ORIGINAL: dirtbug
Hitec HS-5925MG digital servo ... still using the crummy AM 27Mhz radio ... plugged the new hitec servo into the receiver ... using the standard 4.8 volt AA batteries
Try using a Y-connector (See the instructions that came with the servo. It will show you.) Also make sure you've got a full charge. Last but not least, it's probably best to just wait on the digital servo until the FM radio comes.
Good Luck,
RobH