Array Solutions - SAL12/20/30 - Mark II Manual – Rev. 1.5.1 – September, 2018
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The Loop Polarity and Array Delay Test
The purpose of this test is to measure the difference between signals in both the UNI-
directional and BI-directional modes and compare the results to the expected results
based on experience and modeling using the factory provided dimensions.
1.
Press the UNI button to select the UNI directional mode.
2.
Press the direction change arrow so that the LED’s point to the northeast
direction.
3.
Tune to an AM Broadcast station coming from a northeast direction.
4.
Observe the signal strength from the station.
5.
Now, press the BI button to select the BI directional mode and observe the signal
strength.
6.
The signal in the BI mode should be much STRONGER than the UNI mode.
Refer to the graphs below for your array to see what this difference should be.
Note that the difference is based on the frequency For example, at 1000 KHz, the
difference for the AS-SAL-20 should be 16dB and for the AS-SAL-12 should be
22dB.
7.
Press the direction change arrow so that the LED’s point to the northwest
direction.
8.
Tune to an AM Broadcast station coming from a northwest direction.
9.
Observe the signal strength from the station.
10.
Now, press the BI button to select the BI directional mode and observe the signal
strength.
11.
Refer to the graphs below for your array to see what this difference should be.
Note that the difference is based on the frequency For example, at 1000 KHz, the
difference for the AS-SAL-30 should be 12 dB, for the AS-SAL-20 should be 16
dB and for the AS-SAL-12 should be 22 dB.
o
Note: If you don’t see a difference in the signal strength, then either the balanced
feed line polarity is incorrect for the respective loop, there is a problem with the
delay line connection, or the couplers are not located at the correct distance from
the mast.
