CIRCUIT DESIGN WA-TX-03S User manual

OG_WA-03S_V10e
OPERATION GUIDE
UHF Wireless Audio Module
WA-TX-03S / WA-RX-03S
Operation Guide
Version 1.0 (July 2017)
CIRCUIT DESIGN, INC.,
7557-1 Hotaka, Azumino-city
Nagano 399-8303 JAPAN
Tel: + [phone]
Fax: + [phone]
e-mail: [e-mail]
http://www.circuitdesign.jp

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OPERATION GUIDE
CONTENTS
GENERAL DESCRIPTION ................................................................3
FEATURES .......................................................................................3
APPLICATION ...................................................................................3
SPECIFICATION ...............................................................................4
TERMINAL DESCRIPTION ...............................................................5
CHANNEL TABLE .............................................................................7
REMARKS FOR INTEGRATION OF THE RECEIVER ANTENNA ....7
CONNECTION DIAGRAM .................................................................8
DIMENSIONS .................................................................................10
REFERENCE DATA.........................................................................12

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OPERATION GUIDE
GENERAL DESCRIPTION
The WA-TX-03S / WA-RX-03S are 15ch multichannel audio modules that operate in
the European harmonized 863 - 865 MHz band. In addition to offering a frequency
range sufficient for voice transmission, the compander noise reduction system has a
wide dynamic range, enabling transmission of clear audio signals.
As embedded devices, they include nearly all the parts necessary for audio
transmission in a small shielding case, making it possible to develop audio
transmission equipment in a short time.
FEATURES
863 – 865 MHz European Audio band
15 channels, 125 kHz steps
90 dB dynamic range with built in noise reduction system
50 Hz - 13 kHz audio response
Low power operation
Adjustable mute level
Small size for embedding in user equipment
RED compliant
RoHS compliant
APPLICATIONS
Audio guiding in museums
Tour guide systems
Wireless conference systems
Wireless microphone systems for amateur users
Various audio transmissions
Voice monitoring

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SPECIFICATION
Common
Items Specification Remarks
Compatible standard EN 301 357 RE Directive
Frequency range 863.125 – 864.875 MHz
Number of channels 15 125 kHz step
Emission class F3E
Operating distance 50 m Line-of-sight
S/N ratio 90 dB or more W/IHF-A Filter
Audio frequency response 50 Hz-13 kHz +/-3.5 dB
T.H.D 2 % @AF 1kHz, Δf = 20kHz
Emphasis 50 us
Operating temperature range 0 to 50 °C
WA-TX-03S (Transmitter)
Items Specification Remarks
Oscillation type Crystal based PLL oscillation
RF power 5 mW / 10 mW (e.r.p)
Frequency stability +/- 15 kHz
Noise reduction Compander
Spurious emission 1 uW max.
Deviation 20 kHz 1 kHz @ -25 dBv
AF input level - 113 to -13 dBv 1 kHz
AF input impedance 12 kΩ or more
Maximum DC input to AF input 7 V DC max
Supply voltage 4.2 to 6 V 3.6 to 7 V *1
Consumption current 5mW: 50 mA
10mW: 60 mA
STB(open): <1mA
Dimensions 36 x 26 x 8 mm Excluding protrusion
Weight 13 g
*1 Supply voltage: 3.6 to 7V – Possible operating range without meeting full specifications
WA-RX-03S (Receiver)
Items Specification Remarks
Receiver type Single super heterodyne
Local oscillator type Crystal based PLL oscillation
IF Frequency 10.7 MHz
Noise reduction system Expander
Receiver sensitivity 21 dBuV (- 92 dBm) S/N 55 dB
Squelch sensitivity Adjustable by external VR
AF output level - 10 dBv Δf = 20 kHz
AF output impedance 20 kΩ or less
Supply voltage 3 to 5 V
Consumption current 45 mA
Dimensions 36 x 26 x 8 mm Excluding protrusion
Weight 13 g
*0 dBv=0.775 V * The data was taken at 25 C unless otherwise specified

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OPERATION GUIDE
TERMINAL DESCRIPTION
WA-TX-03S transmitter module
No. Name I/O Description Equivalent circuit
1 UNA O
LED terminal for unavailable channels.
The terminal is high when any channel
outside CH 1 to 15 is selected.
LED can be powered directly
2 SW0 I Transmitter channel setting terminal
Select channel within 15 programmed
channels
Refer to “Channel table”
SW0 to SW3 are disabled when
STB=H(open).
3 SW1 I
4 SW2 I
5 SW3 I
6 NC -
7 SW5 I
H(open): 5mW
L(GND): 10mW
Power setting is enabled when the module
newly starts transmitting.
SW5 is disabled when STB=H(open).
8 STB I
Terminal for stand-by with power off delay
Set to High(open) to enter standby.
Set to ground when transmitting.
9 AF I Audio signal input terminal
Audio input signal level -113 dBv to -13 dBv
10 VCC I
Power supply (+) terminal
Voltage range is DC 4.2 to 6 V
A power source without ripple noise should
be used.
A protection diode for reverse connection is
provided in the circuit.
11 ANT O
Antenna terminal (RF output)
50 Ω impedance
12 GND I
GND terminal
The ground is for the power supply and
antenna radial.
Connect it to a wide ground plane for efficient
antenna emissions and stable operation.
-
+12kΩ 10uF Terminal
3V
*SW0-3&SW5: 3V when STB=L(GND)
*STB: always 3V
*
*

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WA-RX-03S receiver module
CN1
No. Name I/O Description Equivalent circuit
1 CON I
Terminal for adjustment of mute level.
Connect a 10 to 20 kΩ VR to the terminal for
mute level adjustment.
The mute level is the threshold level of the
received signal field strength so as not to
output the received signal below the threshold
level.
2 LED O
MUTE LED terminal
The terminal is high when mute is in operation.
It is low when the AF signal is output, so that
the LED connecting the terminal works as an
AF output indicator showing the AF output
status.
The terminal is an open collector and is
connected to a 220Ω resistor (Max 10mA).
3 UNA O
LED terminal for unavailable channels.
The terminal is high when any channel other
than CH 1 to 15 is selected.
The LED can be powered directly
4 VCC I
Power supply (+) terminal
The voltage range is DC 3.0 to 5 V
A power source without ripple noise should be
used.
Be sure to connect it with the correct polarity.
To maintain a lower voltage, a protection diode
is not provided in the circuit.
5 AF O
Audio output terminal
Output impedance is 20 kΩ.
Connection to a low input impedance interface
will decrease the output level.
Maximum output level is –10 dBv
When an audio amplifier is used, if the
amplified output is distorted by the MIC input,
insert an attenuator.
6 GND I
GND terminal
The ground is for the power supply and
antenna radial.
Connect it to a wide ground plane for stable
operation.
7 ANT I Antenna terminal (RF input).
50 Ω impedance

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OPERATION GUIDE
CN2
No. Name I/O Description Equivalent circuit
1 SW0 I
Receiver channel setting terminal
Selects a channel within 15 programmed
channels
Refer to “Channel table”
2 SW1 I
3 SW2 I
4 SW3 I
5 NC -
6 NC -
CHANNEL TABLE
CH TX/RX frequency SW0 SW1 SW2 SW3
0 Unavailable H H H H
1 863.125 L H H H
2 863.250 H L H H
3 863.375 L L H H
4 863.500 H H L H
5 863.625 L H L H
6 863.750 H L L H
7 863.875 L L L H
8 864.000 H H H L
9 864.125 L H H L
10 864.250 H L H L
11 864.375 L L H L
12 864.500 H H L L
13 864.625 L H L L
14 864.750 H LLL
15 864.875 LLLL
L = GND
Remarks for integration of the receiver antenna
Please pay due attention to the design of the antenna ground plane based on the general design theory.
Locate the antenna in a place where there are no objects between TX and RX and that is visible from
the transmitter antenna. If a PCB pattern line is used for connection between the antenna terminal and
the antenna you choose, please secure the following pattern width.
PCB thickness (mm) 0.8 1 1.2 1.6
Pattern width (mm) 1.3 1.4 1.7 2.7
(The example above shows a case where a G10 double-sided PCB is used.)

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OPERATION GUIDE
CONNECTION EXAMPLE (WA-TX-03S)

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OPERATION GUIDE
CONNECTION EXAMPLE (WA-RX-03S)

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OPERATION GUIDE
DIMENSION WA-TX-03S
Reference hole position (Top view)