interlocked, allowing them to be phased as one unit. Deep scale operation 

 will normally occur during the 55th to 60th minutes of the hour, -when 

 properly phased. 



COIBTRUCTIOir 



The face of the recorder cabinet is 3U.5 inches wide and 2^ inches 

 deep with a height of 11 inches, and is constructed of a high strength, 

 non-combustible polyester glass (Fig 10). Clean. modern appearance and 

 functional rigidity have been combined in one. The cabinet can be made 

 completely RFI -proof should the need require. A glass panel over the 

 chart area is easily removable to allow operator annotation of the chart. 

 A rigid bar in the front of the machine provides handhold for the opera- 

 tor as well as a means of handling. 



The recorder, designed with consideration of shipboard mounting space, 

 is extremely versatile in the number of ways that it can be mounted, 

 either bulkhead or table. If it is necessary to review past records, 

 the recorder would be mounted with the paper feeding toward the front, 

 allowing the operator to review the past record with ease. If adequate 

 Side space is available, or it is not necessary to review the past 

 record, the recorder can be' turned 90 degrees, allowing the operator to 

 see a true-oriented picture of the bottom profile. 



The construction of the mechanical unit reflects utmost rigidity 

 throughout with the use of castings wherever possible (Figs 11 and 12). 

 The castings are of 356-T6 aluminum as specified in MIL-E-l61|00, insuring 

 good dimensionali stability within the extreme environmental conditions 

 at sea. The modular approach is used for a few significant items, such 

 as the gearbox and the timing pulse generator. These plug-in units are 

 easily replaceable for minimum downtime. All other materials conform to 

 MIL-E-I6UOO or higher requirements to further insure long life and 

 dependable operation. The PFR-193 has been proven to meet the require- 

 ments of MIL-S-901 (Shock) and MIL-STD-I67 (Vibration). 



Access to the electronics is obtained by swinging back the control • 

 panel (Fig 13). The electrical components are packaged in plug-in 

 modules and printed circuit boards which are mounted on a removable flat 

 plate. Numerous test points are used which, when combined with the test 

 meter at the front and the master test point data and function schematic 

 plate, allow easy fault location. Solder-type, fixed-pin connectors 

 have been used throughout the equipment to allow easy field servicing at 

 Hemote locations should the need occur. 



HELIABILITY 



As stated earlier, reliability was one of the most inportant consid- 

 atrations in the PFR-193 design. Every circuit and mechanical detail was 

 aaialyzed through an exhaustive process to minimize failure rates. 



195 



