User Manual

Table Of Contents
Mission Valley Radio Repeater Equipment + Upgrade
User/Maintenance Handbook
Handbook No. 50-078021HBKM Page 32 of 85
3.10.1 Description
The VHF simplex shelves are two-path, single frequency cell enhancers that cut the DC power (and
thereby mute the amplifiers) to the opposing path whenever a signal is detected. This is achieved by
using highly accurate crystal filters to set the exact channel frequency and speciality channel selective
modules that react to detectors placed in each path. There are also switched attenuators before and
after the channel modules in order to accurately set the RF threshold levels for correct simplex
operation (this will already have been achieved at the time of final system test and should not need
adjustment). Isolators at the outputs of each path protect the power stages from potentially damaging
stray interference from other channels.
Each amplifier in the simplex CE shelves has an alarm as do the channel modules and the summary
alarms terminate at the rear panel mounted 9-way ‘D’ connector, pins 1 & 2.
3.10.2 Technical Specification
PARAMETER SPECIFICATION
161.295MHz (50-078010/1)
Simplex frequencies:
159.0-161.0MHz (50-078010/2)
Gain: >90dB
Gain Adjustment: 0 – 15dB (in 1dB step)
Uplink Power: >5.0Watts (typical)
Downlink Power: >5.0Watts (typical)
Uplink: +48dBm
IP3
Downlink: +48dBm
Noise Figure: <6dB
23dB (downlink)
Channel module gain:
24dB (uplink)
VSWR: better than 1.5:1
RF Connectors: N type, female
operational:
-20°C to +60°C
Temperature
range
storage:
-40°C to +70°C
Case: Alocrom 1200/Iridite NCP coating
Heatsinks: Black anodised aluminium
Handles: Aluminium alloy
Finish
Fascia: Painted to RAL7035
1 U/L amplifiers
2 D/L amplifiers
Alarms Fitted
(volt-free contacts/TTL)
3 Channel modules