User Manual

Fibre Optic Master and Remote Site
User Handbook
Document Number: 60-212701HBK - Issue No. 1 Page 28 of 50
4.2.4.5. Low Noise Amplifier (11-007402)
The 30dB gain low noise amplifier used is a double stage solid-state low-noise amplifier. Class A
circuitry is used in the unit to ensure excellent linearity over a very wide dynamic range. The two
active devices are very moderately rated to provide a long trouble-free working life. There are no
adjustments on this amplifier, and in the unlikely event of failure then the entire amplifier should be
replaced. The amplifier features a dedicated, in-built alarm monitoring system which gives a TTL
‘open collector’ type switched signal on alarm, this is then integrated using a built-in relay to give a
volt-free contact for summation into the main alarm system.
11-007402 Specification
PARAMETER SPECIFICATION
Frequency range 380-500MHz
Bandwidth <140MHz
Gain 30-32dB
1dB Compression point +22dBm (typical)
3rd order intercept +34-35dBm (typical)
Input/Output return loss >20dB
Noise figure <1.3dB
Connectors SMA female
Supply 300-330mA @ 24V DC
operational -20°C to +60°C Temperature
range
storage -40°C to +70°C
LNA ‘D’ Connector Pin-out details
Connector pin Signal
1 +ve input (10-24V)
2 GND
3 Alarm relay O/P bad
4 Alarm relay common
5 Alarm relay good
6 No connection
7 TTL voltage set
8 TTL alarm/0V (good)
9 O/C good/0V bad
9-Way Pin-Out Graphical Representation