C. SUBBOTTOM DEPTH RECORDER (SDR) (cont^d) 



6. Transducers: 



Type: Transmitter: sparker, or RASS (which uses liquid 

 propane at a rate of one pound per hour and oxygen at a 

 rate of 30 cubic feet per hour with an approximate 

 volumetric ratio of 1:5, respectively); Receiver: hydro- 

 phone 

 Location: Hull-mounted, or towed astern (recommended) 

 Transmitter life: Sparker: 4 hours (average); RASS: 30 

 hours (average) 



7. Acoustic power: 



Sparker: 10 5 watts (estimated); RASS: 10 7 watts (estimated) 



8. Acoustic frequency: 



Approximate range: Sparker: 30 c.p.s. to 5 kilocycles; RASS: 



30 c.p.s. to 3 kilocycles 

 Peak: Sparker: 60 to 150 c.p.s.; RASS: 35 c.p.s. 



9. Acoustic pulse length: Sparker: 4 to 10 milliseconds; RASS: 6 



to 15 milliseconds 



10. Acoustic pulse repetition rate: Sparker: 1, 2, 3, or 4 pulses per 

 second; RASS: 1 or 2 pulses per second 



11. Receiver band pass filter network: Adjustable 



High pass: 7 c.p.s. 

 Low pass: 7 kilocycles 



12. Graphic record: 



Scale: to 600, 800, 1,200, and 2,400 feet 



Paper type: Dry, electrosensitive (Teledeltos NDA), when 



used with the Precision Depth Recorder 

 Paper dynamic range: About 10 db 

 Precision of time base: 3 parts in 1 million 



13. Shipping weight: About 2,500 pounds (including recorder) 



14. Relay rack (19 inches wide) panel space: About 80 inches 



(2 racks; may not include power supply) 



15. A.C. power consumption: Sparker: 3 kilowatts; RASS: 1 kilowatt 



D-5 



