Troubleshooting - JDS Uniphase HST-3000 User Manual

Chapter 8 Wideband testing
Performing WBTIMS measurements
Troubleshooting The SDI-100 is directional in terms of the received signal
strength. Looking down on the top of the antenna, the recep-
tion pattern is circular, as shown (in yellow) in Figure 5.
Direction of strongest Direction of strongest
Top of antenna
reception reception
Figure 5 Copper Testing signal reception
When the broad flat surface of the antenna (the face) is
pointed towards a radiating source, the received signal
strength is at a minimum, or what is sometimes called a null.
This null is very sensitive to the position of the antenna and a
slight rotation in either direction will result in a rapidly
increasing received signal.
When the narrow edge of the antenna is pointed towards a
radiating source, the received signal strength is at a
maximum, or what is sometimes called a peak. This peak is
not very sensitive to the position of the antenna and a slight
rotation in either direction will not result in a rapidly decreasing
received signal.
For this reason it is recommended that the initial approximate
location of the radiating interferer be done with end of the
antenna, searching for a peak signal. After an approximate
bearing is established, the flat face of the antenna should be
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HST-3000 Copper Testing User's Guide