Cisco Cisco 1 GHz GainMaker Amplifier Guía De Instalación
Balancing the Forward Path
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3 Measure the output tilt again, and then return to step 1.
To Set the Output Level
After setting the tilt, complete the following steps to select the proper pad values for
the amplifier. The output level of the amplifier is set by selecting the proper pad
value.
1 Connect the test probe to the forward main output test point.
2 Measure the output level at the highest design frequency, and compare this level
the amplifier. The output level of the amplifier is set by selecting the proper pad
value.
1 Connect the test probe to the forward main output test point.
2 Measure the output level at the highest design frequency, and compare this level
with the design level (on the design print).
3 Is the measured output level within ±0.5 dB of the design level?
If the output level is within ±0.5 dB of the design output level, proceed to step
5.
5.
If the output level is more than the design output level, replace the forward
input pad with a higher value pad.
input pad with a higher value pad.
If the output level is less than the design level, replace the forward input pad
with a lower value pad.
with a lower value pad.
4 Repeat steps 2 and 3 until the output level is correct.
Note: On the High Gain Dual, the type of plug-in signal director installed directly
affects the signal level measured at the Aux RF output test points. This is because
the Aux RF output test points are located after the signal director in the forward RF
signal path. The test points now reflect the actual output of the port.
It is important to determine if the Aux output level specified on the design print is
the level before or after the signal director.
affects the signal level measured at the Aux RF output test points. This is because
the Aux RF output test points are located after the signal director in the forward RF
signal path. The test points now reflect the actual output of the port.
It is important to determine if the Aux output level specified on the design print is
the level before or after the signal director.
If it is the level after the signal director (port output level), the test point
should match the print design level.
should match the print design level.
If it is the level before the signal director, the test point level should be “x” dB
lower than the print design level, where “x” is the insertion loss of the signal
director feeding the particular Aux port being balanced.
lower than the print design level, where “x” is the insertion loss of the signal
director feeding the particular Aux port being balanced.
5 Proceed to the next section, To Set Up Automatic Gain Control.
To Set Up Automatic Gain Control
This section provides procedures and tables for configuring and aligning the AGC in
the 1.2 GHz GainMaker System Amplifier. AGC attenuator values are required to
select the proper AGC attenuator value based upon actual AGC pilot carrier output
level. See To Select the AGC Pad Value.
the 1.2 GHz GainMaker System Amplifier. AGC attenuator values are required to
select the proper AGC attenuator value based upon actual AGC pilot carrier output
level. See To Select the AGC Pad Value.
Note:
Output levels are measured at the pilot frequency.
The standard single-pilot AGC makes amplifier output adjustments based on the
level of the pilot frequency carrier. Activate the pilot carrier with its final
unscrambled video source before beginning balance and alignment.
level of the pilot frequency carrier. Activate the pilot carrier with its final
unscrambled video source before beginning balance and alignment.