User Manual

Mission Valley Radio Repeater Equipment + Upgrade
User/Maintenance Handbook
Handbook No. 50-078021HBKM Page 36 of 85
3.12.1 Description
The duplex shelves are part of the VHF amplification system and like the simplex shelves, have
crystal filters instead of bandpass filters to set frequencies and bandwidths. There are two downlink
channels and two uplink channels, the downlink paths having isolators fitted to each of the 5Watt
output stages to prevent interfering reflections from the other channel.
The uplink channel modules have a dedicated noise muting circuit fitted externally to the channel
module which operates when the downlink path is active.
All amplifiers have built-in alarms which are configured as a summary, volt-free relay contact pair
terminating at pins 1 & 2 on the rear panel mounted ‘D’ type alarm connector.
3.12.2 Technical Specification
PARAMETER SPECIFICATION
160.665MHz (50-078011/1, D/L)
160.935MHz (50-078011/1, U/L)
160.380MHz (50-078011/2, D/L)
160.905MHz (50-078011/2, U/L)
160.710MHz (50-078011/3, D/L)
161.415MHz (50-078011/3 U/L)
161.565MHz (50-078011/4, D/L)
Duplex channel frequencies:
160.755MHz (50-078011/4 U/L)
Gain: >90dB
Gain Adjustment: 0 – 15dB (in 1dB steps, both paths)
Uplink Power: >5.0Watts
Downlink Power: >5.0Watts
Uplink: +48dBm
IP3
Downlink: +48dBm
Noise Figure: <6dB
AGC level: -2dBm (uplink & downlink)
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