Messenger

The Marconi Messenger is a Secondary Surveillance Radar (SSR) system developed in the United Kingdom. It operates at 1030 / 1090 MHz and features the S-1095 antenna, a large vertical aperture, open planar array with a gain of 29 dB, which can be used independently or co-mounted with a primary radar antenna. The S-2101 interrogator-transponder is a single rack-mounted unit incorporating an off-boresight azimuth measurement system, with solid-state output stages composed of up to four 500 W modules, providing a peak power of up to 2 kW. The S-7204 decoder-extractor utilizes a hybrid hardware/firmware design with bit-slice processing for robust performance and flexibility, handling complex corrupted replies without overload. The Messenger system is designed for easy upgrade to full Mode-S capabilities and complies with ICAO and STANAG 5017 requirements.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/14.ssr/karte003.en.html