Table 5
Betty’s Chances of Hearing Amelia on a Harmonic
Probability (in percent, or chances out of 100) that the required Signal-to-Noise Ratio
would occur on 5 out of 20 days
Date,
Day,
SSN*
  
15525 kHz
18630 kHz
21735 kHz
24840 kHz
Xmtr Power Out (watts)
Xmtr Power Out (watts)
Xmtr Power Out (watts)
Xmtr Power Out (watts)
Hour†
50
5
1
0.5
0.1
50
5
1
0.5
0.1
50
5
1
0.5
0.1
50
5
1
0.5
0.1
July 2
Fri
91
1500
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
5
1
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
4
1
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
July 3
Sat
74
1500
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
2
1
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
2
0
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
2
0
0
0
0
July 4
Sun
65
1500
0
0
0
0
0
0
0
0
0
0
3
1
0
0
0
1
0
0
0
0
1600
0
0
0
0
0
1
0
0
0
0
2
0
0
0
0
1
0
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
July 5
Mon
91
1500
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
4
1
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
4
1
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
July 6
Tue
108
1500
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
5
1
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5
1
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
Jul 7
Wed
143
1500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Jul 8
Thur
185
1500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
July 9
Fri
181
1500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1600
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1700
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Notes
* SSN = sunspot number for the date indicated, included to illustrate daily changes in propagation conditions.
† Hour = local hour at St. Petersburg, e.g., the 1500 hour extends from 1500 to 1600.