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-   RC Radios, Transmitters, Receivers, Servos, gyros (https://www.wattflyer.com/forums/forumdisplay.php?f=68)
-   -   HELP! Spektrum DX7 radio failure? (https://www.wattflyer.com/forums/showthread.php?t=22015)

flypaper 2 08-15-2010 01:24 PM

Had to send mine in to get the ant. replaced. Plugged the stock batt. back in. Don't tell anybody.:D

Gord.

jbfalconer 08-15-2010 02:38 PM

Certainly with my DX7 woes, I have not been using a lipo for the transmitter, When I use a separate receiver battery I have used only the Spektrum NiCad pack, either 4.8 1500 ma or 6.0 2700.

Lieutenant Loughead 08-15-2010 05:07 PM


Originally Posted by celticflyer (Post 742148)
In all these posts that have had trouble with DX7s, has any of you used lipo batteries?
If you check with Horizon, this will void your warranty.

Stock battery only. As a matter of fact, the stock battery has never been unplugged since I bought mine.

However, I'm at a point where the stock battery just isn't lasting long enough for a couple hours of flying. I'm getting ready to upgrade to a 3s LiPo.

I think Spektrum will void the warranty because it would be VERY easy to plug in the NiMh "wall wart" charger to charge the internal (unseen) LiPo battery. The result would probably burn your house down -- so Spektrum limits their responsibility by simply saying, "Don't do it." :rolleyes:

flypaper 2 08-15-2010 05:25 PM

First thing I did on my DX7 when they first came out, was to reverse the wiring on the charge plug on the inside of the trans so I could charge both the Futaba and Spektrum with the Triton without being concerned about a reverse connection.
I put a diode in the line when I went to the lipo batt. to drop the voltage a bit. No problems for more than a yr., including leaving it on all night and killing the batt. flatter than P on a plate. :DPut it on NIMH charge till it got over 3 volts per cell, then put it on lipo. Been fine since I did that about 8 months ago. I see the new DX8 will take both NIMH and lipo with a built in charger that can differentiate between the two. Mine is on order.:p>

Gord.

Lieutenant Loughead 08-15-2010 09:53 PM

I've thought about the diode modification -- but I'm concerned about the solder points giving out and then I have NO power to the system at all.

Again, I'm concerned about the "Scotty statement" that the more you add to the system, the more points of failure you introduce into the system... :oops:

silverfox123 08-25-2010 04:58 AM

DX-7 System Problems
 
Just learned of this website after a flying buddy told me about it since I have started having problems with my DX-7. Have had the system since Sept. 2007 and been pleased with it. Recently I have started having a lack of control response at times during flight with different planes and receivers. My UltraStick 25e (AR6200 and BEC receiver power) has crashed several times after it would not respond to control inputs. Repaired it and have had several times where it would not respond but was high enough that I regained control after working the sticks (I thought that by cutting the throttle and bringing it back up caused it to regain control). I have had other flights with it without problems. But after reading this thread I wonder if it just restored receiver control on its own. Several weeks ago, I crashed and destroyed a Great Planes Escapade, same cause but it had a charged 4 cell separate receiver battery and a different AR6200 receiver. Last week, crashed and destroyed a Pulse 60 (same cause but different AR6200 receiver and different separate charged 4 cell receiver battery). Began to think it was a problem with the AR6200 receivers. Yesterday, crashed and destroyed my beautiful Inspire 90 pattern plane (AR500 receiver and a charged 5 cell receiver battery). Called Horizon customer support immediately after the last crash and asked about reported similar problems and was told they had not received any. After reading this thread, I guess they lied. They told me to send in the transmitter and receivers and they would check them out. I now believe that my transmitter has a component that is failing and causing an intermittent failure and the Horizon analysis will not find the problem, unless it is something like a crease in a coax cable I read about in this thread. I have been using a 3 cell Common Sense LiPo transmitter battery for a year or so and it was charged the night before my last flight and showed about 12 volts. I usually fly during the day (retired) and there was only one other flyer at the time and we alternate being in the air. The latest crash was at the opposite end of the flying area from the other crashes. After considering all things and reading the first 10 pages of this thread, I suspect my transmitter.

I have several other Spektrum receivers and have not had problems untill recently. Therefore, I am thinking of sending the transmitter and receivers from crashed planes to Horizon just in case they can find something. I am thinking about buying a new DX-7 transmitter because I don't trust the current one and hate to switch to a new system when this one worked well for almost 3 years and I have other Spektrum receivers in other planes.

I thought I would throw this into the mix on this thread in case anyone starts to have problems, you may not want to continue to risk planes until you figure out the problem (my bad). :{ If anyone has other ideas about this problem, lets hear them.

Saddlebum 09-19-2010 01:29 AM

Crashed my E-Flite Beaver on landing leg.

Had 1/4 throttle, had made the final turn and on approach she SNAP ROLLED into a double spin straight into the ground. I had no control.

Totally destroyed. Had about ten hours on her, all trouble free until today.

E-Flite components; Motor, ESC and AR7000 Reciever, four months old.

Battery had 53% of power left and transmitter had plenty of juice also.

Not my thumbs or the wind and no, I didn't stall it.



Anyone have any ideas?

...The Bum

rcers 09-19-2010 01:38 AM

While I loved my eFlite Beaver, I found myself getting slower and slower with it, and suspect airspeed, not equipment was your issue. I had just the same thing happen, and I know it was "too slow". :(

1/4 throttle might have been it. Did you have flaps deployed?

Mike

Saddlebum 09-19-2010 02:48 AM


Originally Posted by rcers (Post 751045)
While I loved my eFlite Beaver, I found myself getting slower and slower with it, and suspect airspeed, not equipment was your issue. I had just the same thing happen, and I know it was "too slow". :(

1/4 throttle might have been it. Did you have flaps deployed?

Mike

Yeah, full flaps. I had been doing practice approaches and this was my eight time around with full flaps.

It certainly could have been me but... I have practiced a lot of slow speed turns and stalls at altitude and all of them were more gentle, like falling off a wing.

This time it was a snap roll; the kind of manouver you get if you slam full left aileron and full left rudder at the same time.

Did your fatal crash do a snap roll?

...The Bum

groundrushesup 09-19-2010 04:29 AM


Originally Posted by Saddlebum (Post 751060)
This time it was a snap roll; the kind of manouver you get if you slam full left aileron and full left rudder at the same time.
...The Bum

Or the kind you get with too little airflow over the wing and nothign to counteract motor torque :{

rcers 09-19-2010 07:21 AM


Originally Posted by Saddlebum (Post 751060)
Yeah, full flaps. I had been doing practice approaches and this was my eight time around with full flaps.

It certainly could have been me but... I have practiced a lot of slow speed turns and stalls at altitude and all of them were more gentle, like falling off a wing.

This time it was a snap roll; the kind of manouver you get if you slam full left aileron and full left rudder at the same time.

Did your fatal crash do a snap roll?

...The Bum

Full flaps and 1/4 throttle was very likely the issue. Sorry man.

The flaps on the Beaver were remarkably effective. They create a huge amount of drag with that increased lift and you need a bunch of power.

And will full flaps I am sure you noticed how soft the aileron's authority became. Use of the rudder was essential! In fact I used more rudder than aileron for turns anytime I used over half flaps.

The other issue, and was a contributing factor to my first Beaver's crash was I had a touch of asymmetric throw as well. Even a tiny bit can kill a plane.

And yes my Beaver snapped then it did a really nice cartwheel. It was not a fun day.

Sorry for your loss.

Mike

Saddlebum 09-19-2010 06:03 PM


Originally Posted by rcers (Post 751106)
Full flaps and 1/4 throttle was very likely the issue. Sorry man.

The flaps on the Beaver were remarkably effective. They create a huge amount of drag with that increased lift and you need a bunch of power.

And will full flaps I am sure you noticed how soft the aileron's authority became. Use of the rudder was essential! In fact I used more rudder than aileron for turns anytime I used over half flaps.

The other issue, and was a contributing factor to my first Beaver's crash was I had a touch of asymmetric throw as well. Even a tiny bit can kill a plane.

And yes my Beaver snapped then it did a really nice cartwheel. It was not a fun day.

Sorry for your loss.

Mike

Good information and explaination, Mike. Thanks.

I understand now it was my own fault but as we say at our flying field; "Every crash is an opportunity to buy something bigger, better and more expensive!"

mclarkson 04-05-2011 05:39 AM

Since this seems to be the default DX7 thread, I'll ask this here. Point me elsewhere, please, if I'm derailing.

Got a DX7 a few weeks back and I'm kinda hating it. It seems so very hard to do simple things, compared to my DX6i. Model Select, for example: do I really have to turn the Tx off, then hold two different buttons down while turning the TX back on just to select a model? It's so awkward.

celticflyer 04-05-2011 05:51 AM


Originally Posted by Lieutenant Loughead (Post 227450)
Hi.

I had two lockout radio failures on my Spektrum DX7 radio this afternoon.

Do you know what caused this?

Spektrum DX7, AR6100, Phoenix 25 ESC.

The first lockout radio failure recovered in 10 seconds.

The second lockout radio failure recovered in 25 seconds. The airlpane almost hit the ground!

Please help! :blah:

Have you by chance been using a lipo battery in your TX???

kyleservicetech 04-05-2011 06:03 AM


Originally Posted by mclarkson (Post 798655)
Since this seems to be the default DX7 thread, I'll ask this here. Point me elsewhere, please, if I'm derailing.

Got a DX7 a few weeks back and I'm kinda hating it. It seems so very hard to do simple things, compared to my DX6i. Model Select, for example: do I really have to turn the Tx off, then hold two different buttons down while turning the TX back on just to select a model? It's so awkward.

That's the only way I know of. But, it's nice to know you absolutely can not accidentally change from one model to another while FLYING your model :D :D :D

ministeve2003 04-05-2011 06:05 AM


Originally Posted by mclarkson (Post 798655)
Since this seems to be the default DX7 thread, I'll ask this here. Point me elsewhere, please, if I'm derailing.

Got a DX7 a few weeks back and I'm kinda hating it. It seems so very hard to do simple things, compared to my DX6i. Model Select, for example: do I really have to turn the Tx off, then hold two different buttons down while turning the TX back on just to select a model? It's so awkward.

yup, it's easy once you get the hang of it... at least it doesn't have a cheap @@@ scroll wheel that breaks when you look at it...LOL

SK

kyleservicetech 04-05-2011 06:08 AM


Originally Posted by celticflyer (Post 798657)
Have you by chance been using a lipo battery in your TX???

Interesting question.

Pure speculation here. IF (And a BIG IF) the Spektrum transmitters use a linear voltage regulator in their circuitry, and IF that regulator gets to hot as a result of to high of a battery voltage from a Lipo battery, results could be interesting.

Radio loss for 10 and 25 seconds sure sounds like perhaps some voltage regulator either in the transmitter, or the voltage regulator in the ESC got to hot, and shut down to protect itself.

Anybody out there familiar with the power supply circuitry of the DX7 transmitters ????

celticflyer 04-05-2011 06:17 AM


Originally Posted by paranoia (Post 235565)
I had the same problem with two of my planes, the 1st without a BEC and the 2nd with. The 1st plane when in to level flight the second plane crashed.

Both planes when in line of site, with no trees or structure even in the area


1st plane was at 50ft away, the 2nd was about +250ft.

both times the antenna was pointing at the plane

I sent my Rx6100 for upgrades which was done.


THIS IS THE ANSWER TO MY PROBLEM WITH THE SYSTEM
I don't think it was the upgrade that fixed this problem, my DX7 came with a battery that was self discharging very quickly(bad pack), (which they wouldn't replace)!!! and i don't think it was providing the power the Tx need to keep contact with the little AR6100. Even with the AR6100 at the correct power level, which i checked after each problem.


So with my new working battery the voltage/amps are correct and so far I haven’t had another problem…..

Note the voltage displayed looked okay but the amps the pack was putting out was very low.

"Both times the antenna was pointing at the plane":eek:
Big problem. That is the weakest signal. Bend antenna up or to one side.
Mine will loose signal pointed at the plane, but I keep it bent 90 deg to the right and have never lost a plane to weak signal. I have about 800 flights on my DX7. I've seen a lot of DX7s operate flawlessly. I've had people tell me they had a glich and lost signal, but in a couple of cases it was an excuse to cover up dumb thumbs.:rolleyes:

celticflyer 04-05-2011 06:20 AM

PS see post #75

celticflyer 04-05-2011 06:27 AM


Originally Posted by kyleservicetech (Post 798664)
Interesting question.

Pure speculation here. IF (And a BIG IF) the Spektrum transmitters use a linear voltage regulator in their circuitry, and IF that regulator gets to hot as a result of to high of a battery voltage from a Lipo battery, results could be interesting.

Radio loss for 10 and 25 seconds sure sounds like perhaps some voltage regulator either in the transmitter, or the voltage regulator in the ESC got to hot, and shut down to protect itself.

Anybody out there familiar with the power supply circuitry of the DX7 transmitters ????

I'm not familiar with the circuitry, but had a bench problem. My programing started acting funny. I had put in a lipo. I've seen others do it with success. I changed back to OEM battery and cleared up my problem.
When I called Horizon they indicated that using a lipo would void my warranty.

celticflyer 04-05-2011 06:33 AM


Originally Posted by kyleservicetech (Post 798664)
Interesting question.

Pure speculation here. IF (And a BIG IF) the Spektrum transmitters use a linear voltage regulator in their circuitry, and IF that regulator gets to hot as a result of to high of a battery voltage from a Lipo battery, results could be interesting.

Radio loss for 10 and 25 seconds sure sounds like perhaps some voltage regulator either in the transmitter, or the voltage regulator in the ESC got to hot, and shut down to protect itself.

Anybody out there familiar with the power supply circuitry of the DX7 transmitters ????

I'm not familiar with the circuitry, but had a bench problem. My programing started acting funny. I had put in a lipo. I've seen others do it with success. I changed back to OEM battery and cleared up my problem.
When I called Horizon they indicated that using a lipo would void my warranty. I have about 250 flights since, no problems.

kyleservicetech 04-05-2011 06:57 AM


Originally Posted by celticflyer (Post 798669)
I'm not familiar with the circuitry, but had a bench problem. My programing started acting funny. I had put in a lipo. I've seen others do it with success. I changed back to OEM battery and cleared up my problem.
When I called Horizon they indicated that using a lipo would void my warranty. I have about 250 flights since, no problems.

My background is testing, repairing and teaching our customers about testing and repair of the electronic controls for the high voltage circuit breakers the company I worked for manufactured. Those classes took 5 days, at 8 hours/day. The price on these controls start at about $5000.00. That job took me to just about every state in the USA, and 29 foreign countries in the 44 years I worked there.

One thing you learn very quickly on this stuff, is the absolute maximum voltage rating of the very many transistors, integrated circuits, capacitors and the like used in electronic equipment.

You exceed that absolute maximum voltage rating, even briefly like a few microseconds, at your own risk. Typical example, most microcontrollers have a voltage rating of 5.0 Volts DC. (Some newer units operate at 3.6 Volts DC) And those IC's rated at 5 volts might have an absolute maximum voltage rating of 6.5 VDC or so. If that maximum voltage rating is exceeded, some of those Integrated Circuits start drawing more current. A LOT more current, that can result in failure in seconds.

Same on capacitors. Many tantalum capacitors are used in electronic equipment, again with absolute maximum ratings. Exceed that voltage, even once, and that capacitor is likely to fail. Months later. Nature of the beast. (This little item cost our company several different $100,000 recalls over the years.)

So, not knowing exactly what the maximum voltage ratings are on the components inside your transmitter, receiver or servos, regardless of what brand they are, makes me very nervous putting in batteries whose voltage is higher than the voltage of the standard battery used in that equipment.

Yes we had our share of customers who accidentally connected 32 VDC or 48 VDC to a 24 Volt control, or 125 VDC to a 48 Volt control. And, I spent a lot of time fixing the damage to these controls.

Add to this, the effect of ambient temperature and its effect on all of this. Most but not all electronic components have temperature ratings of over 200 F. But some low cost imported counterfeit units might not have the higher quality higher temperature range parts.

Company I worked for certified its equipment to be within specifications from minus 40F to plus 140F, from zero to 100% humidity. Extreme, but that's why they cost in excess of $5000 each.
And, 140F is not really that hot, when you leave your transmitter or receiver in the hot sun for a few hours.

celticflyer 04-05-2011 12:38 PM

Denis V Thank you for your input. You made my point and explained why the warranty would be revoked. I hope everyone is paying attention.

jasmine2501 04-05-2011 05:49 PM


Originally Posted by ministeve2003 (Post 798663)
yup, it's easy once you get the hang of it... at least it doesn't have a cheap @@@ scroll wheel that breaks when you look at it...LOL

SK

Yup, those of us who've been around a while know the evils of scroll bars - I hate them. Touch screens are worse. The DX7 is a solid radio, with no BS - there's a reason for everything.


Originally Posted by kyleservicetech (Post 798664)
Interesting question.

Pure speculation here. IF (And a BIG IF) the Spektrum transmitters use a linear voltage regulator in their circuitry, and IF that regulator gets to hot as a result of to high of a battery voltage from a Lipo battery, results could be interesting.

Yes exactly - plugging a Lipo will cause a number of problems. You need to use a 3-cell LiFePO, which stabilizes at about 10V and runs for weeks like that, and doesn't over-power the DX7.


Originally Posted by celticflyer (Post 798721)
Denis V Thank you for your input. You made my point and explained why the warranty would be revoked. I hope everyone is paying attention.

Yes I agree - if you plugged a wrong battery, even for a second, you voided the warranty.

Saddlebum 04-05-2011 06:03 PM

I fail to see the need to screw around with the stock battery, anyway. My Dx7 can run all day long (and I mean 8 hours of flying) without a recharge. Who needs more than that?

...The Bum


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