Sennheiser Digital 1000 Notice D'emploi page 13

Inserting the battery
Open the battery compartment and insert the battery, taking care to observe
the correct polarity.
Please use type 9 V PP3 (IEC 6 LR 61) alkaline batteries. They ensure
IEC 6 LR 61
an operating time of approx. 4 hours (value depending on battery
type).
N.B.: Using NiCd rechargeable batteries is unadvisable as this would
reduce operating time to under two hours (technical data are not
affected).
Switching on the handheld transmitter
Switch on the SKM 1091 DIGITAL handheld transmitter by setting the
ON/OFF switch
After a short time, the red LED
indicating that the handheld transmitter is now ready for operation.
Selecting a transmission channel
Use the rotary switch at the side of the handheld transmitter to choose one
of the 4 possible transmission channels. The corresponding transmission
frequencies are listed on a sticker in the battery compartment.
Transmitter and receiver must operate on the same channel!
to ON.
below the ON/OFF switch will light up,
13