Indications Relevant To The Range - Conrad 40MHz Bedienungsanleitung

9. Notes on the range
Ranges and disturbances
• The product works in the 40MHz range which is also used by other products. This is why
there may be a restrictive operation and range due to devices that work on the same or a
neighbouring frequency.
• The range for direct visual contact of transmitter and receiver (the so-called "free field
range") is a maximum of 250 m. It is greatly reduced in buildings (theoretically) depending
on the construction and environment conditions.
Ferroconcrete, metal doors or the use of metal-coated heat insulation can have a negative
effect on the range. The range becomes shorter.
As a rule, when operated in, for example, a family home, faultless operattion should be
possible.
Other causes for a reduced range:
• High frequency faults of all kind (e.g. microwave ovens)
• Any kind of construction and vegetation
• Conductive metal parts which are located near the units or within or near their transmission
path, e.g. heaters, metallized insulation glass windows, reinforced concrete ceilings etc.
• There is an influence on the radiation pattern of antennas due by the distance from
transmitter or receiver to conductive surfaces or objects (metal tables, but also human
bodies or floors)
• broadband disturbances in urban areas which reduce the signal noise distance; the signal
is no longer recognised in these "noises".
• Interference radiation resulting from insufficiently shielded electronics, e.g. turned on
computers or the like.
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