everything off and try again. Hmmm so I try to 're-bind the system. The rx flashes as it should and binds.

Ok power on the radio then the rx and again nothing. A bit of head scratching and nothing comes to mind. My car is a Vauxhall Mervia and now and then If on my own at the club I leave the car radio on and yes this day I had. For some reason I turned off the car radio while trying figure out the problem.

And yes the rx locked on as soon as the car radio was turned off. Put the car radio back on and the rx still stayed connected. Powered of the DX8 and rx and back to the problem until the car radio was turned off.

When some fellow club mates arrived I showed them and we where all baffled by it. I know there is some scientific answer to this but if a car radio can do this then it would not surprise me if a mobile device of some kind might cause a problem with these radios yet I have not had a problem myself as far as I am aware.

Mike

Edited By MikeS on 22/07/2013 07:08:58

[Eifion Herbert]

The car radio? Was that reproducable? I am not an electronics engineer but I'd have thought that the car radio would do nothing but receive, not transmit.

In may case I did not have a phone on me on this occasion. I've had a phone on me in the past as if I am flying alone I consider that to be the lesser risk, and hasn't seemed to affect anything. Yesterday as there were other people flying my phone stayed in the car as per club rules.

I think the problem with my DX6i was that one of the batteries was loose. The TX beeped at me a few times while picking it up, handling it while getting the Hurricane ready. Gave the TX a little shake and I could hear one of the cells moving, and when I undid the battery cover sure enough it popped out. A little adjustment of the contacts sorted that out, but obviously the damage had been done. Usually when you switch off a DX6i it says "Saving Settings" on the screen. I'm wondering whether a couple of sudden power interuptions could have messed up the settings stored in the model memory. I've read of DX6i's doing this if you leave them switched on and the battery drains, so it's logical to think they could do it on a battery pull as well.

While discussing this a clubmate mentioned that having individual AA cells in a TX is against BMFA guidelines, for this very reason. If so there must be a hell of a lot of non-regulation DX6i's in use. A quick scan up and down the pits at my club on any given weekend shows that Spektrum is by far the most popular brand, of which the DX6i is a very popular model - or has everyone done a battery mod and voided their warranty?

[Peter Miller]

I bought a DX8 when they first came out. Never had a spot of trouble. A clubmate bought one just after that. Never had any trouble.

The only time we have seen a model crash was when the person concerned used an Rx without the satellite Rx. but then, he was an accident looking for somewhere to happen...and succeeding !

[Eifion Herbert]

Well I received a package in the post this morning from HH containing a brand new AR600. This is great customer service, especially considering I didn't have the purchase recepit, and mentioned in my covering letter that I understood if there was nothing they could do.

There was also a test report stating that the receiver I sent in tested OK, but they replaced it anyway. I'm a little puzzled by this, as it was consistently coming up very short doing range checks, but very happy with the service from Horizon Hobby.

[Former Member]

[This posting has been removed]

[Mal Quelch]

I was going to suggest a dirty on/off switch in the Tx during switch off, thus failing to save settings. Loose cell did just that it seems.

P.S. I never took to spektrum so am not a user.

[Dizz]

MikeS - Does your car radio have Blue Tooth? If it does it will be transmitting in the same ISM 2.4-2.4835GHz band as our radio control transmitters.

BTW, mobile telephones use 2, 3 or 4 of the 850,900, 1800 &1900 MHz frequency bands available depending on what country and what service you have.

Pete

Edited By Dizz on 22/07/2013 14:05:10

[Erfolg]

I would guess that our club is probably 50% Spektrum the majority of the rest being Futaba, but with Multiplex and some Czech manufacturer and the odd Chinese radio.

What surprises me, and unfortunately I am not totally clear what the circumstances are, Spektrum users rebind. It seems, although I could be wrong, if someone gets the sequence of switching on the Tx and Rx.

Yet, from what I have read on this site, this should be no different to a brown out as I think Tim calls them. Also in some testing, I seem to remember that a number of brown outs had been registered during a flight, with no apparent impact on control.

In my case, with Futaba, I test my failsafe by turning of the TX. I would have thought that this is no different to the brown outs that Spektrum records. In my case I never know if there has been an issue, as Futaba does not record this data.

All of which has puzzled me, as it seems to my mind that there is no difference to switching on the Rx first, surely it is another brown out, so rebinding should not be necessary, or is it somehow differ

[Pete B]

With the greatest respect, I think you might be getting a tad confused here, Erfolg.

'Brown-outs' and binding are entirely separate issues and have no connection whatsoever.

A 'brown-out' occurs when the Rx voltage drops below the limit at which it can continue operating - normally about 3.5V with Spekky gear.

Binding is a process where the Tx and Rx 'talk' to each other to ensure that they have matching GUID codes.

Switching on a Spekky Rx before the Tx results in the Rx not responding until the Tx transmits. Once the Tx is transmitting, and confirms the correct GUID, the Rx will activate, with a solid light on the Rx and continue to operate normally.

Switching the Tx on first has the same effect - when the Rx is switched on, the Rx looks for a transmission with the correct GUID and will not connect unless it does so.

I have always followed the accepted 'Best Practice', from MHz days, of switching on the Tx before the Rx, even though Spektrum advise that either way is acceptable - unwisely, IMHO. It's worked every time for me.

I too check my failsafe on the DX8 by switching off the Tx. The result is the Rx goes to failsafe. When the Tx is switched on again, it regains control in a few seconds. On DSM2, the Rx light will flash to indicate there has been a loss of signal at some stage.

Whilst the evidence is that it can apparently happen, I've never had an Rx unbind itself, either, in over 4 years of using Spekky. If you are seeing Spekky users having to re-bind models on a regular basis, something is very, very wrong....

When you mention that a number of 'brown-outs' have occurred in flight, I wonder if this is indicative of the fact that the builder has given little consideration to the need for a stable power supply and is perhaps using a BEC beyond its capabilities? Alternatively, if you mean there has been a loss of signal, is it because of a flawed radio installation and inadequate siting of the aerials?

Either way, both these situations can be traced back to user error, not a system failure. Given that a significant proportion of Spektrum users are novices, who may lack the experience and knowledge to build a safe, reliable, installation, that may go some way to explaining why Spektrum gear seems to have so many 'failures'.....

Be assured, if experience had shown me that my gear was anything less than reliable, it would have gone long ago, as I can't afford to throw models away......

Pete

[Former Member]

[This posting has been removed]

[Masher]

I totally agree with Pete B and have exactly the same reliable performance with DX8 and numerous model/receiver combinations

[Erfolg]

Pete

The brown outs I am referring to, I understood that Tim Macay had recorded on a flight. So it seems I have misunderstood what Tim did, and what a brown out is. I thought it was a loss of signal. Although I am sure Tim reported there was no apparent impact on the model. But my memory could be failing me.

I thought that a GUID was "Globally Unique Identifier". I would have thought that Spektrum Rx would go into failsafe if it did not see the TX, even on switch on.

With Futaba, it seems to follow the process of going into failsafe, although some Tier 2 Rx take about 5 seconds to do this, others are apparently instantaneous.

I to do not make a practise of switching on the Rx first, as at one time manufacturers suggested that it was non preferred process (I think it was in my Waltron bumf). I was told by a electronics guru, the issue was really poor discrimination of similar signals, which in close proximity could cause an issue, and the issues of discrimination increased with Tx separation. So I am not sure it still is an issue, though I still do not do it as a habit. Just the once as a failsafe check. The Rx went into failsafe, that is the motor did not start and the control surfaces just sat there with a twitch.

From what I have vaguely witnessed, is that under similar circumstances, from time to time they have or do rebind. As my interest is slight, and knowing little of Spekrtums, I am curios, that more issues seem prevalent with this aspect than Futaba (touch wood), so it appears. As a binding plug is asked for occasionally. But being honest, what ever the issue, it does not seem to affect safety/operation of the set up, I assume that the Rx does not operate.

I think I have seen at least one issue where the model parameters did not appear to be save , after adjustment. I put this sort of thing down to the variation that all manufactures seem to have in the menu structures, sequencing and more prevalent the actual psychical interfaces, ie buttons, rollers, touch panels and screens.

After all that, the actual radio link is mostly solid, although it was suggested that one model crashed due to using some camera system interfering with the Rx. Like many aspects with radios, there is little, if any evidence.