EMS
Wireless
EMS
Wireless
EkoMini Manual
34
5.3.2 EkoMini 800 MHz A Band Series:
Switches 3 and 4 are used to minimize the gain of the control channels in the adjacent
Cellular B band by moving the position of the upper “skirt” of the repeater’s bandpass
filter. Figure 11 illustrates this. The switches are set to position the 3-dB roll-off point
of the filter on specific AMPS channels as shown in Table 9 below. The units are
factory set with the filter centered at the center of the band, so channels at the extreme
lower and upper band edges are filtered o ut equally. If the switch settings are
changed, be sure to press the “reset” button to make these changes effective.
Table 9: Cellular A Band Bandpass Filter Switch Positions
Band
Selection for
“A” Band
3-dB Roll-off Begins on
AMPS Channel
Switch
3
Position
Switch 4 Position
A
1
Channel 329 – 879.870 MHz
On
On
A
2
Channel 325 – 879.750 MHz
On
Off
A
3
Channel 321 – 879.630 MHz
Off
On
A
4
Channel 317 – 879.510 MHz
Off
Off
0
-10
-20
-30
-40
Filter Response
879.0
879.1
879.2
879.3 879.4
879.5
879.6
879.7
879.8
879.9 880.0
880.1
Ch. 317
(879.510
MHz)
Ch. 321
(879.630
MHz)
Ch. 325
(879.750
MHz)
Ch. 329
(879.870
MHz)
-3 dB
Cellular
A Band (upper portion)
Switch
Position "A4"
Switch
Position "A3"
Switch
Position "A2"
Switch
Position "A1"
Frequency, MHz
Cellular
B Band (lower portion)
Figure 11: Cellular A Band Filter Switch Characteristics
