Hey all,

Had an odd crash the other day, plane will survive that went like this.

I have a DX7 and this particular plane has an AR6000 receiver. Plane has a 800mah lipo and 6V MPI regulator. Hitec mini Digitals and a Hitec mini MG on the throttle.

Have flown this plane a lot never any issues. Receiver and radio is about a month old. (just converted it to Spektrum, was 72mhz before)

Plane went full throttle, and I had no control. When picking it up put of the bushes, the plane was acting normally.

Brought it back to the pits, the throttle servo went from full to closed several times, and then after that the plane acted normally and it never failed again (regrettably)

Back at home, I discharged the battery I hadn't charged it since the incident and got 760mah out of it. Checked the regulator (it's one of those small shrink wrapped ones) it holds 6V solid even when pushing 3A and warm. Shook the whole thing around, decided it wasn't a power problem.

Recharged the battery, put it and the reg back in the plane. turned on radio and plane and sat it next to me while doing other work. I'll be darned after 5 mins the light on the receiver turned off, the throttle went full and a few seconds later the light turned back on and the throttle dropped back down.

It's still sitting here next to me and it hasn't failed again in 20 mins.

I am stumped. Bad receiver? Radio? Man I've never heard of anyone having a problem like this with Spektrum.


HELP!

I can only guess, but I would suspect a dodgy rx. Or have you checked the switch? Try swopping for another and try again.

Richard

Should have said, for testing connecting regulator directly to the receiver bypassing the switch.

Too low a voltage in your lipo ? You mentioned you
discharged 760 mAh's out of a 800 mAh lipo. What
was the voltage after Discharging ?

Bob

Should have indicated that as well, it was 6.4V after 760Mah discharge (3.2 per cell).

Again sitting here waiting for it to fail.

Try taking the regulator out ,along with the lipo.
Use a 4.8 or 6.0 volt niCd or nMhi and watch.


Bob

I agree. Doing this will either confirm or rule out a battery/regulator problem. If it still acts up with the Nicad battery, send the transmitter and receiver to Horizon for service. It won't be long before the weather limits available flying days anyhow and you'll feel a lot better knowing that the radio has been checked out and repaired if needed.

Hey guys thanks for the replys,

Tested with a 5 cell nicad, no regulator, no problems.

Back to running it with the lipo and regulator, no problems.

Found out that I set the receiver failsafe to be all control surfaces neutral, but the throttle goes wide open (missed that little detail when I bonded the receiver).

So that would imply, possibly, that it was not power but a loss of signal, since the servos went to their failsafes the receiver still had to have power.

So I'm back to square one, don't know if it was the radio or receiver. If It hadn't failed that one time here at home I would start to think I was shot down at the field.



I'll keep you posted.

Your right about the fail safe, but if your lose of signel lasts that long I would still think there is still a problem.

I had a problem with a rx and jitters, I had the rx too close to the esc and bat. wires.

I have been putting my 2.4 rx's back away from the motors and elect as fare as I can.

The motor or elect can block signel to the ant. on the RX. I am not saying any of this is your problem, just things I do.

good luck

Change your failsafe on you throttle and
watch some more. Try a Bench run.

Bob

You aren't using a 3S pack in your TX, are you? Spektrum has a note up on their site advising against that. Apparently there is an over voltage problem and the voltage regulator overheats.

Also, if you check the specs for the Spektrum RX and servos, I think you'll find they're rated up to 9V. I'm running mine off of 2S lipos and no regulator. Takes one more potential point of failure out of the equation.


Tom

I admit that using a 3C lipo was the problem. Realized after more research that this is a common problem and extensively discussed on the boards- the existing voltage reg on the RF board was overheating and becoming intermittent when using the AR6000 receiver BC the radio bumps up to a higher power output. Electronics is my thing so it was an easy fix to swap out the reg with a dimension engineering 3.3 volt DC-DC converter. Have used the radio a lot since the fix and all is good, best thing is it seems I'll only have to charge my radio a couple times a season. It's multiples more efficient. Started with the lipo at 12.5V, after 4+ hours of use and a couple weeks of sitting around it's at 11.8V.

Beware of using Lipos in Spektrum and JR radios without this mod - Almost all of my flying buddies use lipos in their spektrum and JR radios, I am the only one who ever had problems, maybe they will, maybe not - I wouldn't take a chance.

Sorry didn't read good enough my mistake. Glad you got it fixed.