Losing Bind

[Yak52Driver]

I am using a FrySky XJT Module in my Turnigy 9X with Extreme Board and numerous X8R RXs; twice now with different models I have had the TX/RX combo lose bind from being shutdown one day and turned back on another. Is there a limit to how many RXs can be bound or is this gremlin at work?

[jhsa]

If you remove the XJT module and look at the pins inside the module bay, Is there some plastic surrounding the lower half of the pins? If so, you might need to remove it because it could cause the module to not fully connect to them..

João

[Yak52Driver]

Sorry for the delay in responding, I have just looked at the pins under a magnifier and they are perfectly clean and clear of any coatings. If this had only happened once I would put it down to me having not "bound" the RX properly in the first place, but twice?

[MikeB]

Check this post: viewtopic.php?f=7&t=8741&p=114455&hilit ... ic#p114455. It shows how the pins should look with the extra plastic moulding removed. It isn't a coating on the pins but a large piece of plastic that stops the XJT module fitting properly.

Mike.

[pmshop]

@yak52driver, is it Bind you are losing or Tx/Rx connectivity?

I am developing an issue where during bench testing, occasionally the PixHawk will signal over and over Tx/Rx connection, connection lost and connected again.
This occurred once in flight with the 9Xtreme controller voicing "No Telemetry".
With radio failsafe set to "Continue Mission", all I could do is watch the craft drift into the trees bouncing off of them till a prop got tangled and it came down (20 feet - 6m)

[Yak52Driver]

It is the actual Bind, I have to re-bind the TX/RX and that solves the problem, it occurs on turn on, I have (fortunately) never had it happen once the set has turned on normally. I have got some of the plastic pin mouldings protruding into the module bay as discussed above, so I will remove that and see if it fixes the problem.

[pmshop]

Although the plastic should be removed anyway, I doubt if it is a pin issue.
Once you bind it should remain bound.
That is what gives you the ability to switch between models if you have multiple crafts.

I only chimed in because I have had on 2 occasions so far, total loss of link in flight not more than 20 feet (6m) away.
Second occasion my controller continued to voice cycle "camera on, camera off" for the duration of the lost link until RTL was complete.
My case might be a pinched wire since I modded through SmartieParts.com .

[bob195558]

Hi pmshop,
You may also want to consider the Fresnel Zone, see here for more info: (https://www.youtube.com/watch?v=xCVd3QGQhKU).
I have had this problem with other pilots too, when flying from the bottom of a hill, losing partial stick controls (Rudder and Aileron) because of a Fresnel Zone.
The hill is much higher to our left with trees and much lower to our right no trees.
Aileron stick control worked to the left and no response to the right so we have to stay flying to the right side to maintain full stick controls.
I have also seen (some times) total loss of stick controls (0 to 20 feet) when around metal building, power lines, chain-link fences, cars and communication transmitter antennas.

It is hard to see (discern) what may be the cause for signal failure between your transmitter and receiver.
It can be a bad wire connection, transmitter and/or receiver problem, antenna problem or even a blast from a more powerful communication transmitter raising the noise floor level up blocking your transmitter to receiver signal connection.
Because we can not see how our transmission looks in the environment where we are flying when it suddenly fails, it is difficult to see what has caused the problem.

[Yak52Driver]

Removed the plastic around the module pins, I know that it is not the cause but given as others have said it makes the module go home easier it was worth doing. I am not temporarily losing link, I am losing Bind, the radio simply stops talking to the RX and until you go through the bind process again. It has happened twice now with two different RXs. I will note if it happens again in the future and report back.

[Kilrah]

It's happened to others before when there were power supply problems on the receiver side (voltage falling very low, below 3V or so). Might want to investigate that.