PMR446

PMR radio (short for Private Mobile Radio ), also referred to as PMR 446 is a relatively new citizens' band radio application, which is allocated from 446.000 to 446.100 MHz UHF frequency range. PMR is the European counterpart to the American FRS, short for Family Radio Service.

Frequency range

The frequency range is divided into 8 channels at 12.5 kHz channel spacing. In order to utilize the available frequency range 446.0 to 446.1 MHz, as effectively as possible, this pattern was compared to the normal arrangement ( in which a channel, the frequency would have received 446.0 MHz) to 6.25 kHz (ie, a half of the channel width) moved.

All frequencies 446.000 to 446.100 have the channel spacing of 6.25 kHz, the frequencies 446.100 to 446.2000 ( DMR446 ) have in the analog domain the channel spacing of 12.5 and in the digital area of 6.25 kHz.

In addition to these eight channels, user groups can be formed by the use of pilot tone, which interfere with each other less frequently. In general, for CTCSS ( Continuous Tone Coded Squelch or Continuous Tone Coded Subaudio Squelch System), an analogous process or digital squelch Digital Coded Squelch (DCS ) are used. CTCSS is to be noted that only the received signal is blocked. When sending the CTCSS tone is emitted in addition to the language, and the receiving radio opens in matching the encoding CTCSS squelch. Did you set the radio, say, channel 4 and CTCSS 13, you can hear only the stations that also emit the same CTCSS tone. All users that Channel 4 without CTCSS Subcodierung, or CTCSS have set 0 can overhear the transmissions, however, will not they heard of the others. DCS-/CTCSS-Kodierungen should not be confused with " eavesdropping ," for he who CTCSS 0 is on the " main channel ", stop all shipments of " subchannels " with. This coding thus serve only to hide other users on the same channel.

Range

The units may in Germany a transmission power of up to 500 mW (ERP ) have, what a range of about 5 km allows for very good conditions. Only devices with fixed tailed antenna ( "integrated antenna " ) allowed. Most devices are portable radios, in some cases there are also state of devices in the design panel. With interference from other spectrum users to be expected, since the frequency range is not allocated exclusively (see Federal Network Agency Const 78/2003 ).

The maximum range of a PMR device depends strongly on the environment. Under optimum conditions, can get up to 10 km over bridge (eg, between two mountain peaks ). In heavily built-up areas often leads less than a kilometer wide. In forests, the range usually is between 2 and 3 km. Most hand-held devices ( mainly from the lower price segment ) create in built-up areas only about 200 m.

Since 2006 are above those of PMR446 additional frequencies available on which digital voice transmission is required under the same conditions of use as for PMR446. The range of this digital broadcasting Every man can be different under certain conditions of the analog variant with the same transmission power. (See also: DMR446 )

Gateways

Recently, it is possible to cover long distances via the Internet via RF gateways. For a program (eg eQSO, FRN, Teamspeak or Mumble ) will be established, which transmits the received audio signals from CB radios, PMR, Freenet or LPD-/SRD-Funkgerät the Internet and at a different location a CB radio, PMR, Freenet or LPD / SRD radio feeds again. In amateur radio, there are already more similar to the working EchoLink network. (see also: VoIP)

Terms of Use

In contrast to the SRD operation of PMR is permitted in most European countries. In Germany the frequency allocation PMR -446 is valid until 31 December 2022.

Citizens' band radio in other countries: frequency ranges for everyone radio applications are often only awarded in national or European uniform. Who wants to use its devices overseas, you should be informed beforehand whether you can use the equipment or frequencies there for everyone - radio applications (PMR ). Conversely, the same applies abroad ( on holiday, on the Internet ) purchases PMR devices that are not approved in Germany in part and may not be used, because they use different frequencies. Information about the speed limits in Germany frequencies are obtained from the Federal Network Agency ( FNA ).