OCEAN ELECTRONIC NAVIGATIONAL AIDS 59 



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. — 

 Replaceable units with chassis type assembly. 

 P\ise alarms. 



Mounting tropicalizing and weather proofing shall be suitable for 

 Intended 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. To 

 facilitate this arrangement on all types of vessels it is suggested that the 

 radio frequency components, the antenna assembly, and the indicator bs 

 manufactured in separate units. 



XIV. Special Provisions for Future Modifications. — 



As contemplated, 3-centimeter Radar beacon objectives will meet 3-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 

 9310 megacycles. 



XV. Optional Features. — ■ 



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

 installation in the chartroom, commanding officer's quarters, etc., have obvious 

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

 comparison with navigational charts and/or giving an expanded presentation 

 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 

 military 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 

 specifications should be construed as limiting development and improvement 

 of Radar circuits or equipments extant. 



Advisory Minimum Specifications Brief No. I (lO-cenf/mefer Radar) 



I. Designation.— 



Surface search and navigational Radar. 



II. General Description — 



This is to be a 10-centimeter surface search Radar, primarily designed for 

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

 gational dangers on the open seas as well as good resolution for navigation 

 in restricted waters. 



///. Operational Requirements — 



Designed for operation by bridge personnel with little or no technical train- 

 ing. The operation of this equipment must not cause interference with other 

 aids to navigation or to communication equipment on board and should be 

 adequately shielded to prevent interference to the Radar from other electronic 

 apparatus normally carried. The indicator unit shall not cause appreciable 

 error in a magnetic compass when located more than 6 feet from the indi- 

 cator nor shall other components cause error when located at a distance of 

 more than 15 feet. Mechanical noise from the indicator shall not be audible 

 for more than 20 feet in still air. 



IV. Performance — 



Range : 



Maximum — 30 miles. 

 Minimum — 100 yards. 



