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cptsnoopy
07-14-2010, 03:47 PM
I pm'd Art about this a couple of days ago but while I wait for a reply I wonder if anyone else has had the dreaded no rx input error (radio reception if looking at the flight log replay) while flying. I had it happen two flights in a row after lift off and during the first maneuver. Both times the the heli went into failsafe and then recovered just a second later. Both times I did not crash but immediately landed the heli and shut it down. I have flight logs of those two flights and also of pretty much every other flight on this thing. These flights were after at least 14, 5 minute flights with no problems at all. I wonder if it is from high heat, static or some other reason? Looking at the flight logs, there is no appreciable dip in voltage, it looks like it is holding fine between 5.5 and 5.8 volts.

I am using two Spektrum satellite receivers and my DX-7. I took the blades off and tested it in the house with the motor spooled up but I could not duplicate the problem.

Any ideas?

Charlie
:)

cptsnoopy
07-16-2010, 10:21 PM
Here is a copy of an email I sent to Art a couple of minutes ago. I don't know if changing the satellite receiver really had anything to do with my problems but I was able to get a full 5 minute flight in today with no resets or other strange issues. :banana

I am happy to report that I may have found the issue but I won’t really know for sure until I have more uneventful flights. This is what I found: When I unplugged one of the Spektrum satellites and then plugged it back in all worked fine, the orange led on the satellites started blinking as they should and the SK720 status led stayed green. When I unplugged the other Spektrum satellite the system was ok until I plugged it back in, then the status light on the SK720 would turn red and it would re-initialize with a pitch pump and a green status led when it was ready (provided the heli nor the tx sticks were moved while this was going on. The only thing different between what was happening in flight vs this testing is that the orange led’s on the satellites would still be solid orange when I landed and the SK720 status led would be flashing red. (because I was moving the tx sticks and the heli was airborne while it was resetting.) This causing of the SK720 to reset was not totally consistent, it would reset approx every 7 out of 10 disconnect/reconnect cycles. Since the first satellite did not cause this resetting I decided to try another Spektrum satellite in its place and see how it did. As it turns out the next satellite did much better only causing a reset approx 1 out of 20 tries. I was hopeful given the improvement and I installed the new satellite receiver in place of the troublesome one. Then I redid the tail box to boom ground and added the large ground wire from the power-buss to the frame ground to help improve static discharge through the system. I flew it again today in fairly windy conditions and it seemed to do fine. I have attached that flight log to this email and if you are interested you are welcome to look at it. The only thing was the same for today’s flight was the outside temp of approximately 105f. Hopefully this was the problem and I can see about sending this satellite back to horizon to see if they can find out why it was “spiking” the system into a reset.

georgi UK
07-17-2010, 01:17 PM
=] this should help you >

NOTE: The setup software will display the error state that caused the LED to
flash red. Errors are displayed on a magenta background in the Live Data area.
Connect the gyro to the setup software using the USB cable to find the specific
type of error. Error states are also recorded in the log file and will be displayed by
the playback software. Resetting the gyro will clear the error message

ESD issues > if you landed with controls, means you are getting into lottery winner territory!!!

georgi UK

cptsnoopy
07-17-2010, 11:13 PM
=] this should help you >

NOTE: The setup software will display the error state that caused the LED to
flash red. Errors are displayed on a magenta background in the Live Data area.
Connect the gyro to the setup software using the USB cable to find the specific
type of error. Error states are also recorded in the log file and will be displayed by
the playback software. Resetting the gyro will clear the error message

ESD issues > if you landed with controls, means you are getting into lottery winner territory!!!

georgi UK

Yes, I got lucky twice. I then decided not to fly it again until I could figure it out. Sadly I did not take a screen shot of the error message when I hooked up the computer but I believe it was "no rx input". The flight logs say something similar but different. "receiver reception".

Since I changed the questionable Spektrum satellite receiver, I have now had two full 5 minute flights with no reset or loss of control. I will be sending in the bad satellite to see if Horizon can figure out why it would cause a reset to the SK720.

I had a great flight this morning and am hoping the good luck continues.

Charlie
:)

adelmasw
07-18-2010, 07:43 AM
This is an argument for flying with two satellite receivers... I had one receiver that turned off during a flight and figured out it was the connector ON the Rx, not the wire. I sent it back to Horizon and they replaced the receiver. Their service is wonderful.

cptsnoopy
07-18-2010, 06:25 PM
This is an argument for flying with two satellite receivers... I had one receiver that turned off during a flight and figured out it was the connector ON the Rx, not the wire. I sent it back to Horizon and they replaced the receiver. Their service is wonderful.

I would agree and I have been using 2 satellite receivers since I installed the SK720. My issue was not with the wires either. Maybe something about the plug on that one satellite was causing a spike (or short) when plugging the wire in (and somehow during flight), I don't know. I do know that when I replaced the one satellite with another, it all works fine again... (so far)

Charlie
:)