5.134
5.146 Additional allocation: frequencies in the bands 9 400-9 500 kHz, 11 600-11 650 kHz, 12 050-12 100 kHz, 15 600-15 800 kHz, 17 480-17 550 kHz and 18 900-19 020 kHz may be used by stations in the fixed service, communicating only within the boundary of the country in which they are located, on condition that harmful interference is not caused to the broadcasting service. When using frequencies in the fixed service, administrations are urged to use the minimum power required and to take account of the seasonal use of frequencies by the broadcasting service published in accordance with the Radio Regulations. (WRC-07)

US136 The following provisions shall apply in eight HF bands that are allocated to the broadcasting service (HFBC) on a primary basis in all Regions.

(a) In Alaska, the assigned frequency band 7368.48-7371.32 kHz is allocated exclusively to the fixed service (FS) on a primary basis for non-Federal use in accordance with 47 CFR 80.387.

(b) On the condition that harmful interference is not caused to the broadcasting service (NIB operations), Federal and non-Federal stations that communicate wholly within the United States and its insular areas may operate as specified herein. All such stations must take account of the seasonal use of frequencies by the broadcasting service published in accordance with Article 12 of the ITU Radio Regulations and are limited to the minimum power needed for reliable communications.

(1) Federal stations. Frequencies in the 13 HF bands/sub-bands listed in the table below (HF NIB Bands) may be authorized to Federal stations in the FS. In the bands 5.9-5.95, 7.3-7.4, 13.57-13.6, and 13.80-13.87 MHz (6, 7, 13.6, and 13.8 MHz bands), frequencies may also be authorized to Federal stations in the mobile except aeronautical mobile route (R) service (MS except AM(R)S). Federal use of the bands 9.775-9.9, 11.65-11.7, and 11.975-12.05 MHz is restricted to stations in the FS that were authorized as of June 12, 2003, and each grandfathered station is restricted to a total radiated power of 24 dBW. In all other HF NIB Bands (*), new Federal stations may be authorized.

(2) Non-Federal stations. Non-Federal use of the HF NIB Bands is restricted to stations in the FS, land mobile service (LMS), and maritime mobile service (MMS) that were licensed prior to March 25, 2007, except that, in the sub-band 7.35-7.4 MHz, use is restricted to stations that were licensed prior to March 29, 2009.

NIB OPERATIONS IN EIGHT HFBC BANDS (MHZ)
HF NIB Band	Federal (*new stations permitted)	Non-Federal	HFBCBand
5.90-5.95 7.30-7.40	FS and MS except AM(R)S FS and MS except AM(R)S	MMS FS, LMS and MMS	5.90-6.20 7.30-7.40
9.40-9.50 9.775-9.90	*9 MHz: FS FS (Grandfathered, restricted to 24 dBW)	FS and LMS	9.40-9.90
11.60-11.65 11.65-11.70 11.975-12.05 12.05-12.10	11 MHz: FS FS (Grandfathered, restricted to 24 dBW) FS (Grandfathered, restricted to 24 dBW 12 MHz: FS	FS	11.60-12.10
13.57-13.60 13.80-13.87	FS and MS except AM(R)S FS and MS except AM(R)S	MMS MMS	13.57-13.87
15.60-15.80 17.48-17.55 18.90-19.02	15 MHz: FS 17 MHz: FS *19 MHz: FS	FS … MMS	15.10-15.80 17.48-17.90 18.90-19.02

Note: Non-Federal stations may continue to operate in nine HF NIB Bands as follows: (i) In the 6, 7, 13.6, 13.8, and 19 MHz bands, stations in the MMS; (ii) In the 7 and 9 MHz bands, stations in the FS and LMS; and (iii) In the 11, 12, and 15 MHz band, stations in the FS.

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.

Wiki entries

Access Broadband over Power Line (Access BPL)

Current Use 17.97–21.924 MHz Access BPL

According to the FCC's definition, Access BPL is "a carrier current system installed and operated on an electric utility service as an unintentional radiator that sends radio frequency energy on frequencies between 1.705 MHz and 80 MHz over medium voltage lines or over low voltage lines to provide broadband communications and is located on the supply side of the utility service’s points of interconnection with customer premises. Access BPL does not include power line carrier systems as defined in § 15.3(t) or In-House BPL as defined in § 15.3(gg)."

Low voltage lines are defined as lines carrying, for example, 240/120 volts from a distribution transformer to a customer's premises. Medium voltage lines carry between 1,000 and 40,000 volts from a power substation to neighborhoods, and may be overhead or underground.

Access BPL is an unlicensed service operated under Subpart G of Part 15 of the FCC's rules. Radiated emission limits from medium voltage lines in the 1.705-30 MHz range must not exceed the limits in 47 CFR 15.209, and those from 30-80 MHz must not exceed the limits in 15.109(b). Systems that operate on low voltage lines must comply with 15.109(a) limits across the entire 1.705-80 MHz range.

When Access BPL systems must use notch filters to protect licensed services, the notch must be at least 25 dB below applicable Part 15 limits in the 1.705-30 MHz band, and at least 10 dB below the limits in the 30-80 MHz band.

There are 12 sub-bands in which Access BPL systems are not allowed to operate anywhere to protect aeronautical (land) stations and aircraft receivers. Those excluded bands are listed in 15.615(f), and are excluded in the list of Access BPL bands in this entry.

Access BPL systems are not allowed to operate within the sub-band 2173.5-2190.5 kHz within 1 km of coast station facilities listed in 47 CFR 15.615(f)(2)(i), to protect the internationally-recognized standard maritime calling frequency of 2182 kHz.

No Access BPL emissions are allowed in the 73.0-74.6 MHz radio astronomy band on overhead medium voltage lines within 65 km of the Very Large Array radio telescope in New Mexico (34 04 43.5N, 107 37 03.82W), or within 47 km of the VLA on underground power lines or overhead low voltage lines.

Access BPL operators must consult at least 30 days in advance when deploying systems near various FCC field offices, aeronautical and maritime stations, radar systems, radio astronomy stations, and research areas. Details are in 47 CFR 15.615(f)(3).

Shortwave Broadcasting

Current Use 18.9–19.02 MHz 15 m band (lightly used)

Various bands throughout the HF (and, technically, the MF) spectrum are used for what is commonly referred to as shortwave broadcasting. Most broadcasts use AM modulation, which can be received on inexpensive shortwave receivers. Within these bands, shortwave broadcasters use channels spaced every 5 kHz. Different broadcasters may use the same channel at different times, and schedules of shortwave broadcasts (which are coordinated through the International Telecommunication Union) change on a regular basis. Most shortwave broadcasts also use very high power, as much as 500,000 W, using very large antenna arrays.

Because many broadcasts are sent through relay stations, the identity of the broadcaster does not necessarily tell you where the signal is coming from. For example, Radio Moscow is retransmitted from a relay station in Cuba, to provide a strong signal into North, Central, and South America.

Most shortwave bands are referred to by their approximate wavelength. For example, the 9400-9900 kHz band is referred to as the "31 meter band," because the wavelength is approximately 31 m.

The Website Short-Wave.info (linked below) can be used to identify shortwave stations broadcasting on specific frequencies at specific times, in a specified language.