# 16022699
Page 5 of 8
The scrambler has been added for greater security, and to avoid
listening in by unauthorised persons. It is based on simple frequency-
inversion techniques due to the very low power needed for that sort of
circuit. In the scramble mode, the audio frequency response, as well as
the signal to noise ratio, are somewhat minimized compared to the
unscrambled mode.
Changing channels
: It is possible to shift between 4 channels by the
remote control. The 4 channels (frequencies) are preprogrammed in the
transmitter. During operation, it is possible to shift channel in order to
use the optimal channel (frequency).
1.2.3 Application Note
To achieve maximum RF range it is advisable to keep the antenna as
far away from the surroundings as possible. If an antenna is in close
proximity to metal surfaces, concrete walls or the human body, the
efficiency of the transmitter will be minimized due to power absorption
and disturbance of the antenna radiation pattern.
For maximum battery lifetime and for minimizing the risk of being found
by bug detectors or scanners, the transmitter can be switched off into
sleep-mode by means of the remote control. Alternatively, simply
choose VOX mode, when in doubt whether persons will be present in
the room being monitored. The TX will then only go “on the air” every
time conversation is detected in the room. After app. 15 sec. without
conversation, the TX will go to sleep again and thus sawing battery
power.
1.2.4 Wire connection
