Amplifier Setup |
Amplifier Level Control
Signal levels vary in a cable system primarily because cable attenuation changes with temperature. Other components such as passives and amplifier hybrids are also affected by temperature changes. To automatically compensate for these signal level fluctuations and control output level, you must select the optional ADU/QADU. For improved output level stability, use of the ADU/QADU is recommended.
When necessary and appropriate, you can also use manual gain control. The BLE100 gain is then determined by the potentiometer marked MAN on the electronics chassis cover.
Manual Gain Control
To use manual gain control:
1Verify that the electronics chassis is installed correctly.
2Ensure that there is continuity in the forward path by installing the
3Ensure that the drive control select jumper is in the MAN position.
4Use a
This carrier should be at standard analog level,
5Verify that the input level agrees with the design specification input.
If the level is different from design, adjust accordingly. For example: the design level is 19 dBmV at the highest frequency and the design pad value is
If the actual levels are significantly different from the design levels, it is recommended that you investigate or consult system management before proceeding.
6Connect the
7Turn the manual gain reserve (MAN) control (illustrated in Figure
Table
Gain reserve versus ambient temperature
Temperature |
|
| Gain Reserve |
° | ° |
| 3 dB |
Above 110 F (43 C) |
| 4 dB | |
° ° | ° | ° | |
32 F (0 C) to 110 F (43 C) |
| ||
° | ° |
| 5 dB |
Below 32 F (0 C) |
|
|
BLE100 Installation and Operation Manual