HANI) w nrrii am) rRASSMissiox I'EKiouMAycE vn 



Table IV. Miiiinium Bund Widths and Corresponding Tower Reciuiremenls for 



Message Tj'pe Circuits 

 Table V. Minimum Band Widths and Corresponding Power Requirements for 



Program Type Circuits 



IV. FREQUENCY OCCUPANCY TABLES FOR RADIO RELAY 



\. Antenna Characteristics 



Fig. 2\. Directional selectivity of microwave antenna 



Fig. 22. Simplified route patterns for study of selectivity required in congested 



localities 

 Table VL True Frequency Occupancy of Various Message Grade Radio Relay 



Systems for Congested Routes 

 Table VIL True Frequency Occupancy of Various Program Type Radio Relay 



Systems for Congested Routes 

 2. Conclusions as to Radio 

 Table VIIL Comparisons of Band Width and Frequency Occupancy for Systems 



of Equal Ruggedness 



V. MORE ABOUT THE NON-SIMULTANEOUS LOAD ADVANTAGE 



Fig. 23. Theoretical possibilities of exploiting non-simultaneous load advantage 

 by an elastic PLM-AM system 



VI. OVERLOAD DISTORTION AND NOISE THRESHOLD 



Fig. 24. Noise threshold and overload ceiling in frequency divided PCM groups 

 Fig. 25. Overload characteristics of multirepeater systems 



VII. PULSES, SPECTRA, AND FILTERS 



Fig. 26. Typical pulses and their spectra 



1. Pulses for PPM 



2. Pulses for PAM 



3. Pulses for PCM 



4. Optimum Distribution of Selectivity Between Transmitting and Receiving 



Filters 

 Fig. 27. Crossfire between frequency divided pulse groups 



5. Delay Line Balancing 



VIIL TRANSMISSION OVER METALLIC CIRCUITS 



Fig. 28. Variation of circuit length with number of repeater sections in an AM 



system with fixed power capacity and noise figure 

 Fig. 29. Optimum number of repeater sections and maximum circuit length for 



metallic AM system with fixed power capacity and noise figure^ 

 Fig. 30. Optimum number of repeater sections and maximum circuit length for 



metallic FM system with limiting only at end of system 

 Fig. 3L Optimum number of repeater sections and maximum circuit length for 



metallic PPM-AM system with reshaping at every repeater 

 Fig. 32. Optimum number of repeater sections and maximum circuit length for 



metallic FM system with limiting at every repeater 

 Fig. 33. Relation between circuit length, power, and number of repeaters m radio 



relay systems 



IX. CONCLUSIONS 

 X. APPENDICES 



Appendix I. Noise in PCM Circuits 



Fig. 34. Stepping and sampling an audio wave 



Fig. 3.5. Variation of quantizing noise with samp'ing frequency 



Appendix II. Interference Between Two Frequency Modulated Waves 



Fig. 36. Geometric solution for resultant phase of two frequency modulated 

 waves 



Appendix III. PCM for Band Width Reduction 



