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Full Version: (25) Two-Tower Patterns
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An excerpt from the Pocket Calculator & the D.A., George W. Ing, Broadcast Management Engineering, June 1978 {pgs. 86-94}

"… This is Part 3 {how to use a pocket calculator to obtain the horizontal and vertical plane patterns for a two tower directional antenna system} of a series of articles on the use of the programmable calculator for solving broadcast engineering problems. Part 1 appeared in July '77 and Part 2 in January '78 … "
ps:parts 1-3 are posted in HP Forums / Not HP Calculators / Not remotely HP Calculators / (SR-56) Problem Solving with … (1/3); (2/3); (3/3) …
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HP -25 program
Now we will describe an alternate solution for the horizontal pattern using an HP-25 calculator. Instead of the cosine law formula we will use polar/rectangular coordinate conversion, for which the HP calculators are well-suited.
As shown at the beginning of this article, the field at each observation point around the array is the sum of a reference vector, and a #2 vector which changes with azimuth angle. The two polar form vectors are changed to rectangular form for addition. Then the sum of vectors is changed back to polar form. Only the magnitude of this vector is required. Multiplying by the "K" factor gives the predicted inverse field strength …
HP-25 Program For Two-Tower Patterns

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Reference URL's
• HP Forums: https://www.hpmuseum.org/forum/index.php
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