User Manual Part 2

Installation 6-10MTX5000 User and Technical Manual
MRC strongly recommends using a 4-conductor, 16 AWG
wire combination for DC power that supports Standard and
High Power ODUs.
Specifically, wiring should be in accordance with Table 6-3 for
Standard ODU use and Table 6-4 on page 6-11 for High Power
ODU use.
MRC recommends that installations of the MTX5000 IDU and
ODU be carefully considered, especially where the DC power to
the ODU is concerned. All ODUs used to support digital
(COFDM) transmission require higher linearity and therefore
require more input current to the power amplifiers to achieve
acceptable levels of Modulation Error Ratio (MER) performance.
This is especially true of the optional High Power ODUs.
For new Nycoil installations where the cable length is 160 feet
(48.8 M) or less, MRC suggests two 16 AWG multi-strand
conductors in parallel for both power and return. In a new
installation, this is less likely an issue, however for an existing
installation, other alternatives may be more appropriate.
The following factory recommendation applies to existing
installations. At the very least, all cabling in an existing
installation must be inspected to ensure that no corrosion or
broken strands are present, especially if new conductors are not
used.
The acceptable cable lengths for existing Standard power ODU
installations, or alternatives to the recommendation, are provided
in Table 6-3 as a function of mast height. The recommended
lengths are end-to-end cable length vs. mast height.
The acceptable cable lengths for high power ODU installations,
or alternatives to the recommendation, are provided in Table 6-4
on page 6-11 as a function of mast height. The recommended
lengths are end-to-end cable length vs. mast height.
Table 6-3: Existing Installation Cable Lengths - Standard
Power ODU
Mast Height
RF
Connector
Type
Minimum
Wiring for
Power and
Return
Assumed
Maximum
Cable
Length
< 58 Feet Triax Triax 160 ft.
(48.8.0 M)
< 58 Feet N 4 Conductors
of 16 AWG (2
Power, 2
Return)
160 ft.
(48.8 M)
< 58 Feet N 4 Conductors
of 20 AWG (2
Power, 2
Return)
140 ft.
(42.7 M)
< 58 Feet N 7 Conductors
of 20 AWG (4
Power, 3
Return)
160 ft.
(48.8 M)
< 58 Feet TNC 8 Conductors
of 20 AWG (4
Power, 4
Return)
160 ft.
(48.8 M)