TM 5-3895-383-24 4. The  maximum  frequency  should  be  controlled  by  the electrical  signal  from  the  variable  frequency  controller. If the correct maximum frequency cannot be obtained by adjusting "P3" low amplitude-maximum frequency potentiometer (11), turn servo valve neutral adjustment screw (14) counterclockwise.  This will ensure that the movement of the servo piston is not limited. 5. Remove   the   plastic   cover   from   servo   valve   neutral adjustment screw (14). Loosen the jam nut arrangement and turn the servo valve neutral adjustment   screw   counterclockwise   for   approximately two turns. 6. Repeat Steps 2 through 3.  When the correct maximum frequency  for  low  amplitude  has  been  obtained,  servo valve  neutral  adjustment  screw  (14)  should  be  turned clockwise   until   the   frequency   is   slightly   decreased. Then, servo valve neutral adjustment screw (14) should be rotated counterclockwise for one half turn. 7. Hold  the  screw  and  tighten  the  jam  nut  arrangement. Install the plastic cover. 8. When  the  frequency   is   correct,   stop   the   engine   and remove all tooling. Variable Frequency Electrical Control - Test and Adjust (If Equipped) SMCS Code:  6606-025-EL; 6606-081-EL Personal injury or death can result from sudden machine movement. Sudden  movement  of  the  machine  can  cause  injury  to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine. NOTICE To  avoid  damage  to  the  vibratory  system  during  testing, always perform the testing with the vibratory drum on top of   tires   or   on   loose   dirt.      Tires   will   simulate   a   non- compacted soil condition. Never  operate  the  vibratory  system  when  the  machine  is on concrete. NOTICE If a testing time longer than three (3) minutes is required, rotate   the   drum   periodically   in   order   to   lubricate   the eccentric weight shaft bearings. Table 13 Required Tools 6V-7070 Digital Multimeter (or equivalent) 1 Fabricated Wiring Harness 1 Voltage Regulator Test NOTE: Before you perform this test, the condition of fuse (5),  which  is  located  on  the  variable  frequency controller (1) should be verified. Illustration 66 Control Console (1) Variable frequency controller.  (5) Fuse. 11-58