Another Itty Bitty Radiotelescope

This project consists of the custom building of an itty-bitty-type radio-telescope for the observation of objects in space. We won’t do a deep explanation of everything that it could take to be made, because its design relies on other radio-telescopes that we’ve found in the web. This was the first approximation of what we intended to do, then, for aesthetic reasons, we changed it into a more compact diagram.

First, we planned to do it with a satellite dish to receive a signal, an LNB to catch the noise, a Sat-Finder to catch the space-coming signal for then being processed through a computer. The diagram includes a system that controls the antenna through Arduino and some engines.

Next, we thought that the search for the Sat-Finder would be much easier than it actually was, but we found a pretty good one:

In the picture above we plugged some batteries to test its performance, the LNB is also pictured (working, too).

Finally, here we have the components needed:

• Arduino UNO (or some other Arduino).
• Satellite antenna.
• A Satellite Finder (a basic SatFinder could be enough).
• A lot of coaxial cable.
• 3 F connectors.
• 2 stepper motors (we use a pair of reused stepper motors).
• A 24 v power supply.
• Another no documented yet material...

The S.F. works not only as a support for the pointing of a TV dish, but also for a telescope like this planned one. It has a buzzer with different pitch according to the signal strength, which allows us to remove the original cables and plug them into the computer’s 3.5 mm jack port, and then analyze the signal with an audio processing software, like Audacity, in order to recognize several objects with different frequencies. Another important thing discussed was putting into action our knowledge in Python for the processing of the data.
Pictured above, was the first approximation of the program that runs a frequency-processing code.

After some discussion regarding the best way to take the sign (and the cheaper), we decided to choose for the Arduino, for now. We moved from having a S.F. filled with voided noise towards a card with so many welded cables in order to control the potentiometer and the other knobs useful for the design.

(If you look closely, we almost nailed it!)

To support us in the making of this project we headed to Google constantly, searching for a great quantity of papers and outreach articles related with this. To provide power, we actually required an energy supply of at least 24 V, luckly we found an ATX source which facilitates the job and serves as a bank of tests. In the picture below we’ve already pluged the Arduino, starting up the data sampling.

After welding some cables, we tested the Arduino. We noticed that, while varying the sensitivity with the potentiometer, the results could be matched into a graph. The next graph shows the level when the potentiometer is at its peak point, which indicates the higher given sensitivity.

The next step is finding a way to modeling the antenna and, by doing this, obtain the best control of positioning. The method consisted in drawing a design on a CAD software, detailed as possible, so we could have theoretical data corresponding to its geometry like the moment of inertia or center of mass. We also found on the web an approximation of our antenna modeled by others ready to put our data and calculate this parameters.

This is what we have to the moment. It's necessary more time to end the project. The project Isn't completed, the next step will be automate the antenna with the Arduino and the stepper motors.

All new advances in the project, you can check it in the following link: silencioaquemarropa.blogspot.mx. Feel free to read the another texts published in the blog.