VTech SN6187 Abridged manual - Manual (Page 106)

Appendix
99
Operating range
This cordless telephone operates with the maximum power
allowed by the Federal Communications Commission (FCC).
Even so, this handset/pendant and telephone base can
communicate over only a certain distance - which can vary
with the locations of the telephone base and handset, the
weather, and the layout of your home or office.
When the handset is out of range, the handset displays
Out of range OR Base no power.
If there is a call while the handset is out of range, it may not
ring, or if it does ring, the call may not connect well when you
press . Move closer to the telephone base, then press
to answer the call.
If the handset moves out of range during a telephone
conversation, there may be interference. To improve
reception, move closer to the telephone base.
ECO mode
This power conserving technology reduces power
consumption for optimal battery performance. The ECO mode
activates automatically whenever the handset is synchronized
with the telephone base.