BIRD 428B-83H-01-C-110, Инструкция по установке и эксплуатации

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TX RX Systems Inc. Manual 7-9487-3 05/05/11 Page 2
circuitry continuously monitors the DC power oper-
ation of the primary quad-amplifier and automati-
cally switches to the identical secondary quad-
amplifier if conditions indicate a primary malfunc-
tion. Fault detection circuitry also provides at-a-
glance status reporting, with front-panel LED’s and
an LCD display. The system specifications are
listed in
Table 1 .
Tower Top Box
The quad-amplifier in the tower top box amplifies
the weak received signal before the signal enters a
long and lossy transmission line, thus preventing
the line loss from degrading the signal-to-noise
ratio. The quadrature amplifiers have a separate
power circuit for each half of the amplifier which
provides component redundancy as well as unsur-
passed IM performance. Microprocessor controlled
fault detection circuitry in the tower top box pro-
vides continuous monitoring and switching of each
quad amplifier while sending operational data to
the base unit front panel for at-a-glance status
reporting and form-C contact switching for alarm
integration. Included in the tower top box is a pre-
selector filter, amplifier “A” and amplifier “B,”
switching circuitry, control board and lightning
Electrical Specifications
Frequency Range 792 to 824 MHz
Net Gain 23 dB (typ)
Noise Figure 2.7 dB (typ)
Backup Amplifier Switching Solid State RF Switch
Integrated Test Port Isolation 33.5 dB (typ)
Preselector Type
Loss
Rejection
7-pole TEM Bandpass
with cross-coupling
<0.8 dB (typ)
>60 dB @ 776 and 851 MHz
LNA Type
Gain
Noise Figure
3rd Order Input IP
2-stage Quadrature
integrated into filter
26 dB (typ)
1.2 dB (typ)
18 dBm (typ)
Impedance 50 Ohms
Antenna Port VSWR 2 : 1
Power Requirements 12 VDC @ 1.25 A
Lightning Protection Impulse Suppressor on all external connectors
Operating Temp Range -30° C to +60° C *
Mechanical Specifications
Enclosure Modified NEMA 4x:
weather resistant
Connectors N -female
Dimensions (HWD)
not including mounting tabs and connectors 18” x 6” x 6”
(457 x 152 x 152 mm)
Net Weight 17.5 lbs
* The tower top amplifier will function up to 70°C without shutting down. However, the specifications are not
guaranteed.
Table 2: Tower box specifications. Values are typical unless noted otherwise.