Lectrosonics UCR195 - Manual (Page 10)

ANTENNA USE AND PLACEMENT
Position the antenna so that it is more than 3 or 4 feet
from large metal surfaces. If this is not possible, try to
position the antenna so that it is as far away from the
metal surface as is practical. You can also let the metal
surface work for you by aligning the antenna perpendicu­
lar to the surface. This will provide a ground plane for
the antenna. It is also good to position the receiver and/
or antenna 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 50
feet, the antenna positioning is much less critical.
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
“drop-out.” A drop-out 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 in the room. Moving the
transmitter even a few inches will change the sound of
the hum or hiss, or eliminate it. A drop-out situation
may be either better or worse as a crowd fills and/or
leaves the room, or when the transmitter or receiver is
operated in a different location.
The UCR195 receiver offers a sophisticated front end
design which overcomes drop-out problems in almost
any imaginable situation. At UHF frequencies, drop outs
(noise ups) are often so brief that they sound like a
"click" rather than a burst of noise. Generally, drop outs
are virtually non-existent within several hundred feet of
operating range. In the event, however, that you do
encounter a dropout problem, first try moving the
antenna at least 2 or 3 feet from where it was. This may
alleviate the drop-out problem. If drop-outs are still a
problem, try moving the antenna to an entirely different
location in the room or move the antenna in closer to the
transmitter location.
Lectrosonics transmitters radiate power very efficiently,
and the receivers are very sensitive. This reduces drop­
outs to an insignificant level. If, however, you do
encounter drop-outs frequently, call the factory or
consult your dealer. There is probably a simple solution.
DIRECT SIGNAL
INDIRECT SIGNAL
DIRECT SIGNAL
INDIRECT SIGNAL
MULTI-PATH DROPOUT
TRANSMITTER
RECEIVER
PHASE
CANCELLATION
REFLECTIVE SURFACE
Figure 4 - Drop-outs
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