RE: Dual 2.4 Ghz Futaba Receivers
You could run two receivers off one PowerExpander, I have seen it done but we do not encourage it. The reason is this, the two receivers get electrically connected through the power and ground wires. If one recevier were to have problems that caused noise to go out the power or ground wires it would go directly into the other receiver, possible causing it to have problems. Now, the issue of "Y" leads. Are you saying you want to connect channel 1 to both receivers? This is a really bad idea. If one receiver were to fail its output on the channel may be the last position seen. The other receiver, it good, would try to put the right position on the output. Electrically connecting these together would cause the servo to go nuts. I really, really hope this is not what you are proposing. If it is, I highly recommend you abandon this approach.
1) The power for the receiver can support 1 amp, this should be plenty for 2 receivers.
2) I would not worry about Toroids on the long leads to the second receiver. I would worry about the power leads.
3) Absolutely not, see above.