OCEAN ELECTRONIC NAVIGATIONAL AIDS 61 



X. Power Requirements — 



The equipment shall 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. 



XI. Operator Controls — 

 On-off switch (all power) . 

 Bearing cursor knob. 

 Range marker knob. 

 Continuous gain control. 



Limited intensity control; focus to be essentially independent of in- 

 tensity. 



Range selector (positive range scale indicator) . 



STC, FTC selector switch for varying degrees of any or all (sea return 

 and interference suppressor. 



Azimuth scale light control. 



Antenna-reversing switch (optional). 



Safety devices shall be incorporated to make it impossible for the operator 

 to damage the equipment by manipulation of the controls. 



XII. Construction Features — 



Replacable units with chassis type assembly. 

 Fuse alarms. 



Mounting, tropicalizing and weatherproofing shall be suitable for in- 

 tended installation. 



XIII. 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. It is sug- 

 gested that the radio frequency components, the antenna assembly and the 

 indicator be manufactured in separate units. 



XIV. Special Provisions for Future Modifications — 



As contemplated, 10 centimeter Radar beacon objectives will meet 10 centi- 

 meter commercial Radar design objectives on the common ground that the 

 Radar will be able to transmit within the frequency limits and with peak 

 radiated powers as specified herein, and further that it will be capable, 

 as constructed or with minor modifications, of receiving beacon signals on 

 3256 megacycles. Beacon operation will be improved if the operating fre- 

 quency of the Radar is in that portion of the Radar band as close as prac- 

 ticable to the beacon frequency. 



XV. Optional Features — 



Remote PPI's, with controls independent of the indicator controls, for 

 installation in the chartroom, commanding ofiEicer's quarters, etc., have ob- 

 vious uses on certain classes of vessels. Such remote PPI's may have a means 

 for comparison with navigational charts and/or giving an expanded presenta- 

 tion of a selected area of the PPI. 



An "hours run" meter to facilitate the replacement within the required 

 period of components which deteriorate with age. 



XVI. 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. It is reiterated that nothing in these speci- 

 fications should be construed to limit development and improvement of Radar 

 circuits or equipments extant. 



Advisory Minimum Specification Brief No. 2 {Surface Search and Navigational Radar) 



I. Designation — 



Surface search and navigational Radar. 



II. General Description — 



This is to be a 3- or 10-centimeter surface search Radar primarily designed 

 for ocean-going vessels to provide early warning of approaching vessels and 

 navigational dangers on the open seas as well as fair resolution for navigation 

 in restricted waters. 



842041—50 5 



