CLUB 100 Library - 415/939-1246 BBS, 937-5039 NEWSLETTER, 932-8856 VOICE RF PATH CALCULATIONS by Steve Petit [73300,2217] 7-Sep-87 The formulas were taken from a training manual, LIVING IN A CROWDED WORLD, issued by General Electric Co., written by Mr. A.K. Guthrie. I'm not sure who wrote the program that put everything together. The program will calculate, in dBM, the signal strength at the receiver from a transmitter at a known distance. The calculations use the figures for a 1/2 wave dipole antenna. If you prefer the calculations to be in dBW, the formulas can be modified or I can upload the complete program. The answers are the same. The results can be saved to RAM, to DISK or displayed on the LCD. In any case, you will be asked at the end of the run if you want a "hard copy" which will print out the results on the printer. The program will prompt you all the way through the run to let you know the input to be made. You must know: Transmitter Power Out, Antenna gains, antenna system losses, distance between the transmitter and receiver, the receiver sensitivity and the system frequency. The program has subroutines to convert the transmitter power output to dBM or dBW and convert the receiver input voltage to the same dB value. You will go through these subroutines while entering the data. The program will step you through. After the dB value is entered, press to continue. When the Transmitter or Receiver location is asked for, the name of the site can be entered. The location can have a maximum of 10 letters. The site name will be on the final printout and will correspond to the data entered for that site. You will have to calculate the antenna line and connector losses separately. They will be entered in the antenna system losses. CAUTION: When entering the "antenna system losses" the figure MUST be preceded by a "-" minus sign or the loss will be considered a gain. If there is a 5 dB loss, enter -5. Before the final calculations are made, the data that was entered will be displayed to verify that it was entered correctly. If you made a mistake, continue on with the program and it will take you to the beginning again where the correct value can be entered. If everything went well, the results will be displayed when you . The results will show the free space loss, the signal level above the receiver threshold and the amount of signal at the receiver port in microvolts and dB. If you want to run another path and only change one or more of the parameters, stay in the program, the values you have entered are still there. Change the values you want and at the ones you want to remain the same. They will stay in the program.