Is the JR 1221X Rx compatiable with the Smart-Fly Power Expander EQ-10?

Yes it is, However never insert any EQ10 leads into batt or bind ports on rx ,NEVER, read the directions carefully ! Two leads on the EQ10 supply power to the rx bus via the servo ports only, usaually channels 1 & 10, but any two channels will work. RutnBuc

I can see the bind port, why the battery port? That doesn't make any sense.

It creates a back feed situation. Power port not isolated from other outputs.

That's how I understand it.

The power bus is common across all servo ports, the bind port, and the battery port.

The only real difference is each port has a signal line that goes to the decoder to tell that channel's servo where to go. On the bind port that signal line, when shorted to ground, puts the reciever in bind mode. I've seen a couple of BEC's that would put enough bias on the signal line on the bind port to throw the RX into bind mode. Other than that, there's no difference in the power bus.

We just make this a general rule. Battery ports tend to carry special functions and we do not want to interfere with any special function. Since we have a pulldown resistor on all our receiver connections this can cause the receiver to unbind if plugged into the bind port. Also, if you plug any of the receiver leads into anything other than a servo port you loose a channel of the Eq10. Since you are using a 12-channel receiver I would imagine you want to use all 10 channels of the Eq10?

Originally Posted by BarracudaHockey

I can see the bind port, why the battery port? That doesn't make any sense.

As I suspected. Thanks for the clarification.

I was helping someone at an event and he bought an EQ10 from Chief to solve his issue. I had the EQ10 figured out in about 10 minutes and the problem that we spent 3 hours messing with at the field solved in short order.

Good stuff.

Thanks, now I have a new understanding!