![C-COR.net FlexNet E629 Скачать руководство пользователя страница 50](http://html.mh-extra.com/html/c-cor-net/flexnet-e629/flexnet-e629_equipment-manual_478218050.webp)
4-8
FlexNet
®
700 Series Line Extender
Rev F
4
Forward Balancing
Forward Balancing Requirements
Make sure that the following conditions are valid for the E7 Line Extender before you start to balance:
✔
The system map is marked with amplifier output levels for bandedge frequencies.
✔
Forward balancing carriers set at the proper levels are injected into the cable network from
the headend.
✔
One forward balancing carrier is available at a lower bandedge.
✔
One forward balancing carrier is available at a higher bandedge.
✔
Operating voltages are correct (refer to Section if necessary).
✔
All tap outlets, ends of feeder cables, and unused active RF ports are terminated with a 75
W
impedance.
✔
Unscrambled ALC carriers are injected into the system at the assigned frequency for the E7
Line Extender (if ALC is to be used).
✔
Preceding amplifiers have been properly balanced and provide the desired forward band
signals to the E7 Line Extender for forward balancing.
Forward Balancing Procedure
Refer to Figures 2.2 to 2.5 and Table 2.1 for control and accessory locations.
➤
To balance the forward path
1. Determine the System Forward High and Low Balancing Carrier Levels:
■
If bandedge carriers are used for balancing, copy the E7 Line Extender bandedge
carrier output levels from the system map to the Map Signal Information table on the
FlexNet® 700 Series Line Extender Data Sheet
located in Appendix E.
■
If other than the bandedge carriers are used for balancing, calculate the balancing
carrier levels (see
Calculating Balancing Carrier Levels
— page 4-5 if not already done).
Record these levels in the Map Signal Information table on the
located in Appendix E.
2. Temperature compensate the System Forward High and Low Balancing Carrier Levels.
a. Record the current air temperature on the
FlexNet® 700 Series Line Extender Data
b. Follow the procedure outlined in the following table.
CAUTION
: RF signal levels greater than +30dBmV @ 1 NTSC channel loading at the
hybrid can damage amplifier active components. Do not use test signal levels that will
be greater than 30dBmV at the hybrid (+30dBmV = +90dBµV).
Note
: System values are the recommended values shown on the system map. Measured
values are the signal levels actually measured at the amplifier.
Содержание FlexNet E629
Страница 2: ...Introduction fm Page 10 Monday April 1 2002 12 43 PM ...
Страница 16: ...1 8 FlexNet 700 Series Line Extender Rev F 1 ...
Страница 23: ...Rev F Physical Identification 2 7 2 Figure 2 6 E629 Line Extender 19 4 5 3 21 17 20 14 13 13 16 ...
Страница 26: ...2 10 FlexNet 700 Series Line Extender Rev F 2 ...
Страница 64: ...4 22 FlexNet 700 Series Line Extender Rev F 4 ...
Страница 82: ...A 6 FlexNet 700 Series Line Extender Rev F A ...
Страница 88: ...B 6 FlexNet 700 Series Line Extender Rev F B ...
Страница 102: ...C 14 FlexNet 700 Series Line Extender Rev F C ...
Страница 104: ...D 2 FlexNet 700 Series Line Extender Rev F D ...
Страница 110: ...Index 4 Rev F ...
Страница 111: ...Introduction fm Page 10 Monday April 1 2002 12 43 PM ...