Cleaning; Ranges And Interference, Repeater - Conrad FS20 UTS Bedienungsanleitung

14. Cleaning

Cleaning is only really necessary when you wish to open the device housing, in order to change
batteries or to re-program the "FS20 UTS".
Only use a clean, soft cloth for cleaning. For more stubborn dirt, you can moisten the cloth
slightly with lukewarm water.
Do not use cleaning agents containing solvents, as these may damage the plastic housing and
labelling.

15. Ranges and Interference, Repeater

• The FS20 system works in the 868 MHz range which is also used by other radio services.
Therefore restrictions in the operation and the range can occur through the devices which
work on the same or neighbouring frequency.
• The specified range of up to 100 m is the so-called free field range, i.e. the range within visible
contact between transmitter and receiver. In practical operation, however, there are walls,
ceilings etc. between the transmitter and the receiver which reduce the range correspondingly.
A so-called repeater is available for range extension in the FS20 system.
Further causes for reduced range:
• High frequency disturbances of all types
• Buildings of all types and vegetation
• Conductive metals which are located in the proximity of the devices or within or close to the
transmission path, e.g. radiators, metallised insulation glass windows, reinforced concrete
floors etc.
• Influence on the quality of radiation of the aerials caused by the proximity of the transmitter
or the receiver to conductive faces or objects (also to the human body or the floor)
• Broadband disturbances in urban areas which reduce the signal noise distance; the signal
is no longer recognised in these "noises".
• Irradiation of insufficiently shielded electronic devices, e.g. computers operated openly
59