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-   -   DX8 Question (http://www.rcuniverse.com/forum/questions-answers-154/11199620-dx8-question.html)

bikerbc 08-20-2012 07:08 AM

DX8 Question
I had somthing wierd happen at the field Sat...I fireded up my 1/4 Cub and taxied out and had a flame out....I went out and grabbed it by the tail and pulled it back in for a restart and when I got it back I noticed that none of my controle surfaces were working . The throtle was working but it was very slugish...I played with it for a few mins to make sure I wasent mistaken and checked to make sure my switch was fully on...I shut both transmitter and reciever down and turned them back on and everything was working started working properly again....It has me worried...It could happen again at any time... Has anyone had this happen with Spektrum? I am going to do a rebind and am thinking of maby changing recievers....I am using a Spektrum AR 7010 reciever... It is new ,had maybe 10 flights on it but never been in a crash or anything like that....The battery was fully charged 2500 mahNi Cd ......Any thoughts on this? Thanks

acdii 08-20-2012 06:48 PM

RE: DX8 Question
Only way to know would be to look at the RX when it happened to see if you had a brownout, or lost link. There are LED's to indicate it.  Hard to know  at this point.

bikerbc 08-21-2012 11:39 AM

RE: DX8 Question
Well I have called Horizon and the Tec has instructed me to send them both the transmitter and reciever for testing....This is the second time for this transmitter...I am not all that happy with Spektrum at this point....I dont know if I will ever trust it again....I will say they have been good about warranty and the last time they sent me along an extra reciever as a gift for my troubles...I thought that was very nice ....

huck1199 08-21-2012 12:37 PM

RE: DX8 Question
Was the AR0710 blinking? If so you lost signal - lose wire, brownout, or TX hiccuped (problem).

bikerbc 08-22-2012 09:16 PM

RE: DX8 Question
The AR7010 is buried under the cockpit floorso it is difficultto see ....I can see now that it is an important source of information that should remain accessible...i Will rember ..I hope

Rotten40851 08-23-2012 02:24 PM

RE: DX8 Question
A problem with a Spektra system? I don't believe it!!! When will you people learn?!!!!

acdii 08-24-2012 05:36 AM

RE: DX8 Question
I have several planes on my DX8 with Spectrum RX, and the only time I ever had a problem was due to a bad ESC. I have dozens of flights on my DX8 without any issues.  Before that I used a DX6i, same thing, never had a problem. Can't generalize saying Spektrum products are all bad. There are problems with Futaba, Airtronics, JR, etc. too. <div>
</div><div>For the most part these problems turn out to be user created due to lack of knowledge in setting the RX up correctly, or not using the correct connections, or servos. </div><div>
</div><div>Case in point, I thought my Futaba RX had gone bad when the servos were glitching and not responding, and the TX link LED kept blinking. Turned out to be a loose battery connection, even though I had a clip on the connector, the vibrations from the motor was causing it to break connection.  I was about ready to rip the RX out and put another one in when I found the problem. One of the pins wasn't fully seated in the plug. It was that simple. </div>

SeamusG 08-24-2012 08:31 AM

RE: DX8 Question


ORIGINAL: Rotten40851

A problem with a Spektra system? I don't believe it!!! When will you people learn?!!!!
Ihave a DX7 (5 years), 8 Spektrum Rx (AR6200 &amp;AR7000) - problems - zero. Uh, that was <span style="font-size: x-large;">ZERO.</span> Was I clear? <span style="font-size: xx-large;"><span style="font-family: Comic Sans MS;">ZERO!</span></span>

What do I have to learn?Please share as I'm very much into learning new stuff - it's my life long quest.

GoBeach75 08-24-2012 03:49 PM

RE: DX8 Question
I don’t know a lot about Spektrum, but I fly Airtronics and haven’t had any problems with it ever. I fly with an SD-10G and it is a great radio. A lot of people in my club fly Airtronics, too. If you do decide to make a switch in your radio system, I would recommend the Airtronics line.<div>

Bluelt 08-24-2012 05:26 PM

RE: DX8 Question
Bikerbc,  <div>I had the same experience.  I was using an old 4.8 nimh pack (that I only use on the bench)  to set up the servos in an electric plane .  The controls worked very sluggish.  Checked the battery and it was way low.  Charged battery and finished set up the next day.  Didn't think much about this until reading about your experience.   ???</div>

SeamusG 08-24-2012 05:48 PM

RE: DX8 Question
If ya check your battery's voltage with a "load" type volt meter you can see 1) if your voltage is as expected and 2) if you have a bad cell. It's the 2nd that can bite you as it charges to a full voltage (maybe 5.70 for a 4.8 v pack) but when you put a load on it the reading shown on the meter is not steady - but declines as you keep the load on the pack. I had one that dropped to 4.2 v in about a minute (from 5.7+). Other packs show a solid 5.6 v with the load. Release the load - back to 5.7. Hit the load - back to 5.6. Both readings are dead solid.

Many of the Spektrum "problems" have been due to momentary Rx brown outs where the available voltage to the Rx drops below 4.4 (the pack's nominal voltage). At that point the Rx is "on its own" until the voltage is above that line - then it reconnects with the Tx. The Rx will be flashing to show that it went into brown out mode (it the plane recovered). There was a firmware upgrade available for Spektrum Rx to shorten the "brown out recovery" time from nearly 5 seconds to maybe 1 second. I sent all of my Rx to Horizon for the free upgrade. Quick turn around too. Many users simply moved up to 6 v. packs (me included for the most part) which also has the benefit for increasing the speed of your servos as well as available torque. A bad 6 v. pack may well cause a brown out too but that's more or less on the "pilot" for not keeping an eye on his battery pack's health.

Kinda funny that the Spektrum "car guys" have used capacitors that plug into an open channel on the Rx - manufacturer of the capacitors? Why Spektrum of course. But they never added them to the airplane menus. Go figure.


bikerbc 08-26-2012 01:13 AM

RE: DX8 Question
I was using a 4.8 V batt pac in my plane. It is a new pac but still I think I might be better off with 6 V pacs...I really wish I had pulled the floor out of my plane and had a look at the RX...I am not ready to Bash Spektrum..Spektrum has flowen my planes around for 3 yrs with no problems...I am more than likley the problem....Mayby the Batt pac should have been 6 V or somthing like that....This transmitter was recalled just after I bought it .Other than that it has worked fine....I dont think rude posts like when will we ever learn serve any usefull purpose...When will you ever learn manners?

SeamusG 08-26-2012 07:41 AM

RE: DX8 Question
Biker - Manners? We don't need no stinkin' manners (just kidding of course) - need a "smiling" font so ya can see the typer's facial expressions.

A thought - where's your remote receiver? It also has a light on it that mirrors the primary Rx light. So it's not so important to have the "expensive" bit exposed - just one of them. Also, can you explain the antenna orientation of both the primary and remote Rx components?


bikerbc 08-27-2012 04:34 AM

RE: DX8 Question
My Main Rx is mounted on foam against the fuse sidewith the antennasvertical , the satilite is aprox 3 ins away mounted on foam againsta formerwith the antennas horizontal. You are rite I could have mounted the sat out where it could be seen..I think I will relocate it when I get it back...Thanks for the pos inputt . ...

SeamusG 08-27-2012 06:19 AM

RE: DX8 Question
I've been successful mounting the remote using thick double sided tape. I prep the wood mounting location with a wash of alcohol diluted epoxy - makes for a nice smooth long lasting mounting location.

bikerbc 08-27-2012 10:49 AM

RE: DX8 Question
Yes that is how I do it too. Or somtimes I will use that Hook and loop stuff ..Mostly I use the two sided tape though...You get the foam vibration dampening included

acdii 08-27-2012 06:46 PM

RE: DX8 Question
I use the heavy duty hook type where both sides are the same, and uses a thick cushion adhesive to mount the RX and sat. Works good because I can switch out RX between planes if I want to change up which radio I want to use.

jetmech05 08-27-2012 11:05 PM

RE: DX8 Question
after reading all this if it were me.....I'd never fly Spektrum without a 6 V battery....and I'd change out the on/off switch.....just to be safe...switches fail more than a battery or a receiver.....alway always check battery voltage under a load.....and get the receiver out of it's hidden location.....could it be getting hot under your cockpit?

bikerbc 09-29-2012 06:21 AM

RE: DX8 Question
First of all thank you guys for all the inputt...I have now recieved my Radio back from Horizon...They forgot to send me my reciever but they are going to send me one ASAP...They also sent me a Digital Variable Load Voltmetre for checking my batteries (as a gift) and a Digital Servo&Reciever Current Meter(olso a gift) However they couldnot find anything wrong with my radio or reciever...I notice on the work sheet that transmitter gimbals have been worked on or replaced The Tec suggested I test my Batteries etc.etc. I have since used my new Batt tester and my batt seems fine...I have decided however to go to a 6 volt battery as some of you have advised and I have replaced my switch with a new one just in case... I have a new reciever so all is installed and working fine at this point...I will be doing my test flight this afternoon weather permitting...So far ot looks okay...It takes till noon for the sun to get high enough to be out of your eyes at our field...This Cub is a dream to fly and I really love it but I am nervous because I don't trust my radio....I am sure it will be okay , I hope I hope....I have an Aurora 9 on order and I think it is sitting at the border so it will not be long and I will have a new radio.....I still like my DX8....I sure would like to know what happened...one other thing I have read about is you are not supposto be to close to your reciever with your transmitter...Something like 4 feet...I was closer than that....Thanks again...If it goes south on me I will let you know.....You can bet I will Range check and taxi up and down the runway a few times before take off....

acdii 10-02-2012 05:11 AM

RE: DX8 Question
I can tell you it doesn't take much to brownout an RX now. I have a T-34 that used to be electric and had the ESC get warm enough to drop the voltage to the RX and cause brownouts, even though the pack was fully charged.  Not the fault of the radio, its just the nature of the beast.  I now fly the same plane with a glow motor and a 5 cell Nimh on the same RX as before and have not had a single brownout, so I know for sure it was the ESC.

jester_s1 10-02-2012 05:31 AM

RE: DX8 Question
I'll have to disagree Acdii that it's not the fault of the radio. JR/Spektrum knows what the standard RC equipment in the hobby is, and they designed and marketed a system that cannot work with a significant amount of it. 4.8v batteries are common, as are 5v BEC's on speed controllers. They know that sometimes servo draw causes voltage to dip below 4v, and they know that many pilots never realize it. All the other manufacturers took this into account and designed systems that wouldn't brownout in those conditions, but somehow JR/Spektrum continue not to. I gave them the benefit of the doubt until the DX8 came out and had to be recalled for reliability problems after only a month or two of being on the market. In today's RC market, there are simply too many well-designed, reliable products to mess around with a brand that isn't.

RCPAUL 10-02-2012 06:21 AM

RE: DX8 Question
Do other brand 2.4 radios have brownouts?

pdm52956 10-02-2012 07:15 AM

RE: DX8 Question


ORIGINAL: jester_s1

In today's RC market, there are simply too many well-designed, reliable products to mess around with a brand that isn't.
All things being even, I haven't had the first problem with either my 6i or my 9503. I did have one plane go in and would have sworn it was the rx or tx but after further investigation found out that it was the switch!

So that said, does it make it right to say that you're all wrong in your conclusion because I haven't had any problems? Not any more so than you saying there are problems with all the whole line because you had a bad experience.

All that would do is start one of those silly internet arguments that neither of us would win.

So, since I've not had any issues using my Spektrum/JR equipment, you must be incorrect in your analysis.........

Just saying.

bikerbc 10-02-2012 11:39 AM

RE: DX8 Question
I started this by asking a question looking for help. The last thing I wanted to do was or is start a Who's is bigger debate... Since my last post I have Re Maidened my 1/4 Cub with a new switch , A new 7010 reciecer , and I changed over to an 1100 mAh A123 reciever pac ...I did a good range check and went for it...It flew beautifuly....I have 6 flights on it with no hint of problems.....I still have that worried feeling while my plane is in the air though ....I have purchaced a Aurora 9 and it is sitting at the border waiting for me....I may end up switching over....I hope not.....Thanks to all for your advice and the positive feedback ...DX8's are still pretty good radios I think...I am hoping my problems were related to my wireing , like my switch or somthing...The Battery is definitely suspect . There is enough Terrorizing going on in this world with out me Terrorizing Spektrum or the DX8's because I had a little problem that I could not easily identify....

pdm52956 10-02-2012 12:06 PM

RE: DX8 Question
Great news! I'm glad it all went well. My guess is that the switch or battery was the culprit. I think you'll find that the DX8 will serve you well provided it, and it's needs are looked after. Most of the time, the plane and radio will talk to you and tell you something is going wrong. We just need to listen closer.

Good Luck.

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