Antenna use and placement, Reflective surface direct signal indirect signal, Multi-path dropout – Lectrosonics UCR411 User Manual

Page 11

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UHF Wireless Digital Hybrid

TM

Receiver

ANTENNA USE AND PLACEMENT

The receiver is supplied with two straight BNC antennas.
In some circumstances remote antennas such as the
SNA600 or ALP700 may be useful for improving recep­
tion. Position remote antennas at least three or four feet
apart and so that they are also not within 3 or 4 feet of
large metal surfaces. If this is not possible, try to posi­
tion the antennas so that they are as far away from the
metal surface as is practical. It is also good to position
the receiver so that there is a direct “line of sight” be­
tween the transmitter and the receiver antenna. In
situations where the operating range is less than about
100 feet, the antenna positioning is much less critical.
The antennas can also be configured with one whip
mounted directly onto the panel of the receiver, and the
other one mounted remotely.

Be careful about the length of cabling from antenna to
receiver. Long cable runs can have serious signal loss.
Lectrosonics has in-line RF amplifiers suitable for
compensating for long cable runs. Contact your dealer or
the factory for more information.

A wireless transmitter sends a radio signal out in all
directions. This signal will often bounce off nearby walls,
ceilings, etc. and a strong reflection can arrive at the
receiver antenna along with the direct signal. If the
direct and reflected signals are out of phase with each

other a cancellation may occur. The result would be a
“dropout.” A dropout sounds like either audible noise
(hiss), or in severe cases, may result in a complete loss
of the carrier and the sound when the transmitter is
positioned in certain locations. A UHF dropout normally
sounds like a very brief “hiss” or a “swishing” sound.
Moving the transmitter even a few inches will change the
sound of the dropout, or eliminate it. A dropout situation
may be either better or worse as the crowd fills and/or
leaves the room, or when the transmitter or receiver is
operated in a different location.

The receiver offers a sophisticated diversity design which
overcomes dropout problems in almost any situation. In
the event, however, that you do encounter a dropout
problem, first try moving the receiver at least 3 or 4 feet
from where it was. This may alleviate the dropout
problem at that location. If dropouts are still a problem,
try moving the unit to an entirely different location in the
room or moving the receiver in closer to the transmitter
location.

Lectrosonics transmitters radiate power very efficiently,
and the receivers are very sensitive. This reduces
dropouts to an insignificant level. If, however, you do
encounter dropouts frequently, call the factory or consult
your dealer. There is probably a simple solution.

REFLECTIVE SURFACE

DIRECT SIGNAL

INDIRECT SIGNAL

DIRECT SIGNAL

INDIRECT SIGNAL

TRANSMITTER

RECEIVER

PHASE
CANCELLATION

MULTI-PATH DROPOUT

Rio Rancho, NM – USA

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