OCEAN ELECTRONIC NAVIGATIONAL AIDS 63 



Over-all noise above KTAf — 15 decibels maximum. 

 Features — 



Automatic frequency control or equivalent. Fast time constant and 

 sensivity time control equivalent. 



IX. Power Supply — 



The equipment should be designed to take power from a source of 115 volts, 

 60 cycles per second, single phase with a regulation of ±10 volts ±2 cycles 

 per second. In the case of direct-current equipped ships and ships with 

 poor regulation, auxiliary power equipment will be necessary. 



X. Operator Controls — 

 On-off switch (all power). 

 Bearing cursor knob. 

 Range marker intensity knob. 

 Continuous gain control. 



Limited intensity control ; focus to be essentially independent of intensity. 

 Range selector (positive range scale indicator) . 



STC and FTC selector switch for varying degrees. (Sea return sup- 

 pressor) . 

 Azimuth scale light control. 

 Antenna-reversing switch (optional). 



XI. Construction Features — 



Replacable units with chassis type assembly. 

 Fuse alarms. 



Mounting, tropicalization, and weatherproofing shall be suitable for in- 

 tended installation. 



XII. Installation Features — 



The antenna assembly must be so mounted as to provide 360° clearance 

 to the horizon. The indicator is to be mounted in the pilot house. To facili- 

 tate this arrangement on all types of vessels it is suggested that the radio fre- 

 quency components, the antenna assembly, and the indicator be manufactured 

 in separate units. 



XIII. Special Provisions for Future Modifications — 



The Radar should be capable as constructed or with minor modification 

 of receiving Radar beacon signals on 3256 megacycles for a 10-centimeter 

 Radar or on 9310 megacycles for a 3-centimeter Radar. Beacon operation 

 will be improved if the operating frequency of the Radar is in that portion of 

 the Radar band as close as practicable to the beacon frequency. 



XIV. Remarks — 



Standard Navy flange for antenna mounting, standard video output and 

 standard trigger output are specified to facilitate ease of conversion for mili- 

 tary use. 



The phrase "or equivalent" is applicable to all the above items. As Radar 

 is still in a progressive stage, these specifications are intended merely as a 

 mutual voluntary starting point. In using these specifications the constant 

 improvement and development of Radar should be contemplated and kept 

 in mind. 



Advisory Minimum Specification Brief No. 3 [Anti-Collision Radar) 



I. Designation — 

 Anticollision Radar. 



//. General Description — 



This is to be a surface search Radar primarily designed as an anticollision 

 device with a limited value for navigational purposes. 



///. Operational Requirements — 



Designed for operation by pilot house personnel with little or no technical 

 training but with specialized operational training in the interpretation of 

 equipment data. The operation of this equipment must not cause interference 

 to or be affected by other navigational and electronic equipment normally 

 carried aboard ship, 



IV. Performance — 

 Range maximum : 



Equipment must be capable of absolute indication of the presence of a 

 C2 type cargo vessel or equivalent at a distance of 7 miles. 



