Rx binding info needed

[Rolex]

I've been trying to bind an Esky heli to a Spektrum DX7. There's a process to unbind the Rx, and I've done that, yet it will not bind to the DX7. The light on the Rx doesn't indicate that it's ready for binding. However, whether the Rx is in binding mode or receiver mode, turning on the stock radio binds it.
Isn't every 2.4 Radio able to be bound to a 2.4 Rx?
I've had no problem with helis that come in "Bind n' Fly" versions without a radio.

 

[alpinehyperlite]

I know that all 2.4 systems aren't the same. I know on land based vehicles, you can bind losi 2.4 receivers to spectrum 2.4 radios, but not to futaba 2.4 systems.

 

[Rolex]

From what I've read, I shouldn't be having a problem. I also saw that Futaba won't work, but I think it was just the FSST. Either way, I'm not using Futaba on this one or any of my air units.