Chapter 5_______________________________________Zaxcom Digital Wireless System User’s Manual
52
Powering the Receiver
An external 12 VDC source can be used to power the receiver. This power source can range from 9 to 18 VDC.
However, if the voltage drops below 10 VDC, the audio quality will degrade.
Receiver Connections
This section describes the physical connectors on the receiver.
Audio Output Connector
The XLR-3M connector provides the receiver’s output. Each receiver has two, one for each channel, and they
output at line-level (+4 dBm). There is 20 dB of system headroom.
Pin
Function
1
Ground
2
3
Signal –
Table 5-3 RX4900 Receiver Audio Pin-outs
Antenna Connectors
The rear of each receiver has two BNC connectors, intended to connect to external 50 ohm log-periodic (“Shark-
fin”) or whip antennas. For best performance, keep any transmitters at least 3 feet (1 meter) from the antennas.
This is because strong radio frequency sources reduce the receiver’s sensitivity. The receiver is optimized for
properly tuned external log-periodic antennas. When whip antennas are used, there is a noticeable reduction in
the receiver’s range. You should periodically check that the connector is still securely tightened.
RS-485 Connectors
This connector is used by ZedAlpha to monitor the transmitter and receiver status.
Pin
Function
1
+ RS485
2
- RS485
3
GND
4
N/C
5
N/C
6
N/C
7
N/C
8
N/C
Table 5-4 RX4900 RS-485 Pin-outs (RJ-45)
