Unreliable Spektrum AR6115e DX5e combo

[HobbyJumper]

The AR6115e receiver in my eflite Jn4 just doesn't want to connect to my dx5e reliably. Turn on transmitter; plug in battery; sometimes it works great; sometimes it doesn't at all; sometimes it takes a long time. Today the connection was instant, but then was lost while flying! That was new. Lucky I didn't wreck my plane.

I'm a totally rookie when it comes to this new R/C stuff, and would appreciate any tips toward diagnosing and solving problems like this.

The equipment is all new and/or in good shape. Batteries good too. No problem connecting the tx to any of my UMs.

Thanks...

[simibill]

The AR6115/AR6115e features DSM® technology and is compatible with all SpektrumTM and JR® aircraft transmitters that support DSM2 and DSMX technology, like the DX8, DX7, DX6i, DX5e, 12X, 11X, X9503, X9303 and Module Systems.

[xmech2k]

Spektrum website says on the Dx5e page:

Product Specifications

# of Channels: 5Modulation: DSM2Band: 2.4GHzServos: N/AReceiver: AR500 5-Channel Full Range Sport ReceiverProgramming Features: Servo Reverse; Delta Wing; HI/LO ratesModel Memory: 1Modes: Mode 2Transmitter (Tx) Battery Type: 4 AA Alkaline Batteries (included)Experience Level: BeginnerKey Features

• <LI style="BACKGROUND-IMAGE: none" nodeIndex="1">Basic 5-channel 2.4GHz DSM2 radio and receiver <LI style="BACKGROUND-IMAGE: none" nodeIndex="2">Easy-to-use control for basic models <LI style="BACKGROUND-IMAGE: none" nodeIndex="3">Includes AR500 5-channel full range sport receiver <LI style="BACKGROUND-IMAGE: none" nodeIndex="4">Delta wing mixing <LI style="BACKGROUND-IMAGE: none" nodeIndex="5">HI/LO rates <LI style="BACKGROUND-IMAGE: none" nodeIndex="6">Servo reversing
• JR and Spektrum compatible trainer system

So it's supposed to be DSM2. Maybe a bad rcvr or xmtter. You have the antennae pointed straight up? Not straight out from the xmttr but straight up? I've only used my 5e on the Apprentice it came with. Then I got the 6i and haven't used the 5e since, so other than that, sorry I can't help more.

Maybe if you have a buddy at the field with Spektrum stuff, you could try binding different things to sort try to confirm if it's a faulty rcvr or xmttr. Also, I've never thought of trying a 6 channel rcvr with a 5ch xmttr. Don't know if there may be any issues there.

Good luck, and let us know what you find.

[kenchiroalpha]

Hi
That RX is not compatable with the DX5 or DX6
http://www.spektrumrc.com/Products/D...dID=SPMAR6115E
Take care
Yours Hank

[Turner]

Quite sure it is compatible with a DX5e. Make sure the Tx and Rx are not too close together when binding and after binding when just turning on and connecting. Doing this near large metal objects like a car or metal top table can also interfere with binding and connecting. Don't point the Tx antenna at the Rx. The side of the antenna should face the Rx.

[simibill]

Originally Posted by kenchiroalpha

Hi
That RX is not compatable with the DX5 or DX6
http://www.spektrumrc.com/Products/D...dID=SPMAR6115E
Take care
Yours Hank

Not true.

[kenchiroalpha]

Originally Posted by simibill

Not true.

Hi
How so? its states on the site that it is not compatable with the DX6
** The AR6115e receiver is not compatible with the DX6 park flyer radio system
And the DX 5 use the same tech as the 6
Take care
Yours Hank

[simibill]

Originally Posted by kenchiroalpha

Hi
How so? its states on the site that it is not compatable with the DX6
** The AR6115e receiver is not compatible with the DX6 park flyer radio system
And the DX 5 use the same tech as the 6
Take care
Yours Hank

See post #2 to this thread. Which is a quote from Spektrum.

[Turner]

Originally Posted by kenchiroalpha

Hi
How so? its states on the site that it is not compatable with the DX6
** The AR6115e receiver is not compatible with the DX6 park flyer radio system
And the DX 5 use the same tech as the 6
Take care
Yours Hank

The DX6 is DSM and only compatible with the AR6000Rx.

The DX5e, DX6i, and DX7 are all DSM2 and are all compatible with current DSM2/DSMX air receivers.

[HobbyJumper]

Thanks everyone. Yes, the transmitter is a DX5e, so according to all the Spektrum literature (and the dude in hobby shop) it's supposed to work with that receiver, and most often, it does. Except when it stop communicating mid-flight!

I'll try some of the tricks mentioned and see if reliability goes up. I know I was doing the opposite of some of those tips.

Keep those suggestions coming if you got 'em.

[philipa_240sx]

HobbyJumper,

Losing a connection during flight is not a good sign. You may be having receiver or transmitter issues. I strongly urge you call Horizon Support and get this sorted out:

http://www.horizonhobby.com/Support/

(877) 504-0233

Hours of Operation:
Monday – Friday: 8:00 A.M. – 7:00 P.M. CST
Saturday: 8:00 A.M. – 5:00 P.M CST
Sunday: 12:00 P.M. – 5:00 P.M. CST

[kyleservicetech]

Originally Posted by HobbyJumper

Thanks everyone. Yes, the transmitter is a DX5e, so according to all the Spektrum literature (and the dude in hobby shop) it's supposed to work with that receiver, and most often, it does. Except when it stop communicating mid-flight!

I'll try some of the tricks mentioned and see if reliability goes up. I know I was doing the opposite of some of those tips.

Keep those suggestions coming if you got 'em.

What do you have for a motor battery, ESC, BEC, and how many and what type servos?

Just trying to make certain you are not having problems with "Brownouts" where the linear voltage regulator in your ESC is overheating and shutting down. That results in zero power to your receiver and servos. By the time you get to your model, that regulator has cooled down, and starts working again.

If my (lousy) memory is correct, the latest software in the Spektrum receivers flashes its LED if it detects a voltage sag on its DC input voltage. This can be checked by powering everything up, then unplugging the receiver power (or ESC and its BEC), and plug it back in again. The LED should start flashing.

[HobbyJumper]

Thanks Dennis and Philipa. I'm away from my plane for a couple of weeks but will follow up asap. You're right about needing to solve this one.

[jap71173]

Originally Posted by HobbyJumper

The AR6115e receiver in my eflite Jn4 just doesn't want to connect to my dx5e reliably. Turn on transmitter; plug in battery; sometimes it works great; sometimes it doesn't at all; sometimes it takes a long time. Today the connection was instant, but then was lost while flying! That was new. Lucky I didn't wreck my plane.

I'm a totally rookie when it comes to this new R/C stuff, and would appreciate any tips toward diagnosing and solving problems like this.

The equipment is all new and/or in good shape. Batteries good too. No problem connecting the tx to any of my UMs.

Thanks...

I like to solve problems by process of elimination...

My first thought is that you are losing connection due to interference coming from the plane itself (esc, motor, servos, etc.) and the receiver is simply going into failsafe mode. A very tedious but more accurate way test this theory is to:

1) re-bind your receiver but this time hold full right rudder as you do so... this will program full right rudder into your failsafe programming so that when you plane gets out of distance it will be very obvious as you watch your rudder flip to one side.

2) then, do a range check with your plane on the ground and the rudder visible to you as you walk away and follow the procedure for doing a full range check as per your manual. You should be able to get a minimum of 90 feet (30 paces) away from the plane without losing the link.Take special note of the distance it takes to throw your rudder out of whack.

3) next, reposition your receiver in your plane and repeat step 2

If the distance you lose connection is around the same each time, then the theory is false and the problem is not interference.

Regardless of results… don’t forget to re-bind the plane with the rudder at neutral or it may not crash very well if it ever did go out of range

***Note: I only use this rudder trick when I am alone and doing my range check… you don’t need to do this with the rudder if you have someone that can hold the plane and signal you when the plane loses its link.

The object here it to find out if the signal of your receiver is being interfered or obstructed by its position to other objects in the plane itself.

[philipa_240sx]

kyleservicetech,

'Brownout detection' only works on DSMX RX's operating in DSM2 mode or the more recent versions of DSM2 RX's. If the OP is using a DSMX version of the DX5e (it has DSMX written on the faceplate), then brownout detection is not available.

jap71173,

The OP is using an AR6115e which only has failsafe on the throttle channel. The other channels will retain their last commanded positions. Your procedure for checking possible interference issues using failsafes will not work. Fortunately the AR6115e features a HOLD led that will tell you when the RX has lost communications with the TX. The OP could do the same range test and simply check for a flashing HOLD led. I routinely do this with my planes.

[kyleservicetech]

Originally Posted by philipa_240sx

kyleservicetech,

'Brownout detection' only works on DSMX RX's operating in DSM2 mode or the more recent versions of DSM2 RX's. If the OP is using a DSMX version of the DX5e (it has DSMX written on the faceplate), then brownout detection is not available.
.

Good to know, all of my AR7000 receivers are DSM2, don't see any need to update them at our club field.

Wonder why the mfg dropped this brownout detection???

[Turner]

It's not so much that they dropped it. The way it worked with DSM2 is just not available with DSMX. I read a good technical explanation but can't find it.

This is from the Spektrum DSMX Addendum:

Following are the operational differences:
Brownout Detection - Not Available on DSMX Receivers
DSM2 receivers feature Brownout Detection that flashes the receiver’s LED if a power
interruption occurs. While DSMX receivers have QuickConnect and recover instantly
from a power interruption, the architecture of DSMX prevents Brownout Detection when
operating in DSMX mode.

http://www.spektrumrc.com/ProdInfo/F...ddendum_HR.PDF

[kyleservicetech]

Originally Posted by Turner

It's not so much that they dropped it. The way it worked with DSM2 is just not available with DSMX. I read a good technical explanation but can't find it.

At any rate, with all the information that's out there now on "Brownouts", that should not be an issue now.

IMHO, any model airplane using more than 2S Lipos really should have a separate BEC driving the receiver, especially if it has 4 servos or more.

ESC's like the Castle Creations ICE line have a built in switching power supply type of BEC that gets the job done.

As I've pointed out many times in wattflyer.com, my giant scale model with 7 Hitec 645MG servos pulled a measured 14 Amperes maximum current out of the receiver DC supply. That was measured with a $350 Fluke 87V digital multimeter with its one millisecond peak reading function.

So, with a 4 servo model with perhaps 500 watts of power on the prop, you could pull 6-8 amps out of the linear BEC's commonly used in many of those ESC's. That's borderline operation at the failure point.

[philipa_240sx]

kyleservicetech,

A sticking/faulty servo that is drawing excessive current could definitely cause issues like OP is describing. Definitely check the RX voltage with a DVM.

[kyleservicetech]

Originally Posted by philipa_240sx

kyleservicetech,

A sticking/faulty servo that is drawing excessive current could definitely cause issues like OP is describing. Definitely check the RX voltage with a DVM.

Thats a good point. Take a look at page 7 of the attached PDF file in this thread:

http://www.wattflyer.com/forums/showthread.php?t=52821

Sometimes those electronics have a problem when they've been on for a few minutes and things start to get hot. Along with that the current drain jumps. Good way to check for this is to power it up for 10 minutes with the digital meter monitoring current, and make certain that current drain doesn't change when the servo is not being moved.

Shot in the dark, but its fairly easy to test for.

[philipa_240sx]

I had a BEC/servo issue with 2 planes:

1) Cheap digital servo failed and caused the BEC to overheat and shutdown after a few min. The giveaway? The ESC kept beeping every few min indicating # of cells, presumably every time it reboot. That's when I found the heatsink was very hot.

2) Damaged a HXT500/SG50 servo by plugging it in backwards. Flipped the connector around to the correct polarity and the BEC would overheat within a few min and shutdown. It actually got so bad, the voltage regulators on the ESC melted the heatshrink wrapping!

[jap71173]

JR/Spektrum DSM2 Weakness Revealed

WHEN YOUR REDUNDANCY ALL BUT DISAPPEARS

Dated: 23 Feb 2010
While tidying up some of the final reviews for the great 2.4GHz Spread Spectrum RC system shootout, I discovered something very disappointing about the Spektrum/JR 2.4GHz DSM2 system.
As stated in the review, the DSM2 system is generally quite good. It uses two separate parts of the band and has a good degree of "spread" for each of its chosen frequencies, thus ensuring that under normal conditions, DSM2 provides a robust and resilient link between transmitter and model.
However, while doing a little more testing, so as to get a couple of extra screen-shots I discovered something surprising.
The 2.4GHz environment inside my metal-clad workshop is very clean. Being located some distance from the nearest population center and with the metal walls/roof providing excellent screening against external signals, the noise level is extremely low.
In such an environment, any 2.4GHz system turned on will see a band that is entirely free from potential interference and should therefore seek to take advantage of this.
In the case of the DSM2 system, that means I would expect it to allocate itself two channels that were separated by a good wide gap -- such that if one were hit by interference, the other would likely be well clear of the offending signal.

Well the spectrum analyzer scan above shows what I got when I turned on a JR DSX9 in this "clean" environment.
As you can see, on this occasion it has randomly chosen two channels but they are so close that they actually overlap.
Now, in a perfect world and in 99.9% of real-world situations, this won't be a problem and I should emphasize that the sky is NOT falling for JR/Spektrum users.
The reality is that because of the resilient nature of a spread-spectrum transmission it would still take a reasonably strong signal to knock out the link created by the DSM2 system, even with these closely-spaced channels.

In order to see what would happen when just such a "reasonably strong signal" was about, a video-transmitter was turned on and tuned so that it clobbered both of the narrowly spaced channels. A spectrum analysis of the video-transmitter on its own is shown above.
Using a 600mW 2.4GHz video transmitter, I found that the receiver only needed to be equidistant from both the DSX9 and the video transmitter's antenna for loss of control to be experienced. This surprised me a little -- I'd expected more resilience from the DSM2 system but, having said that, analog signals such as video transmitters are really not spread-spectrum-friendly.

The above image is a scan of the video sender and the original closely-spaced DSM2 signals interfering with each other. As you can see, the video transmitter's signal has almost completely obliterated both channels of the DSM2 system because they were too closely spaced.
When the two channels were spaced further apart (as is usually the case), so that one was not covered by the video transmitter's signal, the range of the DX9 radio was unaffected. However, on those rare occasions when they are close together (as in the image above), the effect of a modestly powerful video transmitter is significant.
This is not so good. In fact I think it's fair to say that it's not the kind of poor performance you'd expect from a "brand name" 2.4GHz radio system.
In effect, this means that if you were unlucky enough to have your Spectrum/JR radio select two closely spaced channels and someone was using a video transmitter on the same part of the band (effectively clobbering both DSM channels) then, should your model flew closer to that transmitter than it was to your own, you'd risk a lockout.
When the Spectrum/JR system selects two channels this close together, your expensive radio performs no better than a super-cheap FlySky radio, offering virtually no redundancy in the event of strong on-channel interference.
And, should this situation occur in the real-world, no number of satellite receivers, voltage regulators or other "bits" will help. Once the interfering signal overpowers the one from your transmitter, your model is at risk.
In testing, it appears that when turned on in a low-noise environment, the DSM system selects its operating channels at random and very occasionally (because those assignments are random), they happen to be almost on top of each other.
My question to JR is: Why?
Any sensible designer would have included a check to make sure that when the band allows for it, the two channels should always be spaced by a sensible amount. This clearly is not happening.
So, if you're a JR/Spektrum flier, should you sell all your RC gear and switch to something else?
Probably not. As I have said, most of the time the DSM system does select channels that are sufficiently spaced to provide a good level of redundancy and resilience. What's more, if you're flying in a relatively benign RF environment then the close proximity of the two channels that can occur on occasion won't have any effect. On the rare occasions when the JR/Spektrum radios do choose two adjacent channels, the effect is simply that your risk of lockout is increased but only if there just happens to be strong noise on that small part of the band.
However, if you have already encountered previously "unexplained" lockouts and failures at your field when flying DSM-based systems then perhaps this could be part of the cause.
As a JR owner (I have a 9XII/9303) I would not use Spektrum as my upgrade path to 2.4GHz unless they fix this flaw. While the odds of this actually causing a crash are low, they still exist and, given that it could be fixed with a minor software revision (that mandates a sensible minimum for the spacing of the two channels used), I see no reason not to suggest that such a fix be implemented.
With the onslaught of cheap (and increasingly good) Chinese-made equipment, much of which is now fully certified for use in the USA and EU, "brand name" manufacturers are going to have to step up their game if they want to retain marketshare. Even other companies with a strong global presence (such as Hitec) are now nipping at the heels of a technology that, in the case of DSM2, could do with some tidying up.
If you're a satisfied (or dissatisfied) JR/Spektrum user who'd like to have your say on this article, please email me and I'll append the comments below.
If JR/Horizon have an answer to the puzzling question as to why the system should significantly nullify the benefits of a dual-channel operation by allocating channels so closely spaced, I'd like to hear (and share with readers) that explanation.

[NJSwede]

Jap,

Luckily, the new DSMX technology completely eliminates that problem, since it's changing frequencies all the time. The worst that can happen is that you'll lose some single frames, which I think the receiver should have no problem correcting for. So if you feel this is an issue worth worrying about, just upgrade to DSMX!

[HobbyJumper]

All Eflite

SPMAR6115e DSM 6CH Receiver
10 Amp Pro Brushless ESC
S60 super sub micro servos (two of them)
2S 7.4V 430mAh battery

DX5e 2.4GHz DSM Spread Spectrum Technology. DSM2. That is what's printed on the tx.

Thanks

Oh and thanks for the pdf on DVMs. I've always owned one or two, but never learned how to use them, beyond checking battery voltage (incompletely).

Originally Posted by kyleservicetech

What do you have for a motor battery, ESC, BEC, and how many and what type servos?

Just trying to make certain you are not having problems with "Brownouts" where the linear voltage regulator in your ESC is overheating and shutting down.

[kyleservicetech]

Originally Posted by HobbyJumper

All Eflite

SPMAR6115e DSM 6CH Receiver
10 Amp Pro Brushless ESC
S60 super sub micro servos (two of them)
2S 7.4V 430mAh battery

DX5e 2.4GHz DSM Spread Spectrum Technology. DSM2. That is what's printed on the tx.

Thanks

Oh and thanks for the pdf on DVMs. I've always owned one or two, but never learned how to use them, beyond checking battery voltage (incompletely).

H'mmm
Far as I know, that should work, any other ideas from our readers???