Model A5-24 Operation And Service Manual
A5-24 Manual 20 March 2002
Page 5 of 10
Distribution Amplifier A5-24
Operating Procedure
Introduction
The Quartzlock model A5-24 is a linear distribution amplifier designed for standard frequency
distribution between 1 MHz and 100 MHz. The circuit is based on a number of balanced linear
amplifiers with high reverse isolation and low phase noise. Twelve of these amplifiers are used to
drive the twelve 50
Ω
outputs. They are called the output amplifiers in the following description. A
modified version of the output amplifier with a gain control, called the input amplifier, drives a
twelve way passive power splitter. This divides the signal with an insertion loss of about 12 dB, and
provides isolation of about 20 dB. The output amplifiers each have an output signal monitor circuit,
which is used as part of the output fail monitoring.
Input
One input is provided. This has input impedance of 50
Ω
. The input level should be between 0 and
+13 dBm.
Outputs
Twenty-four outputs are provided. These have source impedance of 50
Ω
, and will provide 13 dBm
nominal into a 50
Ω
load. Maximum output is up to 16 dBm.
Power Supply
This unit operates from its own mains driven power supply, set at the factory to operate from 240V
ac. An internal switch on the power supply enables operation from 120V ac if required. The mains
fuse may need increasing in rating at 120V mains supply.
