Table 2
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 2 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
7
2
1
0
0
25
16
11
9
6
1600
0
0
0
0
0
0
0
0
0
0
8
2
1
0
0
23
14
9
7
4
1700
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
11
4
1
1
0
July 3
Sat
74
1500
0
0
0
0
0
0
0
0
0
0
13
6
3
2
1
20
13
9
7
5
1600
0
0
0
0
0
0
0
0
0
0
15
6
3
2
1
18
11
7
6
4
1700
1
0
0
0
0
0
0
0
0
0
3
2
0
0
0
13
4
2
1
0
July 4
Sun
65
1500
0
0
0
0
0
0
0
0
0
0
19
10
6
5
3
15
9
6
5
3
1600
0
0
0
0
0
9
2
1
0
0
17
8
4
3
2
16
10
6
5
3
1700
0
0
0
0
0
0
0
0
0
0
5
1
0
0
0
11
4
2
1
0
July 5
Mon
91
1500
0
0
0
0
0
0
0
0
0
0
8
2
1
1
0
24
15
10
9
6
1600
0
0
0
0
0
0
0
0
0
0
8
2
1
1
0
23
14
9
7
4
1700
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
11
4
1
1
0
July 6
Tue
108
1500
0
0
0
0
0
16
9
6
5
3
5
1
0
0
0
25
15
9
8
4
1600
0
0
0
0
0
0
0
0
0
0
3
1
0
0
0
24
13
8
6
3
1700
0
0
0
0
0
0
0
0
0
0
4
1
0
0
0
9
2
1
0
0
Jul 7
Wed
143
1500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8
2
1
1
0
1600
0
0
0
0
0
0
0
0
0
0
5
1
0
0
0
6
1
0
0
0
1700
0
0
0
0
0
5
2
1
1
1
0
0
0
0
0
3
1
0
0
0
Jul 8
Thur
185
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
2
1
3
2
1
0
0
0
0
0
1
0
0
0
0
July 9
Fri
181
1500
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
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
1
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.