3-10
Amplifier Setup
SLE*-* Installation and Operation Manual
PRELIMINARY - Motorola Internal Use Only
7
Check the amplifier output tilt by measuring the high-band- and low-band edge carriers.
!
High = channel 136 (865.25 MHz)
!
Low = channel 2 (55.25 MHz) or channel 3 (61.25 MHz)
!
If the tilt is less than required, install a higher value input equalizer.
!
If the tilt is greater than required, install a lower value input equalizer.
!
If the high value equalizer provides too much tilt and the low value equalizer provides
too little tilt, use the lower value equalizer. Under-equalization is preferred to
over-equalization.
If you use an SCS cable simulator and the design value is changed, you must also adjust the
input pad. Each 1 dB increase in SCS value equates to 1.1 dB of loss at 870 MHz. Therefore,
to maintain a proper gain level, it is necessary to adjust the input pad value as follows:
!
For each increase in SCS value, decrease the input pad by 1 dB.
!
For each decrease in SCS value, increase the input pad by 1 dB.
!
If you replace an SFE with an SCS, reduce the value of the input pad by the value of the
SCS.
8
Measure the output level at the highest frequency.
It should be within 1 dB of the system design level. If it is not, you must adjust the
mid-stage pad (
JXP
MID
) accordingly. Refer to Section 6, “Operating Tips,” for mid-stage
padding information and recommendations.
SLE-TDU
The SLE-Thermal Drive Unit (SLE-TDU) senses temperature and controls the SLE-Bode board.
It is assumed that the cable is subjected to the same or similar temperature; therefore, you
should not use the SLE-TDU for underground installations.
To set up the SLE-TDU:
1
Place the jumper on the SLE-TDU (Figure 3-5) to the
LOW
,
MEDIUM
, or
HIGH
position to
specify the amount of cable for which the SLE-TDU compensates at the highest frequency
preceding the SLE*-* station. Low = 0 dB to 15 dB of cable, medium = 15 dB to 30 dB, and
high = 30 dB or more of cable.
Figure 3-5 illustrates the jumper and thermal level control on the SLE-TDU:
Figure 3-5
SLE-TDU cable selector
Low
Medium
Thermal
level
High
