4-Meter-Band
As a 4 - meter band (80 MHz band ) is called the frequency range of 68 to 87.5 MHz band, which is used by operating, the BOS radio and the Bundeswehr. Other applications are in train radio in energy utility and forestry.
The frequency range is used mainly in the frequency modulation (FM).
In the territory of the former Soviet Union, part of the 4-meter band was also used as a normal broadcast band (see OIRT band).
4-meter amateur band
In some countries, small areas were released at the 4- meter band for radio amateurs. For use in England and the Netherlands the range from 70 to 70.5 MHz radio amateurs.
The band plan is as follows:
- 70.085 PSK31 center of activity
- 70.185 Cross -spectrum activity center
- 70,200 SSB / CW calling frequency
- 70.260 AM / FM calling frequency
- 70,300 RTTY/FAX-Anruf- and operating frequency
- 70.3125 digital modes
- 70.325 digital modes
- 70.3375 digital modes
- 70.350 digital modes
- 70.3625 digital modes
- 70.375 FM simplex
- 70.3785 Internet voice gateways
- 70.400 FM simplex
- 70.4125 Internet voice gateways
- 70.425 FM simplex
- 70.4375 digital modes
- 70.450 FM calling frequency
- 70.4625 digital modes
- 70.475 FM simplex
- 70.4875 digital modes
4- meter band Bundeswehr
In the army of the 4 - m radio inland from non-combat units is used, for example, from the Bundeswehr service centers, paramedics or fire department of the Bundeswehr. The devices used are modifications of the BOS devices. They have the same device names ( FuG -7, FuG -8 etc ), but use different frequencies according to the above table. Since the frequency bands of the 20 - kHz devices partially overlap, the BOS - channels are shifted by 5 kHz in the grid.
4-meter -BOS - band
The frequency spectrum extends from 74.215 to 87.255 MHz, which also takes place analogous to the 2- meter band a subdivision into an upper band and a lower band.
The frequencies are distributed to 164 switchable channels ( 347-510 ), of which the channels are operated 377-396 exclusively in the upper band, channel 510 (channel for automotive marches ) exclusively in the low band. The frequency offset ( duplex spacing ) between the upper and lower band is 9.8 MHz here. As a rule, sparking the relay station in the upper band, the vehicles and other units in the low band. For use with a relay station is the type of traffic oncoming traffic, use the type of traffic exchange traffic for direct connections between two vehicles. Explanation of the different radio modes and forms can be found in the article radiotelephony.
Radios for the 4- meter band are most firmly installed in the vehicle ( FuG 7b - FuG 8a and b), but also handheld radios (eg, FuG 13, FuG 13a, FuG 13b) it can be used.
The radio call at the 4- meter band differ from those of the 2 -meter band, further information refer to the article on bad radio.