User's Manual

Digital Hybrid Wireless
®
Modular Receiver System
Rio Rancho, NM, USA
13
Modulation (audio level)
Full modulation (onset of limiting)
Transmitters also have modulation indicators such as
the LEDs on the SM Series models.
Modulation LEDs (audio level)
Signal Level -20 LED -10 LED
Less than -20 dB Off Off
-20 dB to -10 dB Green Off
-10 dB to +0 dB Green Green
+0 dB to +10 dB Red Green
Greater than +10 db Red Red
Full modulation is achieved when the -20 LED first
turns red. The output level of the receiver reaches
maximum at this point, when the limiter in the transmit-
ter begins to operate.
The output level control on the receiver is basically an
attenuator, so the signal to noise ratio changes very
little across the entire adjustment range.
Optimizing the Signal to Noise Ratio
Given the information above, the optimum signal to
noise ratio is achieved when the least amount of gain
is applied to the signal, since gain (amplification) is the
source of noise buildup.
The transmitter input preamp is the low noise gain
stage at the beginning of the signal chain. The ideal
setup is to have this be the only gain stage, and sub-
sequent stages be at unity (zero gain/loss). Attenuation
(loss) in a subsequent stage is OK unless it requires
another gain stage to compensate for it.
1) Set the transmitter gain so that full modulation is
achieved on louder peaks in the audio
2) Set the receiver output level as high as possible
without overloading the connected device it is
feeding (mixer, recorder, etc.). Use a line level
input on the connected device whenever it is
available. This minimizes the gain needed in the
device and maximizes the signal to noise ratio.
Diversity Pairing
Navigate to the DIVERSITY LINK screen in the RX
Menu. Press the encoder to open the setup screen.
Highlight to select
receiver pair
Highlight to set diversity mode
of selected receiver pair
Selected receiver pair
marked by brackets
Select CHOOSE RX on the bottom of the screen and
rotate the encoder to select the desired pair. Highlight
EDIT and rotate the encoder to make the setting.
The receiver icons are arranged so that adjacent units
are paired when the RATIO mode is set. When the
SWITCHED mode is set, the units operate indepen-
dent of one another.