' VHFPROP.BAS Calculates communications range and reliability ' for VHF terrestrial communications. 27 REM *** PROGRAM IS BASED ON EGLI 28 REM *** PROPAGATION MODEL DESCRIBED 29 REM *** IN "RADIO PROPAGATION ABOVE 30 REM *** 40 MC OVER IRREGULAR TERRAIN" 31 REM *** BY JOHN J. EGLI 32 REM *** PROC. IRE, OCTOBER 1957, 33 REM *** PP 1383-1391 34 REM *** 35 REM *** AND FURTHER DESCRIBED AND 36 REM *** VALIDATED IN "REVIEW OF 37 REM *** PROPAGATION IN THE 470- 38 REM *** 890 MHZ BAND WITH EMPHASIS 39 REM *** ON LAND MOBILE AND CELLULAR 40 REM *** SYSTEMS" BY F.H. PALMER, 41 REM *** COMMUNICATIONS RESEARCH CENTRE 42 REM *** REPORT NO. 1288, FEBRUARY 1976, 43 REM *** OTTAWA, ONTARIO (AVAILABLE 44 REM *** THROUGH N.T.I.S. AS N76-27450) 45 REM *** 90 DEF FN LGT(X) = .4342945 * LOG (X) MENU: CLS PRINT "ษอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออป" PRINT "บ VHF TERRESTRIAL PROPAGATION - MODULE 3 บ" PRINT "ศอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออผ" 155 PRINT 160 INPUT "ENTER FREQUENCY IN MHZ. ";F 180 REM CALCULATE STD DEVIATION(SIGMA) OF PATH LOSS 185 REM AND STORE AS S 190 S = (5.47 * FN LGT(F)) - 3.22 195 PRINT 200 PRINT "ARE BOTH RECEIVING AND TRANSMITTING ANTENNAS HIGHER THAN" 210 PRINT "30 FEET? ENTER YES OR NO: "; 220 INPUT Z$ 230 IF LEFT$(Z$,1) = "Y" OR LEFT$(Z$,1) = "y" THEN 300 235 PRINT 240 PRINT "ARE BOTH RECEIVING AND TRANSMITTING ANTENNAS LOWER THAN" 250 PRINT "30 FEET? ENTER YES OR NO: "; 260 INPUT Y$ 270 IF LEFT$(Y$,1) = "Y" OR LEFT$(Y$,1) = "y" THEN 320 275 PRINT 280 PRINT "COMPUTER ASSUMES ONE ANT. IS HIGHER, THE OTHER LOWER THAN 30'" 290 GOTO 0340 300 E = 1.0 310 GOTO 0345 320 E = 2.0 330 GOTO 0345 340 E = 3.0 345 PRINT 350 PRINT "ENTER HEIGHT OF HIGHER ANTENNA, IN FEET: "; 360 INPUT H1 370 REM H1 IS H(T) IN EGLI MODEL 375 PRINT 380 PRINT "ENTER HEIGHT OF LOWER ANTENNA IN FEET: "; 390 INPUT H2 400 REM H2 IS H(R) IN EGLI MODEL 405 PRINT 410 PRINT "ENTER TRANSMITTER POWER OUTPUT IN WATTS: "; 420 INPUT P 430 P = 10 * ( FN LGT(P / .001)) 440 REM P IS NOW STORED IN DBM, REF 1 MW/50 OHMS 445 PRINT 450 PRINT "ENTER TRANSMITTING ANTENNA GAIN IN DB ABOVE ISOTROPIC: "; 460 INPUT G1 485 PRINT 490 PRINT "ENTER TRANSMITTER TRANSMISSION LINE LOSS" 500 PRINT "IN DB FOR LENGTH ACTUALLY USED-ENTER AS POSITIVE VALUE: "; 510 INPUT L1 505 PRINT 520 PRINT "ENTER ANY ADDITIONAL LOSSES BETWEEN TRANSMITTER AND ANTENNA" 530 PRINT "SUCH AS FILTERS, DUPLEXER OR RELAY LOSSES, IN DB. " 535 PRINT "IF NONE, ENTER 0 : "; 550 INPUT A 560 L1 = L1 + A 565 PRINT 570 PRINT "ENTER RECEIVING ANTENNA GAIN IN DB ABOVE ISOTROPIC: "; 580 INPUT G2 605 PRINT 610 PRINT "ENTER RECEIVING TRANSMISSION LINE LOSS IN DB." 620 PRINT "FOR LENGTH ACTUALLY USED: "; 630 INPUT L2 635 PRINT 640 PRINT "ENTER ANY ADDITIONAL LOSSES SUCH AS FILTERS, DUPLEXERS OR" 650 PRINT "RELAY LOSSES IN DB. IF NONE , ENTER 0 :"; 660 INPUT B 670 L2 = L2 + B 675 PRINT 680 PRINT "ENTER REQUIRED RECEIVED SIGNAL LEVEL IN MICROVOLTS." 690 PRINT "AT RECEIVER INPUT. USE VALUE REPRESENTATIVE OF LEVEL" 700 PRINT "NEEDED FOR GOOD OPERATIONAL S/N, NOT THE TYPICAL " 710 PRINT "10 OR 20DB S/N AS IN THE SENSITIVITY SPECIFICATION." 720 PRINT "IF NOT KNOWN, TRY 3 TIMES THE SENSITIVITY FIGURE :"; 730 INPUT R 735 R = R * 1E-06 740 R = 10 * FN LGT(((R ^ 2) / 50) / .001) 750 REM R IS NOW STORED IN DBM 760 REM CALCULATE ALLOWABLE MEDIAN PATH LOSS IN DB 770 Q = P + G1 - L1 + G2 - L2 - R 776 REM ARRAY Q( ) TO START WITH 1 780 Q(1) = Q 790 Q(2) = Q - 0.53 * S 800 Q(3) = Q - 1.27 * S 810 Q(4) = Q - 1.65 * S 820 Q(5) = Q - 2.30 * S 830 Q(6) = Q - 3.05 * S 840 REM ALLOWABLE PATH LOSS FOR VARIOUS RELIABILITIES CALCULATED. 850 IF E = 1.0 THEN 1000 860 IF E = 2.0 THEN 0900 870 IF E = 3.0 THEN 0900 880 PRINT "ERROR IN PGM LINE 0880" 900 FOR I = 1 TO 6 STEP 1 910 M(I) = Q(I) - 114.8 - (20 * FN LGT(F)) + (20 * FN LGT(H1)) + (20 * FN LGT(H2)) 915 MM(I) = Q(I) - 36.6 - (20 * FN LGT(F)) 920 N(I) = M(I) / 40 922 NN(I) = MM(I) / 20 925 IF NN(I) < N(I) THEN N(I) = NN(I) 930 D(I) = 10 ^ N(I) 933 D(I) = INT (D(I) * 100) / 100 935 NEXT I 940 GOTO 1100 1000 FOR I = 1 TO 6 STEP 1 1010 M(I) = Q(I) - 100.0 - (20 * FN LGT(F)) + (20 * FN LGT(H1)) + (10 * FN LGT(H2)) 1015 MM(I) = Q(I) - 36.6 - (20 * FN LGT(F)) 1020 N(I) = M(I) / 40 1023 NN(I) = MM(I) / 20 1025 IF NN(I) < N(I) THEN N(I) = NN(I) 1030 D(I) = 10 ^ N(I) 1033 D(I) = INT (D(I) * 100) / 100 1035 NEXT I 1040 GOTO 1100 1100 CLS 1101 PRINT "ษอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออป" 1102 PRINT "บ VHF TERRESTRIAL PROPAGATION - MODULE 3 บ" 1103 PRINT "ศอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออออผ" 1110 PRINT 1115 PRINT 1120 PRINT 1125 PRINT 1130 REM LINES RESERVED 1200 PRINT " RELIABILITY / COMMUNICATIONS RANGE" 1205 PRINT "__________________________________________________" 1220 PRINT 1225 PRINT 1245 PRINT 1246 PRINT 1250 PRINT USING "RANGE WITH 50% RELIABILITY IS ###.# MILES ";D(1) 1260 PRINT USING "RANGE WITH 75% RELIABILITY IS ###.# MILES ";D(2) 1270 PRINT USING "RANGE WITH 90% RELIABILITY IS ###.# MILES ";D(3) 1280 PRINT USING "RANGE WITH 95% RELIABILITY IS ###.# MILES ";D(4) 1290 PRINT USING "RANGE WITH 99% RELIABILITY IS ###.# MILES ";D(5) 1300 PRINT USING "RANGE WITH 99_.9% RELIABILITY IS ###.# MILES ";D(6) 1310 PRINT 1320 PRINT "CHOOSE:" 1330 PRINT " 1) MORE CALCULATIONS" 1340 PRINT " 2) QUIT" 1345 PRINT " ENTER CHOICE (1 or 2): "; 1350 INPUT CX 1360 IF CX = 1 THEN GOTO MENU ELSE GOTO ENDING ENDING: CLS PRINT LOCATE 10,25 PRINT "๐๐๐ PROGRAM COMPLETED ๐๐๐" END 'ษอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออป 'บ Program Authorship Notice บ 'บ ๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐๐ บ 'บ บ 'บ Jacob Z. Schanker, P.E. บ 'บ บ 'บ Scientific Radio Systems, Inc. บ 'บ 367 Orchard Street บ 'บ Rochester, NY 14606 บ 'บ (716) 235-2040 บ 'บ บ 'บ Last revised: March 1988 บ 'บ บ 'ศอออออออออออออออออออออออออออออออออออออออออออออออออออออออออออผ