1 REM COAX TRAP PROGRAM - 12/29/93 - Adapted to Model 100 by Ron Wiesen, WD8PNL 2 REM from a program by Andy Griffith, W4ULD 3 L=0:C=0:XL=0:XC=0:N=0:N0=0:A2=0:A1=0:C1=0:RA=0:PI=0:CC=0:N1=0'variable order for speed 10 CLS:PRINT@88,CHR$(27)"p"CHR$(240)STRING$(21,CHR$(241))CHR$(242):PRINT@128,CHR$(245)" Coax Trap Program "CHR$(245):PRINT@168,CHR$(245)" Ron Wiesen WD8PNL "CHR$(245):PRINT@208,CHR$(246)STRING$(21,CHR$(241))CHR$(247)CHR$(27)"q":FORN=0TO999:NEXT:CLS 20 PRINT"This calculates the turns for an antennatrap made from coaxial cable. It shows XL, XC, L and C values. Inputs are the coax cable diameter, capacitance per foot, coil form diameter, and trap frequency.":PRINT 30 INPUT"Results to: 0=SCREEN, 1=PRINTER ";PT:IFPT<0ORPT>1THEN30 40 PRINT 50 PRINTTAB(8);:INPUT"Coax Diameter (in) ";CD:PRINTTAB(8);:INPUT"Coax Cap./ft. (pF) ";CC:CC=CC/12'capacitance/inch 60 PRINTTAB(8);:INPUT"Form Diameter (in) ";D:A=D+CD'mean winding diameter 70 A2=A*A:A1=18*A:C1=40*CD 80 PRINTTAB(8);:INPUT"Frequency (MHz) ";F:PI=3.14159265:RA=2*PI*F 100 REM - INITIAL ESTIMATE OF N 110 N0=INT((570/F)*SQR(CD/A/A2/CC)+.5) 120 REM - FIRST CALCULATION LOOP 130 FORN=N0TON0+20STEP.5:L=A2*N*N/(A1+C1*N):XL=RA*L:C=(A*PI*N+1)*CC:XC=1000000/RA/C:IFXL>=XCTHEN200 140 NEXTN 200 REM - SECOND CALCULATION LOOP 210 FORN1=N-.5TON+.5STEP.05:L=A2*N1*N1/(A1+C1*N1):XL=RA*L:C=(A*PI*N1+1)*CC:XC=1000000/RA/C:IFXL>=XCTHEN300 220 NEXTN1 300 REM - PRODUCE RESULTS 310 IFPT=0THENOPEN"LCD:"FOROUTPUTAS#1:GOTO340ELSEOPEN"LPT:"FOROUTPUTAS#1 320 PRINT#1,:PRINT#1,:PRINT#1,USING"Coax: ###.### inch OD, ###.### pF/ft";CD;CC*12:PRINT#1,USING"Coil Form Diameter of ###.### inch";D 340 PRINT#1,:PRINT#1,USING" For Frequency of ####.###### MHz:";F:PRINT#1,USING"XL = ###.### ohm XC = ###.### ohm";INT(XL*10+.5)/10;INT(XC*10+.5)/10 350 X1=100:IFL<1THENX1=1000 360 X2=100:IFC>=10THENX2=10 370 PRINT#1,USING"L = ###.### uH C = ###.### pF";INT(L*X1+.5)/X1;INT(C*X2+.5)/X2:PRINT#1,USING"Number of Turns = ###.###";INT(N1*100+.5)/100:W=INT(INT(N1+.5)*CD*100+.5)/100:CL=INT((A*PI*N1+1.5*W)*10+.5)/10 380 PRINT#1,USING"Winding Length = ###.### inch";W:PRINT#1,USING"Coax Length = ###.### inch";CL:PRINT#1,USING"Effective Length = ###.### inch";INT(CL*8.8+.5)/10:CLOSE#1 400 REM - MENU FOR RE-RUN 410 IFPT<>0THENPRINTELSEPRINTTAB(8);:INPUT"Press ENTER to continue";X1 420 CLS:PRINTTAB(4)"1 - Repeat from Beginning":PRINTTAB(4)"2 - Repeat for New Frequency Only":PRINTTAB(4)"3 - New Form Diameter & Frequency":PRINTTAB(4)"4 - Exit Program":PRINT:PRINTTAB(8);:INPUT"Choose (1 - 4)";X1:PRINT 430 IFX1=1THEN50 440 IFX1=2THEN80 450 IFX1=3THEN60 460 IFX1=4THEN500 470 GOTO420 500 MENU