SAMPLE COMPUTATIONS 



161 



Figure 4.53. 1 ,046-Mc/s fields for the night of June 21-22, 1952, at Kendrick, Karval, 



and Haswell, Colo. 



and hence 



hi for a 100-m duct under maximum spring ducting conditions = 92.3 m, 

 hi for a 200-m duct under maximum spring ducting conditions = 166.0 m, 

 hi for a 100-m duct under mean spring ducting conditions = 96.0 m, 

 hi for a 200-m duct under mean spring ducting conditions = 187.0 m, 

 hi for a 100-m duct under minimum spring ducting conditions = 99.0 m, 



and 



hi for a 200-m duct under minimum spring ducting conditions = 199.0 m. 

 Figures 4.47 and 4.48 will be used to determine /i2 from the total 

 distance, d. The distance to be used is obtained by subtracting the dis- 

 tance, do, from the desired distance. For the 100-m duct, do = 83 km and 



d = 90 - 83 = 7 km. 



Likewise for the 200-m duct, do = 72 km and 



rf = 90 - 72 = 18 km. 



Thus it is found that for the model assumed: 



(a) /i2 for the 100-m duct height case will always be 3 m, 



(b) /i2 for the 200-m duct height case will always be 18 m. 

 Since from (4.40) 



hi < loss region < /i^ + /12. 



