User Manual

Table Of Contents
Mission Valley Radio Repeater Equipment + Upgrade
User/Maintenance Handbook
Handbook No. 50-078021HBKM Page 19 of 85
3.7.1 Description
This shelf is the interface between the system’s 800MHz bi-directional tunnel amplifiers and the off-air
antenna.
In the downlink direction, the incoming antenna RF is directed through a bandpass filter to a pair of
20dB gain low noise amplifiers that have a switchable 0-30dB attenuator between them. The resultant
single path is then divided several times and fed out of the shelf to the channel selective modules (x
24). When the outputs from the channel modules return, they are combined and exit to the two power
amplifier shelves that serve the East and West tunnel leaky feeders.
The uplink path originates from the tunnel antennas, and is band-selectively amplified and fed to a
pair of 10W power amplifiers. This final amplification stage in the uplink path has an automatic gain
control detector and attenuator to help negate the overloading effect of someone operating a mobile
close to the LCX tunnel antennas.
Note that this shelf has its own, dedicated mains driven, 12-15V DC PSU unit.
3.7.2 Technical Specification
PARAMETER SPECIFICATION
851-869MHz (Downlink)
Frequency range:
806-824MHz (Uplink)
Downlink output power: N/A
Uplink output power: 10Watts (x2)
AGC: Fitted in uplink path
AGC dynamic range: >35dB
Height: 8U
Width: 19" (482.6mm)
Shelf
dimensions
Depth: <450mm (excluding connectors & handles)
operational: -20°C to +60°C Temperature
range
storage: -40°C to +70°C
Weight: <15kg
Shelf gain: 60dB (typical)
Impedance: 50
Humidity: 5 – 95% non-condensing
RF Connectors: N type female
Environmental protection: IP44
Case: Alocrom 1200/Iridite NCP coating
Heatsinks: Black anodised aluminium
Handles: Silver anodised aluminium alloy
Finish
Fascia: Painted to RAL7035