---
kind: "section"
citation: "47 C.F.R. § 73.190"
title: "47"
number: "73.190"
heading: "Engineering charts and related formulas."
url: "https://uscodex.org/cfr/47/73.190"
---

# §73.190. Engineering charts and related formulas.

- (a) **This section consists of the following Figures—** 2, r3, 5, 6a, 7, 8, 9, 10, 11, 12, and 13. Additionally, formulas that are directly related to graphs are included.
- (b) **Formula 1 is used for calculation of 50% skywave field strength values.**
- (c) **Formula 2 is used for calculation of 10% skywave field strength values.**
- (d) **Figure 6a depicts angles of departure versus transmission range.** These angles may also be computed using the following formulas:
- (e) In the event of disagreement between computed values using the formulas shown above and values obtained directly from the figures, the computed values will control.

## Notes

### Amendments

[28 FR 13574, Dec. 14, 1963, as amended at 30 FR 12720, Oct. 6, 1965; 33 FR 15420, Oct. 17, 1968; 48 FR 42959, Sept. 20, 1983; 49 FR 43963, Nov. 1, 1984; 50 FR 18844, May 2, 1985; 51 FR 4753, Feb. 7, 1986; 52 FR 36879, Oct. 1, 1987; 56 FR 64869, Dec. 12, 1991]

### Authority

Authority: 47 U.S.C. 154, 155, 301, 303, 307, 309, 310, 334, 336, 339.

### Amendments

[28 FR 13574, Dec. 14, 1963, as amended at 30 FR 12720, Oct. 6, 1965; 33 FR 15420, Oct. 17, 1968; 48 FR 42959, Sept. 20, 1983; 49 FR 43963, Nov. 1, 1984; 50 FR 18844, May 2, 1985; 51 FR 4753, Feb. 7, 1986; 52 FR 36879, Oct. 1, 1987; 56 FR 64869, Dec. 12, 1991]