RE: E-Flite 60-120 Electrict Retracts, Problem
A fully charged 6V pack should probably produce around 6.3V under "normal" load, which is proably between .3 and .5 amps. So it sounds like your the rest of your receiver/servo system is operating normally. My concern is that it probably takes a fair amount of amp draw to pull a healthy 6V pack down to 4.8V. Which is exactly what it sounds like your retracts are doing: the farther they get from vertical, the more torque is being put on the retract motor, so it starts trying to draw more amps, which drops the pack voltage.
To really tell what's going on, you need to use an ammeter/wattmeter to measure the the amps being drawn. If you know any electric flyers, they probably have something like a WattsUp, and may have the necessary jumpers/connectors to plug the meter between your battery and the receiver. The you could go back to H9 and ask how much current these electric retracts are expected to draw.
Part of the problem may be the wiring involved. Standard servo wires are 22-gauge, which is fine for .25-.5amp loads, which is what a normally operating servo will draw. But if the retracts are trying to pull current in the 2-3amp range, there may not be enough cross-section in the wires to deliver that much current.