quote:

ORIGINAL: do335a

I have yet to see an electronic device which is not subject to either total or intermitent failure.

How can you guys say that it is impossible for a TX to fail?

Even computers in manned spacecraft have failed. So have electronic instruments and ignitions in automobiles, computer hard drives, TVs, stero systems, electronic cameras and whatever other electronic device you care to pick, except the radio control aircraft transmitter according to what I've read here. What makes it so special that it's immune to failure?

quote:

ORIGINAL: do335a

I have yet to see an electronic device which is not subject to either total or intermitent failure.

How can you guys say that it is impossible for a TX to fail?

Even computers in manned spacecraft have failed. So have electronic instruments and ignitions in automobiles, computer hard drives, TVs, stero systems, electronic cameras and whatever other electronic device you care to pick, except the radio control aircraft transmitter according to what I've read here. What makes it so special that it's immune to failure?

quote:

ORIGINAL: stoneenforcer


9020 pins/connectors are the same as every other spektrum rx in my shop. I clearly posted the admitted issue with these, from horizon.

reversing polarity will burn the rx up.

We have been getting shafted for far too long when it comes to 2.4GHz radio systems.

Now millions are using the 2.4GHz unlicensed band everywhere and there is more to come.

When the band is saturated error occurs, the industry calls it "BROWNOUT" and cleverly blames it
on the battery pack!

It is too bad that we can not reboot a crashed model airplane.

quote:

ORIGINAL: fragile

We have been getting shafted for far too long when it comes to 2.4GHz radio systems.

Now millions are using the 2.4GHz unlicensed band everywhere and there is more to come.

When the band is saturated error occurs, the industry calls it ''BROWNOUT'' and cleverly blames it
on the battery pack!

It is too bad that we can not reboot a crashed model airplane.

quote:

ORIGINAL: P47Tbolt

I have found from doing some voltage testing from the battery pack to any receiver,you will have a certain
amount of voltage drop due to connections and switches.I just setup a Wild hare Edge 540 50cc using Power HD 1501mg servos,DX8 and an AR8000 receiver with telemetry.
Battery is a Hobbico Life 6.6v 2100 with 2 switches.One switch is a JR chargeswitch(JRPA004),the other is a switch I bought from
the Perry r/c swapmeet for $10.00 that looks like a JR chargeswitch but is not.with the telemetry I can see what voltage is at the receiver from the DX8.It records min and max voltage automatically on screen.With just the $10.00 switch on my voltage was dropping to 3.9v from 6.6 while operating all servos.With just the JR switch on the voltage would drop to 5.6v from 6.6 while operating servos.with both switches on it would drop to 5.9v from 6.6 while operating servos.
voltage drop is servo load and from resistance in cheap switch,you also have some resistance in all the connections between receiver and battery.keep connections to a minimum.Also use HD servo extensions with gold plated terminals for a very good connection.
And try not to plug/unplug connections often.each time you plug/unplug,it expands the female side and eventually it will loose its tension.
With a 4.8v pack with a bad connection or cheap switch it will be enough to make the receiver reboot/brownout whatever you want to call it. With a 6.0v pack with loose/dirty/ connections or a cheap switch it still can drop enough voltage also.

I have setup all my planes that are on Spektrum using this way and never seen a problem,
by checking to see what voltage is at the receiver,I know what is there.You can not put a 6.0v pack on a system
and hope you get 6.0v there.you make sure you get the voltage there by testing it with a voltmeter at the receiver.
People just hook everything up and say its got a 6.0v battery,should be good. May have 6.0v at battery,but by the time it gets to the receiver,it will be less.You just need to take the time and make sure you are getting as much as that 6.0v from the battery to the receiver while under load(moving servos) as possible through by CHECKING VOLTAGE AT THE RECEIVER NOT THE CHARGE JACK OR BATTERY.

As far as my credentials on this,
no I am not an electrical engineer
but

I am a GM Mastertech
ASE Mastertech
specialize in
Electrical repairs
I am constantly looking at problems on GM products
pertaining to voltages/voltage drop within the GM high speed
and low speed communications between computer modules.

quote:

ORIGINAL: sidgates

I have read all 5 pages of this forum and I don't think anyone has mentioned that testing voltage with an analog or digital meter is NOT going to catch a very fast "brownout" that can occur in the power supply system whether you are using 4.8 volts supply or 6.00volt supply.

Somebody did mention that some receivers will catch the problem and display it on an LED. Very short brownouts can reboot the receiver even though your volt meter does not see the problem.

Another gadget is sold called the "Tattletale" which captures the lowest voltage reading every 10ms until it is reset. I use one in all new installations for awhile and plug it in any questionable battery.

I built hobby radios for 15 years (1968-1983) and one time received a call and was told by the customer that his elevator servo had reversed itself in the air (before reversing switches). I told him it wasn't possible but send me the radio. He sent the radio and he was right. The magnet in the servo motor had loosened and rotated 180 degrees under vibration. I never told anyone after that a malfunction was IMPOSSBLE.

quote:

ORIGINAL: sidgates
...
Another gadget is sold called the "Tattletale" which captures the lowest voltage reading every 10ms until it is reset. I use one in all new installations for awhile and plug it in any questionable battery.
...

I found something interesting in the DX8 manual,

“CAUTION: When using the DX8 with parkflyer receivers (the

AR6100 and AR6110), it’s imperative that these receivers only be flown

in parkflyer-type aircraft (small electric airplanes or mini and micro

helicopters). Flying receivers designed for parkflyers in larger aircraft

could cause loss of connection.”

Between this and the extensive instructions on power requirements for receivers I think backs up the theory

that the problems are not the DX8 but more in the receiver power. I recently purchased a new DX8 and love it. I am not loyal to any manufacturer and this can be proven in my driveway. I have Chevy, Ford, and Honda. Everything I have is linked to Spektrum so rather than change everything to another brand I bought the DX8 to replace my DX7. I did read all of this thread before my purchase. As far as recalls they all have them but the nice thing with the DX8 is the fact that you can download programming upgrades and load the yourself instead of sending it to the factory. If you use Windows this is not an unusual process. Recently I reloaded Vista to an old laptop I had and found close to 200 updates for it on the Windows site. Now all of them are not repairs for bugs. A lot of them are improvements on the original program. This upgrade online, is one of the things I like about the DX8. I just thought I would throw in my 2 cents.

Rick

quote:

ORIGINAL: acdii

I had lost control of my Eflite T-34, at first I thought it was just a fluke of the wind, but after having it happen on another day with calm winds, I realized what the problem was, not the wind, but an actual loss of control.  After a couple more glitches I finally was able to bring it down, and not so nicely either, busted the firewall, cracked the center wing ribs, and munched the cowl.  Before I did anything, I popped off the canopy and saw the orange LEDs blinking.  

I first assumed it was a brownout from the DX8, reading that older RX had problems with the new DX8, but my radio did not fall in the range of codes with the problem.  After some research, here on the forum, and talking to HH, it was a brownout, not a link failure. The link failures have a red blinking light that flashes for every dropped link. 

I have since scrapped the motor and ESC and putting glow and a 5 cell 1600 mah pack in it, and will soon have it flying again.   I also use a pack tester on the batteries before every flight, one that puts a small load on the pack and reads back battery state so I will never have another brownout as long as I check before each flight. 

As far as the DX8 goes, I'm confident the problem was not the radio.  Right now I have 3 planes on the DX8 that I fly, and none of them ever had a red blinking light that I didn't cause by turning the TX off.   I didn't bother reading through all 5 pages, but has the OP specified he actually saw the red blinking light at any time that he didn't cause by switching off the TX? 

quote:

ORIGINAL: rickmartin2010

I found something interesting in the DX8 manual,

“CAUTION: When using the DX8 with parkflyer receivers (the

AR6100 and AR6110), it’s imperative that these receivers only be flown

in parkflyer-type aircraft (small electric airplanes or mini and micro

helicopters). Flying receivers designed for parkflyers in larger aircraft

could cause loss of connection.”

 

Between this and the extensive instructions on power requirements for receivers I think backs up the theory

that the problems are not the DX8 but more in the receiver power.......