Lectrosonics R400 - Manual (Page 12)

R400
ANTENNA USE AND PLACEMENT
The receiver is supplied with two right angle BNC
antennas. In some circumstances remote antennas
such as the SNA600 or ALP700 may be useful for
improving reception. Position remote antennas at least
three or four feet apart and not within three or four 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 is a “dropout.”
A dropout can sound like audible noise (hiss or swish­
ing), or in severe cases, it may result in a complete loss
of both the carrier and the 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 a 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 one of the remote antennas
at least three or four feet from its current location. This
may alleviate the dropout problem at that location. If
dropouts are still a problem, try moving the antennas to
an entirely different location.
If the antennas are attached directly to the receiver, try
moving the receiver at least three to four feet from its
current location. If dropouts are still a problem, try
moving the receiver closer to the transmitter.
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
12