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Type | HEMT cooled | |||
Channels | 2 | |||
Receiver Noise | 15K | |||
Frequency range | 7.95 - 9.15 GHz | |||
Polarization | LHC/RHC | single horn | ||
Calibration | Noise diode | phase cal for VLBI | ||
1st IF | 2.2 -3.2 GHz | Synthesizer 1 = | ||
LO1 | Valon 5009 | fsynt.1 = 4.4 - 6 GHz | (preset 5.55 GHz) | |
2nd IF | 0 - 1 GHz | |||
LO2 | Valon 5009 | fsynt.2 = 2.2 GHz |
Simplified Block Diagram of the complete receiver, (RK on 19.3.2019)
The 8.6 GHz system is a secondary focus receiver with cooled HEMT amplifiers and a cooled polarization transducer. The system is set up for receiving both circular polarizations. Since the calibration signal is injected through the directional coupler directly following the horn, it is linearly polarized. The feed is fed through the inner part of the 2.3 GHz offset paraboloid feed system of the S130mm receiver to form a S/X-band system for VLBI observations.
The receiver is extended to 1.1 GHz instantaneous bandwidth in the VLBI IF. To use the full bandwidth the LOs have to set to the following values:
Synth.1 = 5.646 MHz
Synth.2 = 2.204 MHz
Only with these fixed settings the full bandwidth can be accessed (see also block diagram).