The WA-TX-03S / WA-RX-03S are 15 ch multichannel audio modules that operate in the European harmonized 863 - 865 MHz band with RF power selection of 5 and 10 mW. 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 to 865 MHz European Audio band
- 15 channels, 125 kHz steps
- 50 Hz to 13 kHz audio response
- Selectable RF output (5 mW and 10 mW)
- Low power operation
- Adjustable mute level
- Small size for embedding in user equipment
- RED compliant (EN301 357)
Applications
- Audio guiding in museums
- Tour guide systems
- Wireless conference systems
- Wireless microphone systems for amateur users
- Various audio transmissions
- Voice monitoring
Specifications
Common
| Parameter | Specification | Remarks |
|---|---|---|
| Applicable standard | RED compliant (EN 301 357) UK Radio Equipment Regulations 2017 |
|
| Emission type | F3E | |
| Frequency | 863 to 865 MHz | |
| Number of RF channels | 15 channels | 125 kHz step |
| Operating distance | 50 m | Line-of-sight |
| S/N ratio | 90 dB or more | W/IHF-A Filter |
| Audio Frequency response | 50 Hz to 13 kHz | +/-3.5 dB |
| T.H.D | 2% | AF 1 kHz, Dev. = 20 kHz |
| Emphasis | 50 us | |
| Operating temperature | 0 to 50 degree C |
Transmitter Part
| Parameter | Specification | Remarks |
|---|---|---|
| Oscillation type | Crystal based PLL oscillation | |
| RF output power | 5 mW / 10 mW | e.r.p |
| Noise reduction | Compander | |
| Spurious emission | < 1 uW | |
| Deviation | 20 kHz | 1 kHz @ -25 dBv |
| Audio input level | -113 to -13 dBv | 1 kHz |
| Audio input impedance | > 12 kohm | |
| Maximum DC input to AF input | < 7 V DC | |
| Supply voltage | 4.2 to 6.0 V DC *1 | |
| Supply current | 50 mA at 5 mW 60 mA at 10 mW < 1 mA at STB (open) |
|
| Dimensions | 36 x 26 x 8 mm | |
| Weight | 13 g |
*1 Supply voltage: 3.6 to 7 V
Possible operating range without meeting full specifications.
Receiver Part
| Parameter | Specification | Remarks |
|---|---|---|
| Receiver type | Single super heterodyne | |
| Local oscillation type | Crystal based PLL oscillation | |
| IF frequency | 10.7 MHz | |
| Noise reduction type | Expander | |
| Receiver sensitivity | -92 dBm | S/N 55 dB |
| Squelch sensitivity | Adjustable | by external VR |
| Audio output level | -10 dBv | Dev. 20 kHz |
| Audio output impedance | < 20 kohm | |
| Supply voltage | 3.0 to 5.0 V DC | |
| Current consumption | 45 mA | |
| Dimensions | 36 x 26 x 8 mm | |
| Weight | 13 g |
External view
WA-TX-03S
WA-RX-03S
Operation Guide
| Version 1.0 |  |
|---|
Supplementary Information
| Wireless audio transmitter and receiver WA-TX-03S WA-RX-03S video |  |
|---|---|
| Test board for WA-TX-03S WA-RX-03S audio modules video | |
Application Notes
| Enhancing reception with the WA-TX-03S and WA-RX-03S audio modules | |
|---|---|
| Wireless audio module wiring example | |
Parts Change Notice (PCN)
| PCN2391001 (Oct. 2023) | |
|---|---|
| PCN2121001 (Aug. 2021) | |
Product Discontinuation Notice (PDN)
| PDN2504001 (Apr. 2025) | |
|---|
Evaluation Tools : WA-TBT-03S, WA-TBR-03S
This test board is developed to allow you to evaluate the performance of WA-TX-03S and WA-RX-03S without any additional components. The board consists of a DC/DC converter, LEDs, a battery case, switches and volume control.
WA-TBT-03S and WA-TBR-03S do not include modules WA-TX-03S and WA-RX-03S. Please make sure to order them if needed.
Features
External View
WA-TBT-03S
Antenna (ANT-RIG-02-R) x 1
Spacer x 4
WA-TBR-03S
Antenna (ANT-RIG-02-R) x 1
Spacer x 4
Accessories
SJ050011, SJ060011
These female connectors fit onto the SP060022 connector for PCB mounted connections. Please refer to the part numbers below.
![[ Video ] [ WA-TX-03S, WA-RX-03S ] - Introducing the evaluation boards to test audio transmitter and receiver.](https://www.cdt21.com/wp/wp-content/uploads/2023/01/test-board-for-wa-03s.png)
![[ Video ] [ WA-TX-03S, WA-RX-03S ] - Introducing the wireless audio transmitter and receiver for the European harmonized 863 - 865 MHz band.](https://www.cdt21.com/wp/wp-content/uploads/2023/01/wireless-audio-transmitter-and-receiver.png)
- What is the difference between the WA-TX-03-R,WA-RX-03-R and WA-TX-03S,WA-RX-03S?
- Why use analogue FM for your WA-03 modules? Why not use digital?
- What is the response time between input and output signal when using audio module?
- How many channels are usable with the WA-TX-03S, WA-RX-03S at one time?
- How does temperature affect the WA-TX-03S and WA-RX-03S operation?
- Is full duplex communication possible between the WA-TX-03S, WA-RX-03S?
- What kind of inputs can the audio modules accept?
- I want to know about the operation of the standby terminal of the WA-TX-03S
- Is it possible to see the RSSI output level of the WA-RX-03S?
- What are the important points to remember when the WA-TX-03S, WA-RX-03S module is operated on the test board which enables the channel and mute level to be changed?
- Is it possible to connect WA-03 modules to a 16 Ω speaker?
- I want to put the RF module in my enclosure? What do I need to be careful of?
- There is a problem with communication range. What is the problem? What should be checked?
- How should the antenna be handled?
- Can Circuit Design module communicate with a tablet?
- I'd like to use my own antenna on your module. Where can I find the suitable connector (e.g. SP060022)?