Diversity Reception - Sennheiser EM 3031-U Manual De Instrucciones

AF-signal AF-signal
receiver 1
electronic switching receiver 2
from one signal to another
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Diversity reception

The EM 3031/3032 receiver operates on the "true diversity" principle:
A receiving antenna receives not only the electromagnetic waves which reach it by a direct path,
but also the reflections of these waves which are created in the room by walls, windows, ceilings
and fittings. When these waves are superimposed, destructive interference occurs, which can also
be called "field strength gaps". Repositioning the receiving antenna can bring a solution, provided
the transmitter remains in its original position. With mobile transmitters, however (which all
radiomicrophones are ), the "field strength gap" will then occur with a different transmitter position.
These "field strength gaps" can only be eliminated with true diversity receivers.
In true diversity, instead of one antenna and one receiver there are now two antennæ and two
receiver sections. The antennæ are spatially separated. By means of a comparison circuit, the
receiver section with the strongest RF signal is always switched to the common AF output. The
risk of the occurrence of "field strength gaps" in both antennæ at the same time is virtually
nonexistant.
The display panel of the receiver always shows whether the diversity channel switched is channel
A or channel B.
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