 |
- On this page I will try and explain what I did when I set up LoBERT. That way you can follow along and hopefully have your own system built in no time.
- The whole process of building a Radio Telescope is not that hard. You just have to have to be pateint and not rush things. I started out by trying to build my own dish out of old alluminum arrows that I had laying around the house. Needless to say that went over link a piece of lead trying to swim! After about two weeks of tinkering with that I started to look around Hinesville, Ga at the satellite dealers to try and buy a new dish. Well they all wanted WAY to much for them. I finally found a guy living about ½ mile from my house that didn't want his 15 foot (4.5 meter) dish. Believe it or not he told me to just get the thing out of his yard. So who says that you have to buy a dish??? Well I tore the thing down and loaded it in my minivan. Once I got home the wife thought I had done lost my mind. I put the pole for the dish in the ground on a 25 degree angle to the west. I had to do this in order for the dish to be able to track due South to North line. That way I could use it as a drift scan. While I was waiting for the concrete to dry around the pole I started building the ADC, Analog-to-Digital Convertor. This little device takes and converts the power that you put into it into a digital format. That way you can record the data on your computer. I used the TLC548 8-bit ADC from Texas Instruments for the simple reason that no one in town had anything else. They even looked at me strange when I asked for this one. Guess not to many people in Southeastern Georgia build Radio Telescopes. BTW, when you start building your system, don't tell the people at Radio Shack what you are doing. Cause everytime that I would ask them for a piece they would ask me if I was doing something illegal. I understand why they did it, but you would think after about 12 trips to the same store within a weeks time they would know what you are up to. Well, after the concrete dried and I mounted the dish to it. I connected a Satellite Signal Meter, a device that measures the amount to radio waves that the amplifier is receiving, to a short piece of coax which was connected to a DSS LNBF, Low Noise Block downconverter Feed, that's the piece that sits out on the arm of a DSS/DirectTV dish. I had opened the Signal Meter up to be able to get to the two power lines that controlled the buzzer in it. I connected two wires to this and ran them into the house where I had the ADC connected to my old 386SX25 computer running software that I had written for it. The other side of the Signal meter has a place for a coax cable to connect to it for power. I ran a coax into the house and hooked it up to a Radio Shack 12-volt regulated power supply. When you do this make sure that you put the center conductor on the positive side of the power supply, that way you don't sit there and watch everything that you have worked for go up in a quick puff of smoke. I took a AA battery and connected it to the ADC and fired up the software, just to make sure that it worked. After that I reconnected the two lines coming in from the meter to the ADC and crossed my fingers as I flipped the switch on the power supply. As soon as I filpped it the ADC came alive with all kinds of readings. I couldn't wait for the sun to transit so I did the quick way of testing it. I got my wife to sit inside with a walkie talkie and I ran out to the dish. I unbolted the elevation arm and the bolts holding the dish to the pole and swung it aroung to face the sun. It took a few tries to get the sun in the right spot on the dish, but I almost dropped the dish when my wife called me on the radio and told me that the ADC was reading 5 volts, that's the max of the ADC chip that I had used. I spun the small plastic box that the meter is housed in around so that I could watch it and slowly moved the dish and sure enough LoBERT had seen it's first light. I have since been trying to figure out a way that I can tell at what angle the dish is pointing at from inside the house, That way I don't have to move it and then go outside to check the angle. The picture, scan, below was taken on 30 May 2000. It's a drift scan of the sun. I will include more scans as I work out the bugs in the system.
|
