AODC Emergency Transponders

Meet The 6G® Product Range

Sonardynes AODC Emergency Transponders have been developed to satisfy the requirement for a portable and economic device for fitting to Diving Bells which will provide an up-to-date means of emergency relocation.

They also satisfy the growing need for small, medium-range transponders, which can be easily handled/ deployed by divers and vehicles and used for making high precision measurements and assisting area searches in low visibility.

Operating in the frequency band of 37-40kHz, these transponders have been developed to meet stringent AODC requirement. They operate in the ‘Sequential Mode’ and are interrogated on their own individual preset interrogation frequency (Channels A or B). The reply frequency is preset to the ’emergency reply frequency’ of 37.5kHz.

The excellent transducer response time and stable turnaround delays allows good measurement accuracies to be achieved and the delayed response provides a ‘down to zero’ ranging capability. The output power selected allows a compromise between an acceptable operating life, operation in high levels of noise and as a minimum, an interrogation range of 500 metres.

Technical Specifications :-

Feature Type 8057
Operating Frequency 36-44kHz
Individual Emergency Interrogation Preset during manufacture to Channels A or B
Channel Frequency 38.5kHz & 39.5kHz
Emergency Reply Frequency 37.5kHz
Turnaround Delay 125.8 ms (crystal controlled)
Transponder Source Level 185dB re 1µP at 1 metre
Beam Pattern Hemispherical
Minimum Listening Life In Water Type 7097 6 months (Alkaline) Type 7192 18 months (Lithium)
Number Of Replies @ 85 dB 900,000
Remote Low Battery Indication Listening life of 3 months and minimum reply life of 5 days
Mechanical Construction Anodised aluminium housing
Depth Rating 300 metres
Dimensions (LxDia) 533mm x 69.9mm
Weight In Air 3kg
Weight In Water 1kg


  • Meets AODC requirements
  • Compact, rugged design
  • Minimum interrogation range of 500 metres
  • Choice of operating channels
  • Up to 18 months listening life