118


'0.00      0.50     1.00    1.50     2.0      2.50     3.00    3.50     '.00
                                 TIME (SECONDS)







* 0
  J .,,.~~. .;.                                ;;





l


                I                      _  _  _ I

                                 .S  2.0      2.50     3.00    3.50      .0
                                 TIME (SECONDS)





   Figure 7-5. Tracking error: ref. = 1.5 Hz sinusoid with amplitude
                of 150; dist. = 0; I.M. frequency = 1.5 Hz