This 12GHz system was built as an educational program to detect microwave
thermal radiation from the Sun, the cold sky, the ground, the human body,and
so on.
Examples on what can be done with a similar system is described by
William Lonc in Classroom
Radio Telescope.
It is very easy to implement such a system: The receiving equipment
is a 83 cm offset dish with LNB connected via a short coax cable to a satellite
finder that replaces the receiver.
The LNB has a Noise Figure of 0.7dB, it receives from 12.50 GHz to
12.75 GHz, the output is from 950 MHz to 1750 MHz and feeds the satellite
finder (Satfinder).
The Satfinder is normally used to set the dish towards a satellite
when installing an equipment for the reception of satellite television.
It is a very small box with an analogic meter that shows the intensity
of the signal, the gain is varied via a potentiometer.
The built-in analog meter has ten graduation marks, when the dish is
pointed to the Sun the meter shows a sharp peak.
The satellite finder was modified as follows: A shielded two-leads
cable was soldered to the meter terminals and the other end of the cable
is connected a A-to-D converter.
The output of the satfinder goes normally, via a coax, to the receiver
and the receiver powers the satfinder and the LNB with 13/18 Volt through
the coax.
In our case a 15 volt regulated power supply is connected directly
to the output.
The data from the A-to-D converter are then processed by the Radio-Sky
Pipe software.
This is the Satfinder , protected by a polystirene container, on the left is the coax cable to the LNB, on the right is the output F-plug connected to the power supply,and barely visible, the cable to the A-to-D converter.
