Motorola BLE100 - Manual (Page 28)

Amplifier Setup 3-7
BLE100 Installation and Operation Manual
The information in Table 3-2 is shown as a graph in Figure 3-2:
Figure 3-2
Frequency versus cable slope
0
1
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
40 45 50 72
108 150 21
1
250 300 350 400 450 550 750 870
1003
Cable
slope
(dB)
Frequency (MHz)
SCS-10
SCS-9
SCS-8
SCS-7
SCS-6
SCS-5
SCS-4
SCS-3
SCS-2
SCS-1
Input and Midstage Pads
Install Model JXP-*B pads to attenuate the signal per system design drawings. Generally, this
consists of attenuating excessive input levels. You should pad the input to system levels for
unity gain. Select and install the specified pad in the socket labeled
JXP - IN on the chassis cover.
You can use the midstage pad ( JXP - MID ) to adjust the gain level and achieve the gain
specification. Refer to Section 6, “Operating Tips,” for midstage padding information and
recommendations.
Flatness Control
The LDR/9/1G circuit board includes flatness controls and a fixed cable equalizer for 1003 MHz.
This equalizer, plus the contribution of the hybrid gain stages, produces approximately the dB
of slope indicated by the model number (9 dB of tilt with an LDR/9/1G).
You can adjust the LDR variable resistors and capacitors to flatten the response across the
operating band. Use C1, C2, R1, and R2 on the LDR board shown in Figure 3-3 for low-end
flatness response. The low-end flatness controls compensate for the roll-off caused by the diplex
filters. Adjust C3 and R3 for a flat response across the mid-band. Adjust C7, C8, and R8 for a
flat response across the band. Adjust C6 for maximum gain at the high end.
ƒ C1 produces a peak that is centered just below the lowest forward frequency and varied in
amplitude by R1.