Purpose: 



(1) For position fixing in making oceanographic 

 measurements. 



(2) For locating free floating or anchored buoys, 

 instrument capsules, and nets. 



1. 1231 Buoy or Instrument Capsule-mounted Transceiver 



Module (135) 



Specifications and requirements: 



(1) The unit shall transmit a coded identification 

 signal whenever it is activated by a coded inter- 

 rogation signal. 



(2) The unit shall not respond to any signal that does 

 not contain its own particular code. 



(3) The transmitter shall turn itself off when trans- 

 mission is completed. Duration of transmission 

 shall be no longer than required by the interroga- 

 tor for obtaining its bearing. 



(4) It shall be possible to change the code by replac- 

 ing a plug-in unit within the module. 



(5) The range shall be at least 50 miles when used 

 with the shipboard or airborne interrogator. 



(6) The module shall contain internal batteries or 

 other power supply sufficient for at least 30 days 

 of continuous receiver and intermittent trans- 

 mitter operation. Provision shall be available to 

 increase life of power supply to at least 6 months. 

 No maintenance shall be required during this 

 period. 



(7) Only nonspillable or dry batteries shall be used. 



(8) The module shall be capable of normal operation 

 without maintenance after being submerged to a 

 maximum depth of 2, 500 meters for at least 30 

 days. 



(9) The module shall operate reliably over the tem- 

 perature range of -25° to 50° C. 



(10) The maximum weight of the module complete 



with antenna and internal power source shall not 

 exceed 40 pounds, exclusive of pressure case, if 

 any. 



1. 1232 Shipboard or Airborne Interrogation Module. • • (25) 

 Specifications and requirements: 



(1) This module shall allow the operator to interro- 



427 



