Array Solutions - SAL12/20/30 - Mark II Manual – Rev. 1.5.1 – September, 2018
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Coupler Positioning
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For each loop, position each coupler per the diagram and table below.
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Allow the balanced line from the coupler to freely drape from the coupler to the
controller being careful that it does not touch the ground or wrap around the loop.
Keep the line well away from the ground. You can use string or tie-wraps to
suspend it up in the middle to the horizontal loop wire.
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Note: The delay line length and coupler position largely set the directional
pattern. But you can adjust the null angle off the back by moving the couplers
on the loop. One trick is to use a small RF source like an antenna analyzer
perhaps located 500 feet away or even up your tower at an angle of say 15
degrees to the SAL Array. Then adjust the SAL for maximum F/B ratio by
moving the couplers positions six inches at the time. When further optimization
is needed move couplers in three inches steps. Each coupler must be moved the
same amount towards or away from the mast. See the Optimization section of
this manual. A reliable signal source like a broadcast station which its position
relative to the SAL antenna is known can be used to optimize the front to back
of the antenna. Keep in mind that at times near dusk and down the propagation
will change and incoming wave angles will do as well and the front to back can
vary a great amount while this propagation conditions are changing.
