Tabla de contenido
Idiomas disponibles
Idiomas disponibles
4. Turn the ATI interstage variable attenuator fully clockwise (min attenuation).
5. Read the level of the highest frequency carrier.
6. Turn the ATI attenuator to reduce this highest frequency level as follows
2 dB if the ambient temperature around the preceding cable span is +25° C.
1 dB ditto if it is +55° C.
4 dB ditto if it is -20° C.
(
)
*
The numbers in dB are a rough estimate. The correct value comes from the engineering calculations, and it is
determined by the changes in attenuation of the preceding cable over temperature.
7. If the engineering calculations are correct, the level of the highest frequency carrier after the
reduction performed in the previous point must be above the design level. If the difference is not
more than 3 dB, turn the ATI interstage variable attenuator counterclockwise to set the design
value. If the difference is 3 dB or more, change the PAF and/or the PAA positions (the change in
the last only is possible if additional amplification is not implemented) so that the difference is less
than 3 dB (always above the desired level); then set the design value by turning ATI counter-
clockwise.
8. Adjust the ECE variable equalizer to achieve the desired wideband response —flat or with the
planned pre-emphasis.
Important: In order to reserve a margin for automatic control, the ECE variable equalizer must allow
the following slope variations from its setting position:
If the setting or the ambient conditions are not possible, change the PSC link position to "3 dB", or if
necessary to "6 dB", so that the wideband response is achieved with a final setting value of ECE
which admits the aforesaid turns.
9. Disconnect the power (by changing the position of the remote powering input plug-in if the amplifier
is line powered, or disconnecting from the mains if the amplifier is mains powered).
10. Change the first and fourth plug-in links of the ALSC/RW/INGRESS group from the initial positions
indicated as 0 and 9 to the ones indicated as 1 and 8 (see Fig. 8).
11. Insert the ALSC circuit card into place by aligning the guide of the case with the O hole in the main
board (see Fig. 9); make sure the clips match with the pins on the board.
12. Turn both the ATI interstage variable attenuator and the ECE variable equalizer fully clockwise.
13. Connect the power again.
14. Set the design output level and the slope by adjusting both the ATI interstage variable attenuator
and the ECE variable equalizer. The adjustments affect each other slightly, so the sequence must
be repeated two or three times.
15. The pilot lamp L2 (see Fig. 10) must light green. At extreme temperatures for the cable, it can light
amber or red (very high or very low temperatures, respectively); if this occurs at normal temperature
(15-25° C), the setup process must be carried out again from the beginning.
16. Disconnect the spectrum analyzer from the test D port and replace the F load.
INPUT TEST PORT
The amplifier has an internal RW output test port which can become transformed in FW input test port; to do it, place
the PE1 and PE2 plug-in links in the positions indicated
30 ±1 dB lower than the real value.
After measuring return the PE1 and PE2 plug-in links to the established input configuration positions.
20
±2 dB (turns to left and right), if the ambient temperature around the preceding ca-
ble span is +25° C.
- 4 dB (turn to right), ditto if it is +55° C.
+4 dB (turn to left), ditto if it is -20° C.
T
on the internal label E1. The measured levels are
(
)
*
:
Tabla de contenido
