Trantec S4.04 Headset System HM33 CH70

Availability: Backorder
Expected: Oct 05, 2022

  • Trantec S4.04 Headset System HM33 CH70, Trantec's simplest plug and play system.
  • Designed to launch you into the world of wireless.
  • Comes with an HM-33 Microphone, a state of the art Beltpack Transmitter and a UHF wireless diversity receiver.
  • Features an Enhanced Frequency Bank system with up to 4 compatible licence-free frequencies.
Our price £179.00 £149.17
- +

Trantec S4.04 Headset System CH70

The S4.04 Series Lapel system comes with an HM-33 Microphone, a state of the art Beltpack Transmitter and a UHF wireless diversity receiver. Featured is an Enhanced Frequency Bank system with up to 4 compatible licence-free frequencies. All built on synthesised PLL quartz tuning technology. Fully utilises the limited space available on Channel 70 whilst maintaining guard bands to protect from adjacent channel interference. Simple easy lock system to synchronise multiple transmitters to receivers.


HM-33 Headworn Microphone


The HM-33 has been designed primarily for the active professional who needs a hands-free operation. It remains in place and feels secure. Suitable for people in sports, journalism, event organising and presentations. The sound quality is pure and does not react to voices where sibilance would otherwise be a problem. It is comfortable to wear over extended periods. The HM33 is perfect for those applications which require a high-performance cost-effective solution. Supplied with a black foam windshield


Beltpack Transmitter S4.04


  • Part of a fully integrated system
  • Transmitter cover unhinges to reveal
  • Selected channel number
  • Infra-red port to communicate with receiver
  • Set button to change frequency
  • Gain control
  • Microphone-Instrument selection switch
  • Input accepts a wide range of pickups, alternative microphones and other electronic gear
  • Gain Control makes it possible to use any alternative miniature electret microphone with a 3.5mm Mini Jack plug.
  • Mic input provides a phantom power voltage for electret microphones.
  • Range of up to 100 metres.
  • Rear Belt Clip ensures belt pack will remain in place.
  • One AA battery gives up to 10 hours at full performance.
  • Low Battery Status indication relayed to receiver.
  • 3.5mm jack socket with heavy plated contacts for absolute reliability.
  • Aerial tuned to carrier frequency for maximum efficiency.
  • Optional lead 3.5mm Mini Jack to quarter-inch jack plug


Receiver S4.04 Series


  • Diversity reception automatically switches between antennas A and B for best reception.
  • Up to four channels can be used simultaneously without interference.
  • Antennas can be set at any angle to maximise best reception. V formation is usually best.
  • Automatic frequency scan searches for best available frequencies LEDs show AF peak level, active channel and diversity channel A or B.
  • Signal Squelch automatically mutes when carrier is not present.
  • Simple Sync locking procedure.
  • Manual and automatic. Locks chosen transmitter to receiver Audio outputs, XLR balanced and Jack unbalanced.


Various accessories are available to enhance the performance and adaptability of the system.

Trantec continues to lead the Radiomic industry with their innovation, consistent performance and build quality. Their products are literally second to none and with the company being UK based, their technical support is the benchmark of the Pro Audio Industry.

Channel 70 is Licence free. Wireless Microphones can tune into frequencies that do not require a licence to operate. There are several licence-exempt areas for PMSE use. (Programme Making and Special Events)

The UHF licence-exempt range is 863.100-864.900 MHz. This is within Channel 70 which has little spectrum assigned to it so limiting the number of users to four. The power is limited by legislation to 10mWatt. There is no limitation to how many frequencies can used in this channel as long as users stay within the confines of the band. More users could be squeezed in but that would jeopardise clear reception and interference from adjacent channels.

There are currently no plans to remove access to Channel 70; it will continue to be licence-exempt for PMSE users.

Channel 70 is adjacent to use of mobile in the 800 MHz band. There should not be any interference however this is the risk taken with the licence-exempt channels.


What's in the Box:

  • HM-33 Headset Microphone
  • Beltpack Transmitter
  • Receiver
  • Receiver Power Supply
  • Operating Manual



Diversity Reception: Antenna Diversity
Sensitivity: 10uV at 45dBA, S/N
Squelch Tone: SQ, Carrier SQ, Noise SQ
Audio Frequency Response: 50Hz – 15kHz
Audio Output Level (Max.): Balanced (XLR socket): -20dBu, Unbalanced(1/4″ jack socket): 10dBu
Power Supply: 12 VDC 500mA
Dimensions: 215(W) x 39(H) x 102(D)mm
Weight: 480g


Beltpack Transmitter
RF Carrier Power: 10mW
Audio Frequency Response: 50 Hz- 15kHz
Audio Input Level: -6dBV (maximum), mic gain 0dB
Battery Life: Approximately 10 Hours
Power Supply: 1AA size battery, 1.5V
Finsh: Resin, coating
Dimensions: 62(W) x 100(H) x 25(D)mm
Weight: 85g with battery