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Ham Radio
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Ham Radio CD-ROM (Emerald Software) (1995).ISO
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antenna2
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lpda.bas
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BASIC Source File
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1986-08-10
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1KB
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46 lines
10 CLS
20 REM 5/20/86
30 T$="LOG PERIODIC DIPOLE ARRAY DESIGN":L=1:GOSUB 450
40 REM AHMAD FAIZAL MOHD ZAIN
50 DIM L(200)
60 :
70 PRINT:PRINT:PRINT
80 INPUT"ENTER MINIMUM FREQUENCY (MHz) ";FMIN
90 INPUT"ENTER MAXIMUM FREQUENCY (MHz) ";FMAX
100 INPUT"ENTER SCALE FACTOR (TAU) ";TAU
110 INPUT"ENTER SPACING FACTOR (SIGMA) ";SIGMA
120 :
130 ALPHA=(360/3.141592)*ATN((1-TAU)/(4*SIGMA)) 'ANGLE OF VERTEX
140 N=INT(LOG(FMIN/FMAX)/LOG(TAU)+2!) 'NUMBER OF ELEMENTS
150 LAMBDAMAX=300/FMIN
160 :
170 PRINT:PRINT
180 PRINT"NUMBER OF ELEMENTS NEEDED ";N
190 PRINT USING "ANGLE OF VERTEX = ##.##";ALPHA;:PRINT" DEGREES"
200 PRINT: PRINT"THE ELEMENTS ARE":PRINT
210 L(1)=LAMBDAMAX/2:I=1:GOSUB 370
220 :
230 FOR I=2 TO N
240 L(I)=TAU*L(I-1)
250 SPACING=2*SIGMA*L(I)
260 GOSUB 370
270 NEXT
280 :
290 XMAX=L(1)/(2*TAN(ALPHA*3.141592/180))
300 XMIN=L(N)/(2*TAN(ALPHA*3.141592/180))
310 X=XMAX-XMIN
320 PRINT
330 PRINT"LENGTH OF ARRAY = ";X;" METERS"
340 PRINT:PRINT
350 :
360 GOTO 390
370 PRINT "LENGTH (";I;:PRINT USING ") = ##.###";L(I);:PRINT USING " SPACING = ##.###";SPACING
380 RETURN
390 T$="DO YOU WANT TO RUN THIS PROGRAM AGAIN (Y/N)? ":L=23:COLOR 20,0:GOSUB 450:COLOR 7,0
400 AN$=INKEY$
410 IF AN$="Y" OR AN$="y" THEN RUN
420 IF AN$="N" OR AN$="n" THEN END
430 GOTO 390
440 :
450 LOCATE L,(80-LEN(T$))/2+1:PRINT T$:RETURN 'SUBROUTINE TO CENTRE TEXT