MRC DRS4000, Руководство пользователя и техническое руководство

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Installation 4-7 DRS4000 Receiver User and Technical Manual
be required. Contact MRC for specific cable types and lengths
to use in your application.
If you do not connect the antennas directly to the
downconverters, you will have to fabricate your own antenna
mounting bracket. Remember that the distance between each
pair of antennas is critical for optimum performance.
4.9.3 Aligning Omnidirectional Antennas
For applications using omnidirectional antennas, proper
installation of the antennas will result in optimum performance. In
all installations, the minimum distance between any two
antennas is important.
Table 4-1 provides minimum separation distances for several
frequency ranges available with the DRS4000 Receiver. This is
the minimum recommended distance between any two
antennas.
Table 4-1: Minimum Separation Distances for Antennas
Frequency
Band
(Reference
Freq.) MHz
Recommended
Separation
(cm) (inch)
Adjustment by 1/4
Wavelength
(mm) (inch)
1700 to 1850
(1700) 52.94 20.84 44.12 1.74
1900 to 2200
(1900) 47.37 18.65 39.47 1.55
2200 to 2500
(2200) 40.91 16.11 34.09 1.34
2300 to 2700
(2300) 39.13 15.41 32.61 1.28
4400 to 4700
(4400) 20.45 8.05 17.05 0.67
Also, the antennas must be plumb (vertical) for best
performance. The relative height of the antennas should be the
same but is not critical. For example, if the antennas are
mounted on a tower or a mast, the antennas must be mounted
vertically (all parallel to each other) and mounted at a similar
height on the tower or mast.
The separation distance between the antennas must be
measured from the center lines of the antennas as shown in
Figure 4-3 on page 4-8 . You should initially install the antennas
at the recommended minimum separation distance. If necessary,
increase the distance by quarter wavelengths.
4800 to 5000
(4800) 18.75 7.38 15.63 0.62
6400 to 6500
(6400) 14.06 5.54 11.72 0.46
Frequency
Band
(Reference
Freq.) MHz
Recommended
Separation
(cm) (inch)
Adjustment by 1/4
Wavelength
(mm) (inch)