@@@@@@@@@@@@@@ C GAIN VERSUS FREQUENCY PLOT FOR RC FILTER C RC ACTIVE FILTER PROGRAM BY KINCAID AND SHIRLEY C MODIFIED FOR FOCAL BY TOM BEAN & WILLIAM E ROMANS C INPUT PARAMETERS: C T: TYPE OF FILTER (ENTER L FOR LOWPASS;H FOR HIGHPASS) C N: NO. OF POLES (MUST BE EVEN) C KH: CUTOFF FREQUENCY IN KHZ C R: PASSBAND RIPPLE IN DB (0 FOR BUTTERWORTH) C C1: MAXIMUM CAPACITANCE IN NANOFARADS C RE-ENTER VALUES FOR THE ABOVE WHICH WERE USED IN CALCULATING C R1 R2 C1 C2 AND ENTER THE CALCULATED VALUES FOR C2 R1 AND R2 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ C-FOCAL,1969 01.05 A ! ?T N KH R C1 ?,!!;S J=N/2;F I=1,J;A ?C2 R1 R2 ?,!;D 1.46 01.20 T !!"INSERTION GAIN (DB)",!! 01.25 F KX=0,6;T %2,-15+3*KX;T " " 01.30 T !;F KZ=1,6;T " + - - - -" 01.35 T " +",! 01.40 F K=0,36;D 2;D 4 01.45 Q 01.46 S X(I)=R1*R2*C1*C2;S Y(I)=(R1+R2)*C2;S Z(I)=R2*C1 02.02 I (T-12)2.06;S HK=KH*(1+K)/25;G 2.14 02.06 S HK=25*KH/(37-K) 02.14 S B=2*3.14159*HK;F I=1,J;D 3 03.05 I (T-12)3.15 03.10 S GX(I)=(1-X(I)*B^2/1E6)^2+(Y(I)*B/1E3)^2;G 3.20 03.15 S GX(I)=(1-1E6/(X(I)*B^2))^2+(2*1E3/(Z(I)*B))^2 03.20 S G(I)=-FLOG(GX(I))/.230259 04.04 S G=FITR((G(1)+G(2)+G(3)+G(4)+G(5))/.3+.5)+51;F I1=0,20;D 5 04.06 D 6 05.04 S I2=G-3*I1;I (I2)5.22;I (I2-2)5.12,5.08,5.22 05.08 T " *";R 05.12 I (I2-1)5.18;T " * ";R 05.18 T "* ";R 05.22 I (FITR(K/6)-K/6)5.30 05.24 I (FITR((I1+7)/10)-FITR(I1+7)/10)5.26,5.32 05.26 I (FITR(I1/10)-I1/10)5.28,5.34 05.28 I (FITR((I1+3)/10)-FITR(I1+3)/10)5.30,5.36 05.30 T " ";R 05.32 T " +";R 05.34 T " + ";R 05.36 T "+ ";R 06.02 T %4.03, HK,! @@@@@@@@@@@@@