mranga

My Feedback: (1)

Hello,

The following problem occured TWICEwith a spektrum AR-6200 receiver and once with a Hobby King Orange receiver (euqivalent in capability the AR-6200):

The plane is flying fine. Battery is fine. Lots of charge. Sudden and total loss of control.

Any clues on how to avoid it? The reboot time on the Spektrum receivers is pretty bad. More than enough time to crash a plane. Iam considering placing the satelite receiver outside the plane or having a piece of clear monokote from where Ican actually see the receiver to make sure it is not blinking before takeoff. Is this kind of problem caused by a bad binding (blinkig receiver)?

Iam wondering (seriously considering)giving up onSpektrum and moving to Turingy +FrSky as a result of these nerve wracking moments.

Any advice?

Thanks

Ranga

jester_s1

A brownout is when your voltage drops below the minimum that the receiver can operate on, which for Spektrum is 4 volts. You really can't know if your battery is up to the task until you hook up a meter to your receiver and put a load on a couple of your servos to mimic the current draw in flight. It's become common practice to use 6v packs with Spektrum equipment to handle the brownout issue.

The Turnigy/Frsky systems are NOT an upgrade from Spektrum. If you really want to get away from the Spektrum brand because you don't trust it anymore, Hitec and Airtronics have a very solid system that I haven't seen any reports of glitches from. Futaba doesn't suffer from the brownout issue but early units were sensitive to heat. In Maryland it wouldn't be an issue but some in the South had losses of control because of it.

mranga

My Feedback: (1)

jester_s1:Thank you for your quick reply. When you say Turnigy FrSky is not an upgrade from Spektrum, is that because they are less reliable? Idon't want to go from the frying pan to the fire. It appears they use frequency hopping (like Futaba) and fast reboot.

pdm52956

My Feedback: (1)

What battery pack are you using?

How did/do you know it isn't a battery issue?

Did you determine there isn't another problem....like a switch?

These are some questions I think need to be answered in order to help determine what might have happened. That isn't to say that any reply you get is going to be the tell all answer. I doubt anyone here was there with you so it's all guess work.

I fly Spektrum and JR and have never had any kind of issue that I didn't cause. That isn't to say you won't have issue with whatever you have that is Spektrum, just that tooooo many times I hear this or that eluding to radio problems when it isn't the case to begin with.

If you're ready to jump to another brand after one incident that you have yet to determine what caused the problem to begin with, I say go for it. Any brand would be better than not knowing right?

Just my .01.

DadsToysBG

My Feedback: (35)

Juster just to clear the air. All Spektrym/JR receivers can go down to 3.2v. at this point the servos won't work. all reboot is in mils. Also all new radios and receivers by Spektrum and JR hop. Read the following link on testing the X.
http://www.rcmodelreviews.com/dx8dsmxreview.shtml
Dennis

mranga

My Feedback: (1)

Iam using a 4.8 V NiMh battery pack. After the crash, Itested the battery pack and it was fine. Isuppose Ishould go up to 6 V.


No Idid not. It could have been. It is difficult to tell. However , Idid note that the previous TWO crashes (AR 6200 receiver)happened at the same spot on the field. Ijust want to know if not having a "solid" red light indicating a good binding with the transmitter (i..e. blinking light)could cause such a problem. If so, I'll put a little hole on the model where Ican see the receiver.

Rodney

You can get a brownout even if you have a perfect battery. It is the voltage on the receiver bus that counts and that can be quite a bit less than the battery voltage. If the wire gage between the battery and receiver is to small or if the length is excessive or if the switch contacts are high resistance there will be a voltage drop between the battery and the receiver. Now it the servos put a sudden demand (you just commanded all of them to move at the same time and the air loads are high) the additional current demands drop the voltage on the receiver bus. This only need to last for a few microseconds to cause a brownout. You can not measure this using a typical meter, you must have an oscilloscope or some equivalent instrumentation to measure these short duration voltage drops. A Voltwatch comes close to meeting this demand. If you have the Voltwatch connected right on the receiver bus (no Y's or extensions) it responds quite fast. If you see the LED's dipping into the red when you cycle the sticks, it tells you that you have a wire, switch or battery problem or a combination of them. A Voltwatch is almost as good an indicator as an oscilloscope.

pdm52956

My Feedback: (1)

First off, take that 4.8 battery and put it back in the tool box. Please use a 6 volt battery with a Spektrum rx.

Secondly, when you checked the battery after the crash, did you use a meter that could put a load on the battery? If you don't have one, it would serve you well to get one. When a battery is checked in an unloaded state, you may get what you think is a good reading but once a load is applied, the voltage shows a drop and you may go below 3.2 which is what the threshold is. That will cause a "brown out" and once that occurs, the voltage will go back up since there isn't anything drawing from it. Voltage goes up......servos work.......but then voltage goes back down when you move the sticks! Never ending cycle until the ground gets in the way.

The blinking light on the rx indicates power was "interupted" for some amount of time and it really doesn't indicate a bind issue. If the light was blinking, then yes, it would be an indication that you had a power drop and it could have been the reason you lost control for some amount of time.

There are a number of different battery types out there and I'm not saying you need to change to another type, but I would certainly recommend upping the voltage to a 6 volt pack if your going to stay with Nimh.

Hope that I've helped some. If not, you wouldn't be the first to tell me so.......my wife would!

MinnFlyer

My Feedback: (4)

Ditto

DadsToysBG

My Feedback: (35)

There are a lot of questions to answer. What was the MA of the battery? How many flights on the battery? How new or old were the switch and servo extensions? Have you cycled the battery?
On another forum there was a thread on power needs for Gs planes with hi-end servos. This probability doesn't apply to you, but it was found that a 100cc plane at idle was drawing 2 to 2 1/2 amps at idle on the runway and after a hard 3-d flight the power piked at 19amps. We also showed the the standard servo plug caused a 1/2v drop each.
On our 2.4 receivers power is everything and must be watched very closely. A 4.8v battery must be recharged when it shows 4.8 because under load it will drop lower. Same goes for 6v.
Standard servos won't have the amp draw as the high end ones, but still old wires, old switches can cause a voltage drop before it even gets to the receiver.
This apply s to all the 2.4 radio systems. Dennis

jetmech05

You can not detremine the state of the charge of a battery without a load.....a battery that is almost dead can read a preety good charge until you put a load on it then it will drop way down...get too low and a brown out occurs...get a 1000 mAh 6.0 V battery

Gray Beard

My Feedback: (-1)

A question for you: Over the years Spektrum/JR has been known to have a brown out problem. There was a call back/ warning on the JR site about the long reboot problem with the original RXs and you could get them replaced. It was suggested that the 4.8 volt battery not be used and people should use 6 volt packs. Still, when you bought a new radio the 4.8 volt pack was included. Last new radio I saw still came with a 4.8 volt pack.
Why doesn't JR/Spek send out new radios with a 6 volt pack? I have been told JR/Spek has changed there system and is now more in line with the Hitec and Futaba in the way it sends and receives the signal?? I have been told if you have an older radio it can be sent in and be upgraded.
Just wondering? An inquiring mind wants to know. All I seem to get is rumors from the field.

kiwibob72

Mranga, taking into account your statement "I am using a 4.8 V NiMh battery pack. After the crash, I tested the battery pack and it was fine. I suppose I should go up to 6 V. ", I have been running that exact AR6200 receiver on a 50 sized nitro heli for over two years now (5 high torque digital servos and a gyro all running at once), but with a 6v Nimh pack that was new at the time, and not once have I suffered a single brown out issue or something even remotely related to a glitch. On that basis, I'd say you have hit the nail on the head re your problem!

DadsToysBG

My Feedback: (35)

To be honest even the techs at Horizon didn't have a good reason for the 4.8 battery being included. Now no radio system sold has a battery with it.
(2) When they first released their 2.4 the egg heads that designed the system never thought that people would let their battery's get to low. Too them it was a nobrainer that you keep your battery's in top condition. When they saw that the consumer was not doing this they went back and redesigned their receivers with a quicker reboot time.
(3) Yes you can. All new radio's are X that will work with the older S. All the new receiver's are X that will work with S radio's. If you fell it is important you can upgrade. As time passes all the JR/Spektrum will be X as older receivers and radio's are retired. If you haven't had any trouble as I haven't there's no need for the upgrade.
I have a X radio now but I'm still using the old S receivers that have the old reboot time.
I fly GS planes and have learned about the power demands of these type of planes. I have both planes out of the trailer and I am in the process of re wiring them and adding a power panel to get better power distribution to the servo's.
It's a continuing learning process and improvement and as I learn more I make the changes. Dennis

gofast53

Precisely why I ditched my Spectrum gear and went for a Turnigy with FrSky module, as I use to have numerous brownouts and slow relink times (using latest version Spectrum 6200' with satellite) and never found a reason or resolution. Even sent my gear back for testing but no problems found, yet other people I know with the same gear have never had an issue. I fly large scale gas and use the FrSky telemetry recievers with peace of mind, been using them for 6 mths now with no problems at all. Pricing is great on the recievers and the Turnigy transmitter with upgraded firmware has so many possibilities in regards to mixing setups.
There are mixed feelings on my setup but I have found that those that are negative have no experience with this setup. I guess it all comes down to personnal preference and whether or not you feel comfortable in using a $150 radio on an expensive model.

OobedoobeR

i had the same problems but with a six volt 2000ma battery. checked all after a crash. even put it in browout on purpose to see how
long it takes to rebind an it never rebinded. so the answer i have is use it as a buddy box and buy another brand as i did.
that solved my problems.

Fs one

I have 2 giant planes i fly using ar7000 receivers i use 4.8 receiver packs one 1400mah the other 1100 mah have never had an issue both these planes highly used for three years now.These are nicad packs.If you are not using high high torque servos should be no problem.Using 6 volt packs will give you a little more speed on the servos.

llindsey1965

My Feedback: (-1)

i had a problem this weekend with my 2200mah nimh  ignition battery  fly 6 flights  motor ran very good  , 7 flight started motor was rough and popping , checked with volt meter it tested 4.8 volts  pressed the load button and it went to 3volts  ,always load test those batteries  , or you could lose a airplane

osxpro

My Feedback: (51)

A brownout is when your $3K plane is 200' up and you lose your radio.. The result being a complete brownout of your underwear!

zacharyR

My Feedback: (5)

FYI LOAD TESTING IS SOON TO BE A THING OF THE PAST

JeffinTD

One other thing that can contribute to brown out is having a servo lock up, bind, or short out internally. They can pull very high current.

jetmech05

Can you expand a wee bit more on the statement that load testing will be a thing of the past

Propworn

My Feedback: (3)

Brownout caused by eating to many prunes.

Rockin Robbins

I don't know whether your plane is electric or internal combustion. It IS important to the question, you know. I come from the electric side of things. There brownouts are always not far from our thoughts, no matter what kind of radio we use. The battery elimination circuits in our electronic speed controls often are not robust enough to provide the amount of power our radios and servos will draw. If your radio and servos at peak draw, with four servos drawing power at the same time needs more amperage than your battery elimination circuit can provide, you get a voltage drop, no matter what condition your batteries are in. It also doesn't matter what kind of radio you have, you can brown them all out.

All you have to do is draw more amperage than your battery or battery elimination circuit can produce and your voltage will drop. When it does, there's a point where your radio quits working.

Have you considered the possibility that you didn't brown out at all, but were masked by some object opaque to radio waves, like a power line, possibly a fence, or even the earth itself? I've been shot down going behind a hill with 2.4 Ghz equipment. It is strictly line of sight and LOTS of things can break that line. Again, the brand of radio doesn't matter there.

mranga

My Feedback: (1)

Turnigy also claims to put out a higher power signal from the transmitter. The FrSky receivers appear to give you quite a bit of bang for the buck.