Lectrosonics SR175 - Manual (Page 6)

ANTENNA USE AND PLACEMENT
Connect the antenna to the rear panel jack. Extend the antenna fully if you are using a telescoping
type. Position the antenna so that it is not touching or within 3 or 4 feet of large metal surfaces. It is
also good practice to position the receiver so that there is a direct "line of sight" between the transmitter
and the receiver antenna.
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 sound when the transmitter is positioned in certain locations in the
room. A dropout normally sounds like "hum" or "hiss." Moving the transmitter even a few inches will
change the sound of the hum or hiss, or eliminate it. A dropout situation may be either better or worse
as the crowd fills and/or leaves the room.
In the event that you do encounter a dropout problem, first try moving the receiver/antenna at least 3 or
4 feet from where it was. This may alleviate the dropout problem. If dropouts are still a problem, try
moving the receiver and/or the antenna to an entirely different location in the room.
Lectrosonics transmitters radiate more power, and the receivers are more sensitive than any other on
the market. This reduces dropouts to an insignificant level. If, however, you do encounter dropouts
frequently, call the factory. There is probably a simple solution.
REFLECTIVE SURFACE
DIREC
I
TRANSMITTER
PHASE
LECTROSONICS
SR175
RECEIVER
CANCELLATION
MULTI-PATH DROPOUT
5