Receiver and Controller

This is the controller. The motor control and data cables run from here to the receiver and dish control motors. The RS-232 port connects to a local computer.


The receiver uses digital technology with a 8-bit analog to digital down converter (AD9283) digital downconverter GC1011A and Motorola 56F803 digital signal processor (DSP). The receiver and the low noise amplifier are mounted at the feed of the antenna. The receiver is controlled remotely using a STAMP microprocessor and RS-232 communications. Also shown is the diode calibrator.


Radiometer Characteristics


L.O. Frequency range 1370-1800 MHz
L.O. Tuning steps 40 kHz
L.O. Settle time <5 ms
Rejection of LSB image >20 dB
Bandwidth/Resolution Modes 1200/8 kHz*
(Currently supported in ver 1.0 firmware) 500/8 kHz
- 250/4 kHz
- 125/2 kHz
I.F. Center 800 kHz
6 dB I.F. range 0.5-3 MHz
Preamp frequency range 1400-1440 MHz
Typical system temperature 150K
Typical L.O. leakage out of preamp -105dBm
Preamp input for dB compression
from out of band signals
-24 dBm
Preamp input for intermodulation interference -30 dBm
Control RS-232 2400 baud
* The 1200 kHz wideband is synthesized using 3 500 kHz bands stitched together from a frequency scan.


Digital Receiver
Digital Receiver Board




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