User’s Guide – 900MHz Stereo Audio Transmitter & Receiver
1
900 MHz Stereo Audio Transmitter
Model AT900 Series
900 MHz Stereo Audio Receiver
Model
AR900-32
Introduction / Product Descriptions
The Model AT900 Series transmitters from Applied Wireless Inc.
are high quality transmitters designed to broadcast excellent
quality low noise stereo audio from any line level source, to the
Applied Wireless model AR900-32 (or PAR900) receivers. The
AT900-32 transmitter is compatible with line level audio sources
such as CD and DVD players, commercial radio (AM or FM)
receivers, satellite radio receivers, MP3 players, ipods and PCs.
These products conform to FCC Part 15 requirements for
unlicensed use, and will transmit over distances up to 750 feet.*
The range may be increased through the use of a directional
antenna (such as a flat panel or Yagi) at the receiver.
* Unobstructed, straight line-of-sight range, when used with the standard
antennas included with the transmitter and receiver.
The AT900-32 transmitter and the AR900-32 receiver provide
thirty-two user-selectable channels of operation within the 902 –
928 MHz band to enable simultaneous operation of multiple
transmitters in a common area. Excellent frequency stability is
assured through the use of crystal references. The products
incorporate precise FM modulation and sophisticated filters to
provide stable, interference-free high fidelity audio reception.
The transmitter and receiver are housed in small yet rugged
aluminum extrusion enclosures. AC power converters (9VDC) are
supplied, along with RCA phono-type audio cables. Depending on
model, the transmitter’s quarter-wave antenna is either
permanently attached (AT900-32) or is remote (AT900-32D). The
antenna supplied with the receiver is a removable quarter-wave
ground plane (sometimes referred to as a half-wave) antenna. The
receiver’s antenna attaches with a
2
Applied Wireless, Inc.
BNC connector, enabling the use of an alternative antenna, (such
as a directional flat panel or Yagi) to increase operating range
(please contact Applied Wireless for a selection of available
antennas).
The AT900-32 transmitter and the AR900-32 receiver are well-
suited for many diverse applications, including distribution of
audio entertainment content throughout a building, PA systems,
commercial and industrial surveillance, monitoring, security, etc.
Installation Instructions
Before Beginning the Installation
Plan your installation carefully. The physical location and
orientation of the transmitter and receiver antennas (relative to
each other and their surroundings) will have a significant influence
on reception quality at the receiver. The following guidelines will
generally yield the best results:
Both the transmitter antenna and the receiver antenna should be
positioned vertically (pointing either up or down).
Antennas should be positioned high enough to enable people to
move about below them without creating obstructions between
the antennas.
Although the RF signal from the transmitter will pass through
most non-metallic building materials (wood, brick, etc.), its
strength is reduced with every wall through which it must pass.
Therefore,
maximum stated reception range is based on
unobstructed line of sight conditions.
The AT900-32 and AT900-32DY transmitters and the AR900-
32 receiver are rated for indoor use only. If either unit must be
located outdoors, it must be protected from the elements
(using, for example, a non-metallic NEMA4 enclosure). The
model
AT900-32DZ
does have
an outdoor rated antenna.
Connecting Audio to the AT900-32 Transmitter
Connect a line level stereo audio source (outputs from a CD player,
for example) to the corresponding
LEFT
and
RIGHT
line-level input
jacks on the transmitter’s rear panel (refer to Figure 1). A shielded
