Servo chatter in the radio box - Is this normal?

Good Evening. After using conventional radios for most of my time in
the hobby, I thought I'd give a computer radio a try. I purchased a
Futaba 7CAF FM radio, with a T7CAF transmitter, an R127DF receiver, and
4 S3004 servos. I charged up the transmitter and receiver batteries for
15 hours, as the manual suggests, then, without removing anything from
the box, I hooked up the battery to the receiver through the switch.
When I turned the transmitter and receiver switches on, the first thing
I noticed was chattering of the servos. This seemed to worsen as I
walked further away, with the transmitter, from the radio box. Has
anyone else encountered this problem? Will the chatter problem go away
if I unfold the receiver antenna? I am leery of using this system in a
plane until I can get the chatter problem resolved. Any advice would be
appreciated.
Thanks,
Harry Sanchez
snipped-for-privacy@jetlink.net