Performing Coarse Level Adjustment (Conventional Systems PL/ DPL Adjustment)

Prerequisites:

The MLC 8000 Analog Comparator/MLC 8000 Subsite Link Converter is already codec calibrated to produce -10 dBm +/-1.5 dB.
NoteFor systems with the CSCI, with audio and PL enabled, set the audio to maximum, which is approximately -7.3 dBm out of the CSCI, and make sure that the system is not over deviating. This setting ensures the CSCI is functioning properly and, since the gain added to the RX TLP Clear is after the limiting, ensures that system gain is not high.

Procedure:

  1. Disconnect the audio lines between the comparator and CSCI.
  2. Key up a radio and verify that it is assigned to the channel under test.
  3. With a service monitor, measure the deviation of the received PL/DPL. (With the audio lines disconnected, no audio is present in the received modulation.)
  4. Using the CSCI (R141), adjust the PL/DPL data for 20% system deviation. (500 Hz for 896 systems, 800 Hz for 821 systems, or 1 kHz for VHF, UHF and 806 systems.)
    NoteThe 20% system deviation is PL/DPL code specific. For example, if your system uses the PL code of 151, then the coarse level PL/DPL calibration is for the 151 PL code. If your system changes to 218, then re-execute the coarse level PL/DPL calibration, this time for the 218 PL code.