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I am looking for a .xls spreadsheet (or something that works under LINUX),
to calculate the equations for matching common maritime mobile HF whip antennas: 8 ft 10 ft 15 ft 23 ft 40 ft (backstay, approx 5/8 on 20 Meters) I want to calculate the matching parameters including voltages generated in the tuner for the 1.8 3.5 7 10.1 14 21 28 MHz ham bands and the 2 4 6 8 12 16 and 22 MHz marine bands. The ARRL ANTENNA HANDBOOK, 18th edition, chapter 18, has some equations and a table of calculated values for a 8 ft whip on ham bands. I wish to duplicate the calculations and figure out the voltage maximums for component values for, say, 100 W key down power. Take for example the 1st row of the table: BASE LOADED 8ft whip F=1.8 MHz Loading L = 345 uH Rc Q=50 = 77 ohms Rc Q=300 = 13 ohms Rr =0.1 ohms Feed R = 23 ohms Matching L = 3 uH Now at 1.8 MHz XL of 345 uH = +j3902 ohms Do I calculate the current from P=I*I*R so for Rr = 0.1 ohms, I = sqrt(100/Rr) = 31.6 A so V XL is I*R = 31.6*3902 = over 123 KV? (seems excessive) or do I use the R values of 77, 13, or 23 ohms? (4.4 KV, 57 KV, 8.1 KV )? Do I multiple all RMS voltages by sqrt(2) to convert RMS to PEAK? Greg VE0ACR gblair _at_ sympatico _dot_ ca |
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