SpectrumWiki

Radio spectrum allocations

Look up a frequency or a range.

Examples: 88.5 MHz, 1350–1430 MHz, 2.4 GHz

7.299999 MHz (7,299,999 Hz)

ITU Region 1 Allocations

7.2 – 7.3 MHz

BROADCASTING

ITU Region 2 Allocations

7.2 – 7.3 MHz

AMATEUR

5.142

ITU Region 3 Allocations

7.2 – 7.3 MHz

BROADCASTING

Footnotes

  • 5.142
  • US142   In the bands 7.2-7.3 and 7.4-7.45 MHz, the following provisions shall apply:

        (a) In the U.S. Pacific insular areas located in Region 3 (see 47 CFR 2.105(a), note 3), the bands 7.2-7.3 and 7.4-7.45 MHz are alternatively allocated to the broadcasting service on a primary basis. Use of this allocation is restricted to international broadcast stations that transmit to geographical zones and areas of reception in Region 1 or Region 3.

        (b) The    use of the band 7.2-7.3 MHz in Region 2 by the amateur service shall not impose constraints on the broadcasting service intended for use within Region 1 and Region 3.

  • 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
6.685–8.815 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).

Amateur Radio 40 m Band

Current Use
7–7.3 MHz Amateur Radio 40 m band (ITU Region 2)
According to the ITU, "the 7 MHz band is heavily used 24 hours each day. During daylight hours, the band carries the bulk of amateur sky wave communication over distances of less than 1 300 km."

The band is commonly referred to as the 40 m band, because of its approximate wavelength.

In ITU Regions 1 & 3, the band 7200 - 7300 kHz is allocated to broadcasting instead of amateur radio. The high power, long distance broadcast signals often interfere with Region 2 amateur radio operations in this band segment, especially at night.

In the U.S., the ARRL has adopted the following band plan. The plan may apply in other countries as well. Following the band plan are the band segments that are authorized for the specified U.S. licensee classes.

ARRL BAND PLAN:






Frequency (kHz)Use
7040RTTY/Data DX
7080-7125RTTY/Data
7171SSTV
7290AM calling frequency


EXTRA:




Range (kHz)Authorized Use(s)
7000-7125RTTY and data
7125-7300Phone and image


ADVANCED:




Range (kHz)Authorized Use(s)
7025-7125RTTY and data
7125-7300Phone and image


GENERAL:




Range (kHz)Authorized Use(s)
7025-7125RTTY and data
7175-7300Phone and image


TECHNICIAN AND NOVICE (200 W MAX):



Range (kHz)Authorized Use(s)
7025-7125CW only

Shortwave Broadcasting

Current Use
7.2–7.45 MHz 41 m band (shared with amateur radio 40 m band)
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.