General Instrument C6M-II, Руководство по установке

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C6M-II Installation Manual
Appendix E
Application Notes
C6-LPF600
This application note is to assist you in the operation of the C6M in headends operating above
600 MHz.
Summary
The C6M incorporates a dual high IF conversion technique that minimizes spurious and
distortion products within the 50 to 600 MHz operating bandwidth of the C6M. The high IF
local oscillator, which is used to downconvert the high IF to the desired output RF carriers,
operates above 600 MHz. This local oscillator frequency may be present at the C6M RF output
and may cause interference with analog and digital channels, or data carriers operating above
600 MHz.
To minimize this potential problem, install a C6-LPF600. The C6-LPF600 is a high
performance, low-pass filter (10 to 600 MHz) that may be used to attenuate spurious carriers
occurring at 600 MHz and above frequencies. The specifications on this filter are included with
this application note.
Discussion
The C6-LPF600 (GI Part No. 928-363-000) is installed either at the RF output of the C6M, or
may be installed at the C6M RF combined output before the insertion of channels operating
above 600 MHz.
Typical installations with the C6M and the C6M-II are displayed below.
Figure E-1
Typical installations of C6-LPF600