Allocations

 
U.S. Non-Federal-Government Allocations
3.5 - 4 MHz
AMATEUR

FCC Rule Parts:
Amateur Radio (97)

U.S. Federal Government Allocations
3.5 - 4 MHz


ITU Region 1 Allocations
3.5 - 3.8 MHz
AMATEUR
FIXED
MOBILE except aeronautical mobile


ITU Region 2 Allocations
3.5 - 3.75 MHz
AMATEUR


ITU Region 3 Allocations
3.5 - 3.9 MHz
AMATEUR
FIXED
MOBILE


SpectrumWiki


Footnotes


5.119 Additional allocation: in Honduras, Mexico and Peru, the band 3500-3750 kHz is also allocated to the fixed and mobile services on a primary basis. (WRC-07)

5.92 Some countries of Region 1 use radiodetermination systems in the bands 1606.5-1625 kHz, 1635-1800 kHz, 1850-2160 kHz, 2194-2300 kHz, 2502-2850 kHz and 3500-3800 kHz, subject to agreement obtained under No. 9.21. The radiated mean power of these stations shall not exceed 50 W.

US340 The band 2-30 MHz is available on a non-interference basis to Federal and non-Federal maritime and aeronautical stations for the purposes of measuring the quality of reception on radio channels. See 47 CFR 87.149 for the list of protected frequencies and bands within this frequency range. Actual communications shall be limited to those frequencies specifically allocated to the maritime mobile and aeronautical mobile services.

SpectrumWiki

 
Amateur Radio 80 m Band
Shortwave Broadcasting
Access Broadband over Power Line (Access BPL)


Related Documents, Links, and Multimedia:
FCC Proceeding (8)
Band Plan (2)

Engineering Data

Lower Frequency Center Frequency Upper Frequency
Frequency 3500 kHz 3750 kHz 4000 kHz
Wavelength 85.7 m 79.9 m 74.9 m
Band designator(s) HF HF HF
Isotropic collecting area 583.8 m2 508.6 m2 447.0 m2
Free space loss (1 m) N/A (near field) N/A (near field) N/A (near field)
Free space loss (1 km) 43.3 dB 43.9 dB 44.3 dB
Free space loss (10 km) 63.3 dB 63.9 dB 64.3 dB
Free space loss (100 km) 83.3 dB 83.9 dB 84.3 dB
Free space loss (1000 km) 103.3 dB 103.9 dB 104.3 dB
Free space loss
(35,786 km = GEO orbit)
134.4 dB 135.0 dB 135.3 dB
Free space loss (378,370 km = Moon) 154.9 dB 155.5 dB 155.8 dB