Multi Channel Wireless Audio Transmitter and Receiver (15 Channels)WA-TX-03S, WA-RX-03S

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.


  • 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)


  • Audio guiding in museums
  • Tour guide systems
  • Wireless conference systems
  • Wireless microphone systems for amateur users
  • Various audio transmissions
  • Voice monitoring



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

Data Sheet

Version 1.3 PDF

Operation Guide

Version 1.0 PDF

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


Operation Guide

Version 1.0 PDF

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.


External View


Board x 1
Antenna (ANT-RIG-02-R) x 1
Spacer x 4



Board x 1
Antenna (ANT-RIG-02-R) x 1
Spacer x 4



Lead antenna with plug

...more info


Rigid antenna with plug

...more info