Bob Mitchell

One of the officers in our club broadcast this email to all members, and I thought I'd post it here. The problem involves loss of receiver bind when using a transmitter tray. I don't use the DX7 myself, so I can't comment on it directly. I've replaced names with "xxxxxxxx".

For what it's worth, here's what they've seen happening.

Bob

++++++++++++++++++++++++++++++++++++++++
9-11-08
>
> Spektrum looses binding.
>
> Yesterday xxxxxxxxxx mentioned to me that his DX7 would
> loose binding and
> he thought he knew why. He also said xxxxxxxxxxx had had
> the same problem.
> Never having this problem, I ask how he thought it was
> happening. He explained
> that his transmitter stand, which is attached to the
> carrying handle of the
> transmitter, would press on the button on the back of the
> transmitter. This
> button is pressed before power on for a binding operation
> and after power on
> for range checking.
>
> After discussing this situation with xxxxx for a while, I
> said I did not know
> why the receiver would loose bind if the binding plug was
> not in the
> receiver. I also qualified my discussion with after having
> been in the software
> business for eons (specifically micro computers), I also
> knew to never to say
> never.
>
> When I got home, I proceeded to do some testing and I will
> say that xxxxxxx and
> xxxxxx are correct. I was using my DX7 transmitter and
> AR7000 receiver. I found
> that if the transmitter bind button is depressed at power
> on something in
> the transmitter changes and it will not communicate with
> that receiver again
> until it is rebound! Note; the receiver does not have to
> even be on while the
> transmitter is put in the bind mode.
>
> After I caused this to happen many times, I proceeded to
> test the DM8
> transmitter module I have been using in other
> transmitters. The DM8 will not fail
> at all. Now with this little bit of knowledge, I tried to
> think how this could
> be. The DM8 module does not have the model match feature
> that the DX7 does.
> The model match feature must modify the GUID that is used
> during the bind
> process. I also thought, assumed apparently wrong, that
> the model match feature
> simply modified the GUID by the model number 1 to N that
> was selected in the
> transmitter and this number would always be the same for
> that model.
> Apparently, some random value is selected at the bind
> operation and that number is
> stored in the transmitter and receiver. If this assumption
> is correct, this
> would explain why the system looses bind when the bind
> button is depressed at
> power on of the transmitter by its self.
>
> I looked carefully at my DX7 and the bind/range check
> button on the
> transmitter back sticks out the back in such a way that it
> could be accidentally
> pressed by a tray device if the handle sticks over the top
> of the tray. This
> could cause two problems. One is the binding problem
> stated above. More
> importantly, if this button is pressed during flight you
> would be transmitting at
> range check power which could cause a loss of a plane.
++++++++++++++++++++++++++++++++++++++++++++++

goirish

WOW!!! That is some good information. I do have the DX-7 and was getting ready to install it for the first time in my Tiger 60. I think I will be very careful (I Hope).

joco1

this same thing happened to me ,but luckily i did it on the ride home in the truck and figured it out when i got home putting after run oil in !!!

bruce88123

This issue has actually been discussed many times in the radio forums.