Shortymet55,
The manual for this RTF package is available online, so you can read through it yourself. You can find the manual here; [link]http://www.hangar-9.com/ProdInfo/Files/han2600-manual.pdf[/link]

But to answer your question. The receiver that comes with this package is the [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=JSP30600]JR RS600[/link] , 6 channel receiver. This means there are 6 "slots" in the receiver. You will only need 4 of those for the servos in this trainer (1 aileron servo, 1 rudder servo, 1 elevator servo, and 1 throttle servo), plus 1 for the battery connection for a total of 5. This leaves one empty channel/slot in which you can plug your VoltWatch in to. So you will not need a Y-harness

Hope this helps

Ken