1. PRESENTATION ............................................................................................................................... 9
2. DESCRIPTION .................................................................................................................................. 9
2.1
Front panel ............................................................................................................................... 9
2.2
Rear panel .............................................................................................................................. 10
3. USE ................................................................................................................................................. 10
3.1
3.2
Different uses ......................................................................................................................... 11
4. CHARACTERISTICS ...................................................................................................................... 12
5. MAINTENANCE .............................................................................................................................. 13
5.1
Fuse replacement .................................................................................................................. 13
5.2
Cleaning ................................................................................................................................. 13
5.3
Metrological inspection .......................................................................................................... 13
6. APPENDIX ...................................................................................................................................... 33
The ORITEL IR 205 SWR indicator is a selective voltmeter with an integrated amplifier whose frequency
can be adjusted around 1,000 Hz.
This indicator can be used for four main functions:
Measurement of the standing wave ratio (SWR) using a measuring line
Measurement of insertion loss or attenuation
Zero indicator for a measuring bridge
Indication of the field received by an antenna
The instrument is designed to be associated with a square-law demodulator, and the microwave signal
present at the demodulator input must be amplitude-modulated to 1 kHz.
The instrument is essentially made up of a selective high overvoltage circuit associated with a LF
amplifier, a detector stage followed by a galvanometer and a stabilised power supply.
The input attenuator can be adjusted in jumps, while the gain can be adjusted continuously for the
intermediate positions.
The level is read on a galvanometer directly calibrated in dB according to a square law. A special circuit
enables the scale to be expanded in dB for precise measurements.
2.1
Front panel
(see 6. Appendix)
Mains push button (on / off)
Power LED (lights up red when the instrument is brought into operation)
CONTENTS
1. PRESENTATION
2. DESCRIPTION
9