Operating instructions

GENERAL INFORMATION
1-6
Operating instructions for each of the SYSTEM test options is given in separate supplements to
this manual. These supplements are supplied, as appropriate, with Service Monitors fitted with
SYSTEM testing options.
Avionics systems
The Avionics SYSTEM test facility is capable of carrying out functional testing and performance
evaluation of airborne radio navigation and communication equipment. Appendix B, Avionics
System, covers the operation of this facility.
Spectrum analyzer
The SPEC ANA mode allows ‘off air’ and directly coupled RF signals to be studied and
monitored.
Sideband spread, harmonic levels and RF interference can be examined.
The frequency range of the spectrum analyzer is from 100 kHz to 1.0 GHz with the start and stop
frequencies of the sweep infinitely variable from within this range.
The tracking generator permits frequency response tests to be made to frequency dependent
circuits and the frequency offset facility extends this capability into the area of frequency shifting
circuits, such as mixers.
The ‘Look and Listen’ function gives the ability to demodulate a signal displayed on the spectrum
analyzer and monitor the signal obtained on the built-in loudspeaker, on headphones or other data
output equipment.
AF testing
Service Monitor
Amplifier
Under
Test
AUDIO
AUDIO
C3244
Fig. 1-6 AF test setup
The AF testing mode allows the dual AF generators and the tones generator to be used as a signal
source. The AF voltmeter, distortion meter, bar chart displays and the AF counter can all be used
to provide data relating to signals applied to the AF input connector. The digital oscilloscope is
also available for studying AF waveforms.