adjustment of the relay solenoid. By moving the solenoid longitudinally by 

 the use of these screws the tension of the spring extension from the magnet 

 bar can be adjusted to locate the timing stylus shank so that it operates 

 freely in the clearance hole,, The ideal position of the armature from the 

 magnet bar is with the gap as small as' possible with the sliding bar at the 

 rest position. At the end of the stroke of the sliding bar the timing 

 stylus shank sleeve should just clear the opening in the plate in which it 

 operates o Too much tension either front or back will cause the mechanism 

 to bind, 



75c In the lower part of Fig 25 are shown the two adjusting screws which 

 hold the guide plates for the timing stylus slide bar The adjustment here 

 allows a crosswise movement of these plates so that both the timing stylus 

 shank and the magnet bar spring can be adjusted centrally with the sliding 

 bar and the writing scriber*, 



End View 



76' e Fig, 26, an end view of the relay solenoid, shows the magnet bar with 

 its spring, and the stylus shank with the stylus projecting,, It is to be 

 noted that the magnet bar spring just barely clears the side of the main 

 stylus bracket and is also above the slot for the writing scriber guide pin„ 

 The end- of the magnet bar spring which fits the slide bar must be clear of 

 the slot in which the guide pin of the writing scriber operates „ 



MAGNETIC TAPE RECORDERS 



_and Connections 



77o The magnetic tape recorders are located in the lower sections of Rack 

 2 (Fig., 7) and Rack 3 (Fig, 10) „ Their schematics are shown in Figs, 48 and 

 49, and on panel and chassis insignia they are referred to as 

 They consist of an amplifier and a vicalloy-tape magazine „ 



78. Normally, one recorder is in constant operation., The other is turned 

 on by the station operator to maintain continuous station monitoring after 

 the operating recorder has been switched to HOLE to preserve a shot arrival,, 

 The magnetic tape recorder in use and switched to is constantly re- 

 cording and erasing; it therefore records the signal in its entirety n 

 Simultaneously, it records the 3-kc pulses from the chronometer time control 

 unito 



79 « The signal input lead, to each Mirrophone is from the receptacle on the 

 rear of the chronometer time control- and phone monitor chassis labeled 



It is plugged into the jack receptacle marked 

 on the front panel of the proper Ri*ck (either Rack 2 or Rack 3^ 

 Figo 6 or 9), and the signal is applied directly to the input of the tape 



- 19 - 



