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(HP-67) Calculator Program for Input lmpedance - SlideRule - 01-29-2019 11:20 PM
An extract from An investigation of the possible uses of the normal mode helical antenna in the tactical army, Naval Postgraduate School, MAR 1978.
ABSTRACT
This paper briefly discusses the need for electrically short antennas in the combat maneuver units of the modern field army. A brief history of the work done in the field of helical antennas is presented. An approximate mathematical development is presented which describes the radiation fields of the thin normal mode helical antenna. From the radiation fields, the equations for the polarization ratio and the radiation resistance are developed. A possible design for a tactical VHF-FM antenna to cover the frequency range 30-76 MHZ is presented. The design technique is discussed in detail and a calculator program for computing the input impedance is given. The results of experimental testing are presented and recommendations for improvement are given.
B. HP-67 CALCULATOR PROGRAM FOR INPUT IMPEDANCE
In order to properly use this program, the following data must be supplied and stored as directed: frequency in Hz in register 1, length of the monopole in register 2, radius of the form in register 3, the pitch of the helix in register 4, 30.00 in register 5, 4/3 in register 6, 6.283135308 in register 7, 5.319774201 EEX-10 in register D, 12.5 in register E, and 11811 in register I. The program and data require two complete cards. The following are the instructions for running the program;
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SlideRule