ADCP-75-214 • Issue 2 • September 2006

4TROUBLESHOOTING 4-PORT CLEARGAIN DUAL INLINE DUAL DUPLEX TOWER MOUNTED AMPLIFIERS

Trouble is visually indicated by LED's or no LED illumination on a specific MHU, swap Bias-T cables on PDU ports to see if trouble remains or moves (reference Figure 8). See Figure 10 for possible trouble points.

ANTENNA

JUMPER

FEEDLINE

JUMPERS

HARD LINE

NOTE: COMMON FAILURE

POINTS ARE THE ANTENNA

AND FEEDLINE JUMPERS/

CONNECTORS.

HARD LINE

SHELTER

TEST

POINT

CHECK IF EXTERNAL JUMPERS

OR SURGE PROTECTORS ARE PRESENT.

IF A SURGE PROTECTOR IS ANYWHERE

BETWEEN THE BIAS-T AND THE MHU

IT MUST BE ABLE TO PASS DC.

ANTENNA

JUMPER

MASTHEAD UNIT (MHU)

21299-A

Figure 10. Tower Mounted Amplifiers

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© 2006, ADC Telecommunications, Inc.