Lectrosonics R400a - Manual (Page 9)

UHF Wireless Diversity Receiver
Rio Rancho, NM 9
The receiver is supplied with two right angle BNC an-
tennas. In some circumstances remote antennas such
as the SNA600 or ALP600 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 position 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” between
the transmitter and the receiver’s antenna. In situations
where the operating range is less than about 100 feet,
the antenna positioning is much less critical. The an-
tennas can also be configured with one whip connected
to one antenna input of the receiver, and a remote
antenna connected to the other antenna input.
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 di-
rections. This signal will often bounce off nearby walls,
ceilings, etc. and a strong reflection can arrive at the re-
ceiver 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 swishing),
or in severe cases, it may result in a complete loss of
both the carrier and the sound. Moving the receiver’s
antennas even a few inches will change the sound of
the dropout, or often eliminate it. A dropout situation
may also be either better or worse as a crowd fills or
leaves the room, or when the transmitter or receiver is
operated in a different location.
The R400A receiver offers a sophisticated diversity de-
sign which overcomes dropout problems in almost any
situation. In the event, however, that you do encounter
a dropout problem, try moving the receiver or antennas.
If the antennas are attached directly to the receiver,
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.
If remote antennas are used, try moving one or both
of the remote antennas at least three or four feet from
their current location. This may alleviate the dropout
problem at that location. If dropouts are
still a problem, try moving the remote an-
tennas to an entirely different 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.
Antenna Use and Placement
Better
antenna
placement
Good
antenna
placement
Poor antenna
placement
Front mounted whips with
optional rack mount
Optimal antenna placement
with optional remote antennas