Lectrosonics UT195 - Manual (Page 7)

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
perpendicular 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” between 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 transmit­
ter or receiver is operated in a different location.
The UR195 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 insignifi­
cant level. If, however, you do encounter drop-outs frequently, call
the factory or consult your dealer. There is probably a simple
solution.
REFLECTIVE SURFACE
DIREC
T SIGN
AL
IND
IRE
CT
SIG
NA
L
DIRECT SIGNAL
INDIRECT SIGNAL
TRANSMITTER
RECEIVER
PHASE
CANCELLATION
MULTI-PATH DROPOUT
Figure 4 - Drop-outs
Rio Rancho, NM – USA 7