dx9 problems

[phil arena 1]

Hi has any one else had problems with the dx9 radio I have had 2 glitches and loss of control of 2 models one I recoved but my latest blaze model crashed due to loss of   . signal  battery charged  model range checked also  binded properly any   idears

Edited By phil arena 1 on 15/05/2016 21:36:39

[Dave Hopkin]

Lots of possible and well documented potential causes:

1) RX Battery overload dropping RX volts below threshold causing a brown out which will recover itself when volt drop is removed

2) Badly placed RX aerials

3) TX Antenna pointing straight at the model - but DX9 has two antenna I think so shouldn't be that

4) Using DMX in a busy RF environment

5) Cloned RX's

6) Low charged on Flight Battery

7) Vibration causing a poor socket connection to disconnect in flight

[Robert Putley 1]

What make and type of RX are you using Phil? Also what was the position of the aircraft?

[..]

Phil , this forum and many other RC flying related forums are full of debate surrounding the Spectrum signal loss / glitch problems so unfortunately you are not alone in having problems.

Most threads end in argument , so I won't add anymore here. Lots of info if you search tho.

[John F]

There is nothing as such to suggest a generic Spektrum problem and there is no way on earth that Spektrum would be allowed to keep selling their products if there were.  Some people have gone to great lengths and tested the equipment to destruction to try to prove whether there is an issue - to no avail. I can't find the link at the moment for one extensive write up I saw last year.

I believe that they are the victim of their own success in the same way as the Amazon Kindle.

The product is popular and therefore has sold x times as many more of that particular product as anyone else. Any complaints, case issues, signal losses, accidental crashes, whatever ends up on a forum. The chances of folk hearing about it are therefore multiplied as more and more folk buy that particular product but in reality the number of issues could still be only a microscopic number of total sales.

There are also almost as many Futaba, JR, DJI multirotor and Hitec radio signal loss glitches if you google them.

The fact that alongside random, and rare, actual faults there could be a multitude of other reasons such as incorrect installation of Rx, loose wiring, temporary shielded Rx due to poor siting of Rx, voltage issues with battery, a dead area in the location you fly etc. There is also the possibility that you just have a bad day, crash and then look towards blaming the radio?

At my club over the past year, from what I am aware of, we've had one Spektrum, a Multiplex, two Futaba, and a couple of other random branded crashes but the most popular brand radio for a crash is Taranis at the moment which have, according to the scorecard, had five crashes that are suspected radio issues.  They don't even equal the number of Spektrum radio users at the club yet beat them in the number of suspected radio issues!

Almost all of the folk who have got Taranis sets at our club used Spektrum before and converted en mass last year to Taranis with a nice discount as they bought eight sets in one go.

They converted because of the perceived fear of using Spektrum. Only one person had any issues as such with their radio, it is just that rumour got the better of them and they went for Taranis.  The price is also a major factor and probably the reason why Spektrum got so popular in the first place.

One of them is selling his Taranis gear and has gone back to Spektrum already!!

Edited By John F on 16/05/2016 08:48:23

[john stones 1 - Moderator]

Now you're adding to the problem by casting doubt about Taranis without proven facts John

John

[Tim Flyer]

I do not believe this problem is specific to one manufacturer.

One issue which I think should be addressed by all radio manufacturers is improving receiver to battery connections . I believe this needs to be done particularly as we are flying larger models on average these days. I think the simple "intererference" fit plug in battery connections to receivers is not good enough.

I would like to see a locking type plug plus more durable battery wires.Receivers seem to be designed to be super light rather than durable. I think many brown outs whether spectrum futaba or others are caused by loose or not properly inserted battery plugs. This can often occur when fitting wings on a plane when the wires are accidentally pulled. Vibration from an engine may then totally loosen the connection in flight. 

Edited By Timothy Harris 1 on 16/05/2016 11:32:41

[Don Fry]

All irreverent, Phil has posted he has nearly crashed two aircraft, no backup detail. Nothing to pontificate on, just presumptions, and assumptions.

I sometimes also wonder, if before you can slag off a manufacturer, let's have an idea of experience of successful flight.

For sense, read John F, above, but instead of reading it as criticism of Tarranis, read it as an assumption that some folk are never happy, fail to understand their kit, fail to test it, maintain it, and then wonder why they got unlucky.

[john stones 1 - Moderator]

Same thing Donald, unproven crashes attributed to a brand, rest i'll agree with may be umpteen causes. Never had a glitch I couldn't pin down, to ANY brand myself.

John

[Tim Flyer]

I see. Nothing wrong with suggesting manufacturers improve their receiver power connections I should also add switches to the list, along with the connectors. These are all the same I was using in the 1970s . Obviously this may well have no relevance(irreverence?) to the original post as forensic work would've required to ascertain the true cause of signal loss which could be one or a multitude of factors.

[MattyB]

Posted by Donald Fry on 16/05/2016 12:18:24:

...I sometimes also wonder, if before you can slag off a manufacturer, let's have an idea of experience of successful flight.

For sense, read John F, above, but instead of reading it as criticism of Tarranis, read it as an assumption that some folk are never happy, fail to understand their kit, fail to test it, maintain it, and then wonder why they got unlucky.

Repeated for truth. Isn't it strange how those who lose who consistently lose models to radio "failures" nearly always continue to have issues with their new brand of choice? As the IT industry would say, it's a PEBCAK error - the human is almost always the main source of the problem. I have also observed this group tend to exhibit a higher than average tendency to hit LVC and on their batteries and launch with their ailerons reversed too...

[MattyB]

Posted by Timothy Harris 1 on 16/05/2016 11:27:52:

I do not believe this problem is specific to one manufacturer.

One issue which I think should be addressed by all radio manufacturers is improving receiver to battery connections . I believe this needs to be done particularly as we are flying larger models on average these days. I think the simple "intererference" fit plug in battery connections to receivers is not good enough.

I would like to see a locking type plug plus more durable battery wires.Receivers seem to be designed to be super light rather than durable. I think many brown outs whether spectrum futaba or others are caused by loose or not properly inserted battery plugs. This can often occur when fitting wings on a plane when the wires are accidentally pulled. Vibration from an engine may then totally loosen the connection in flight.

Yep, have to agree with this - servo connectors have been essentially the same for decades, and are pretty suboptimal in big, expensive petrol models with current hungry servos and lots of vibration. I put a smear of contact adhesive between the plugs on my RX to improve things a bit, but a proper locking mechanism would be far better. I am amazed one of the big manufacturers has not thought of doing this as part of their premium ranges; surely there would be a profitable market out there for installing these in turbines and big scale models?

[Tim Flyer]

Cheers. Matt. I was just discussing it this weekend with fellow club mates. Many flyers now use petrol with its vibration increase plus bigger sometimes Life / Lipo batteries or 5cell Nimh and high power servos which are sometimes brushless. It seems strange that we have not increased the wire and plug quality as we are certainly drawing more current. It probably wasn't the right thread to put this on but I would like the manufacturers to consider this. Maybe they should make a 'heavy duty' version of each receiver with better lock on power supply . As you said earlier I can't see any less reliability between major manufacturers. What we have seen at my club is fake cheap gear bought on e-bay from the Far East compromising safety . I saw some awful fake futaba servos someone had fitted . They were dangerous!

[Don Fry]

Can't help having some agreement with better locking plugs, although only one failure in 50 years, a dry joint. Switches however I never seem to trust. Caught a fair few about to fail.

[MattyB]

These are handy for extension leads, though personally I've never had any issues with an appropriately sized piece of heat shrink over both sides of the connector. +1 on switches though, I hate the things with a passion!

Edited By MattyB on 16/05/2016 18:59:33

[Frank Skilbeck]

Posted by MattyB on 16/05/2016 13:49:43:

Posted by Timothy Harris 1 on 16/05/2016 11:27:52:

Yep, have to agree with this - servo connectors have been essentially the same for decades, and are pretty suboptimal in big, expensive petrol models with current hungry servos and lots of vibration. I put a smear of contact adhesive between the plugs on my RX to improve things a bit, but a proper locking mechanism would be far better. I am amazed one of the big manufacturers has not thought of doing this as part of their premium ranges; surely there would be a profitable market out there for installing these in turbines and big scale models?

Something like the locking bar on the Multiplex Pro Rxs maybe (which also have individual servo power overload, internal dual Rxs and take and standard plus MPX 6 pin plugs for power). But most premium models using Futaba, Spektrum, JR, Jeti etc would probably have a Powerbox system (or the new Frsky equivalent) so this isn't needed on the Rx, especially if using some form of S/X/Serial bus link.

[MattyB]

Posted by Frank Skilbeck on 16/05/2016 19:21:09:

Posted by MattyB on 16/05/2016 13:49:43:

Posted by Timothy Harris 1 on 16/05/2016 11:27:52:

Yep, have to agree with this - servo connectors have been essentially the same for decades, and are pretty suboptimal in big, expensive petrol models with current hungry servos and lots of vibration. I put a smear of contact adhesive between the plugs on my RX to improve things a bit, but a proper locking mechanism would be far better. I am amazed one of the big manufacturers has not thought of doing this as part of their premium ranges; surely there would be a profitable market out there for installing these in turbines and big scale models?

Something like the locking bar on the Multiplex Pro Rxs maybe (which also have individual servo power overload, internal dual Rxs and take and standard plus MPX 6 pin plugs for power). But most premium models using Futaba, Spektrum, JR, Jeti etc would probably have a Powerbox system (or the new Frsky equivalent) so this isn't needed on the Rx, especially if using some form of S/X/Serial bus link.

Yes, that locking bar is exactly the kind of thing I was thinking of, though given those RXs start at around £140 I'd also expect them to make my tea as well! And yes I know they are designed for expensive models where cost is not so much of an issue, but even the std Mpx RXs are expensive compared to the competition; I used to be an avid fan as did many of my soaring buddies, but the vast majority have gone FrSky or Jeti in the past few years.

Not sure I understand your point re: the Powerbox and SBUS bit though... Unless Powerboxes have a locking servo connectoraren't  they are just as likely to fail as a servo plug into an RX? In fact you could make a case it's worse because the total # of connectors are actually increased by one, and if the SBUS does work it's way out of the RX for any reason you lose all channels, not just one! (Assuming you are not running dual RXs of course)

Edited By MattyB on 16/05/2016 19:58:12

[phil arena 1]

Posted by phil arena 1 on 15/05/2016 21:34:34:

Hi has any one else had problems with the dx9 radio I have had 2 glitches and loss of control of 2 models one I recoved but my latest blaze model crashed due to loss of . signal battery charged model range checked also binded properly any idears hi I am using a spectrum ar500 rx mounted in the centre of the fuz behind battery. rx attached by Velcro small aerial inside model long aerial outside along the fuz

Edited By phil arena 1 on 15/05/2016 21:36:39

[Colin Carpenter]

Phil. Google shows your receiver to be DSM2 . Correct ? Only my experience here , but I have found that if DSM 2 loses signal , the reconnect time is too long to avoid hitting the ground. Whatever the reason for the loss ! A change to DSMX and no further losses of signal in over 1400 flights. I too have a DX9. Very happy with it ! Colin

[MattyB]

Aha - the infamous AR500. Not Spektrums greatest product ever. I would ditch it for something (pretty much anything!) else if I were you.

A useful thread from this forum describing a test procedure to see if your RX may have an issue or not.

Edited By MattyB on 16/05/2016 21:36:55

[ben goodfellow 1]

boom!!!!!...it has to be dumb thumb ,bad set up low battery , it wont ..be the dsm death reported a thousand million times .nothing ever goes wrong with spektrum, LOL...i watched a dx9 put one in the other weekend spectacular owner was told 6 (six ) weeks to fix it ,, he now flys multiplex

[Robert Putley 1]

Purchased a DX9 as soon as they came on the mkt. Fly DSM2 and DSMX. Never had a problem after much use. A really super transmitter. Am very happy with it .

Have recently bought a DX9 too.

[ben goodfellow 1]

i wouldnt feel left out .it wont be long!!

Edited By ben goodfellow 1 on 16/05/2016 21:49:26

[Pete B]

Posted by ben goodfellow 1 on 16/05/2016 21:48:49:

i wouldnt feel left out .it wont be long!!

Seven years plus and I'm still waiting.....

Pete

[MattyB]

Posted by ben goodfellow 1 on 16/05/2016 21:41:40:

boom!!!!!...it has to be dumb thumb ,bad set up low battery , it wont ..be the dsm death reported a thousand million times .nothing ever goes wrong with spektrum, LOL...i watched a dx9 put one in the other weekend spectacular owner was told 6 (six ) weeks to fix it ,, he now flys multiplex

When you can back these statements up with facts and data that show Spektrum to be inferior from an RF resiliency perspective we will all believe you. Until then, it is just wild and unsubstantiated speculation. Yes Spek does have a reputation for RF failures in some quarters, but that can be explained by a number of factors based on (now distant) history and probability:

• Early Spek sets DID have some issues - high brownout voltages, slow reboot times and DSM/DSM2 were not FHSS implementations, making them more vulnerable to narrowband interference than current FHSS and DSSS/FHSS hybrids. Every one of these issues has been addressed by the DSMX receivers and TXs released over the last 5 years. Some people have long memories though, so whenever they see or experience a loss of Spek equipped model the RC is automatically blamed.
• Spek were the first to utilise 2.4 in a widely available RC system, so at the start they had to teach everyone the painful lessons associated with power supply and aerial orientation in digital 2.4GHz systems. Whoever would have been first would have had to do this, and would have been tarred with the same brush as a result (just ask XPS; their Graupner branded offering in the EU had to be withdrawn from sale after the parent Graupner refused to supply sets with anything other than a 4.8V NiCad pack causing a raft of failures as a result).
• Spek are both the most successful brand in terms of sales and the beginner brand of choice. That mens in pure numbers terms there will be more Spek crashes than any other brand; more sets out there = more chance of an issue, and beginners make more mistakes of all kinds than experienced hands. A great example of why correlation does not necessarily imply causation (this is a good one too... ).

PS - No, I am no Spek fanboy; I don't own a single piece of Spektrum kit. However I would happily use DSMX because the fundamentals of their implementation are as good as everyone else, and because I have understood the technology and have read the instructions on how to install and power 2.4 setups correctly. I also have many, many friends who fly Spek with zero issues. Let's face it, underneath the covers all of these 2.4 implementations are now very similar; many use the same chipsets, all use FHSS, and just a few (DSMX, Jeti Duplex, JR DMSS) add in DSSS to make a theoretically more resilient hybrid solution. Ultimately though any modern FHSS based system is incredibly reliable from an RF perspective; the issues tend to be courtesy of the pink squishy thing doing the radio install and holding the sticks...

Edited By MattyB on 17/05/2016 00:50:28