2 meter tape

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The 2 meter band ( 2 m band ) is the frequency band around 150 MHz.

Classically, it means amateur radio (144 MHz to 146 MHz, in America, Oceania and parts of Asia 144 MHz to 148 MHz), but the term is also used for other radio services, in particular to switch between different possible bands ( 70 cm , 2 m, 4 m and 8 m). These are the BOS radio (165 MHz to 174 MHz) and the company radio ( 146 MHz to 174 MHz).

In addition to handheld radios , fixed and vehicle built-in devices are common.

Propagation conditions

The 2 meter band is part of the VHF spectrum and is widely used for local communication. The range of fixed radio stations is heavily dependent on the individual equipment and operating modes used. For simple stations with omnidirectional antennas it is up to 50 km, that of a handheld radio about 5 to 10 km. This distance can be increased by using relay stations . Well-equipped stations have directional antennas and transmit powers of up to several hundred watts (Germany: up to 750 W). This allows regularly km over the bump up to 300 km with the help of reflections on aircraft up to 800, via meteor to over 2,000 km and Moon Bounce are km bridged up to 18,000. Narrowband modes such as telegraphy or FSK441 or JT65 (both digital) are preferably used, but under favorable circumstances single sideband modulation (SSB) is also used. In the case of special propagation conditions (e.g. inversion weather conditions , Sporadic-E ), brief overreaches of several hundred to sometimes several thousand kilometers occur in the 2 m band.

Antennas

Example of a 2 meter double quad yagi

The 2-meter tape allows short and compact antennas to be used; Directional antennas (especially yagi and quad antennas ) can also be built with little effort. For handheld radios, helical rubber antennas (" rubber sausage ", electrically shortened quarter-wave radiators) are often used, with losses in radiation being accepted in favor of handiness.

2 meter amateur radio band

Commercial amateur radio

The 2-meter amateur radio band extends from 144 to 146 MHz (ITU region 1: Europe, Russia, Africa); in the rest of the world (ITU regions 2 and 3, e.g. in the USA ) it ranges from 144 to 148 MHz.

In addition to regional amateur radio relays , radio amateurs have built and launched amateur radio satellites through the AMSAT organization to cover great distances . This enables radio connections to be made anywhere in the world. Alternatively, you can use the moon as a reflector. This operating mode is known as earth-moon-earth radio operation and places high demands on the transmitter and receiver systems.

In order to distribute the different operating modes evenly on the 2 m band and to keep the mutual influences low, an international band plan was created and thus certain segments of the 2 m band were assigned to the individual operating modes. For example, there is a frequency of 144.800 MHz for APRS and a range in the 145.8 to 146 MHz range for amateur radio satellites.

Band plan

Frequency range use
144.000-144.150 MHz CW
144.150-144.400 MHz CW and SSB (international calling frequency SSB: 144.300 MHz)
144.400-144.490 MHz CW beacons (no transmission)
144.500-144.794 MHz all operating modes
144.800-144.9625 MHz Digital operating modes
  • 144.800 MHz for APRS
  • Packet radio channels have a channel spacing of 12.5 kHz
144.975-145.1875 MHz FM relay input (+600 kHz shift)
  • FM relay channels have a channel spacing of 12.5 kHz
  • FM relay outputs are coupled to their corresponding inputs
145.2125-145.5625 MHz FM simplex
  • Channel spacing: 12.5 kHz
145.575-145.7875 MHz FM relay output (-600 kHz shift)
  • FM relay channels have a channel spacing of 12.5 kHz
  • FM relay inputs are coupled to their corresponding outputs
145.800-146.000 MHz Amateur radio satellites

2 meter BOS tape

Like the 4 m band , the 2 m band is also divided into different channels, which in turn are divided into an upper and a lower band . Operation on the voice radio channels (channels 201 to 292) of the total of 117 channels is in most cases intercom in the sub-band. Channels 101 to 125 are reserved for relay controls and digital alarms .

The frequency spectrum in the sub-band extends from 165.210 MHz to 169.380 MHz with a channel spacing of 20 kHz; the upper band is offset upwards by 4.6 MHz per channel.

The paging names in the 2 m band differ in part from those in the 4 m band. For more information, see the article on BOS radio .

Band plan

Frequency range use
165.210-169.380 MHz BOS radio sub-band
169.810-173.980 MHz BOS radio upper strap

VHF marine radio

Frequency range use
156.025-162.0 MHz VHF radio
161.975 MHz and 162.025 MHz AIS

Former use

  • Between 1958 and 1994 the first analog mobile phone networks A-Netz and B-Netz were operated in Germany between a total of 148 MHz and 174 MHz.

Web links

Individual evidence

  1. ^ German Amateur Radio Club (ed.): Band plans . www.darc.de ( Memento of February 16, 2009 in the Internet Archive ), accessed on April 2, 2010.
  2. ↑ Radio amateur: FM radio at 2 m and 70 cm - channel list (PDF; 848 kB)