Parabola Calculator version 2.0
About This Program
This Freeware program was written to help you design solar collector or wifi projects using parabolic reflectors.
Whether you're improving the signal strength of your wifi antenna, or designing a satellite antenna or solar trough,
this program calculates the focal length and (x, y) coordinates for a parabola of any diameter and depth. It can
help you determine what size and shape to make your parabola very quickly. Version 2 includes Wifi calculations
for centered or offset feedhorn dishes. If you would like modifications to the program to make it more useful to
you or to send feedback, you can email me here
Thanks to Frank Schindler
for the curve fitting code used by this program, you can visit his page here
Thanks to Bernhard S. Müller for helping develop and beta testing version 1, you can visit his site here.
Thanks to Edisher Giorgadze for helping develop and beta testing version 2, you can visit his page here.
Thanks to Wayne J. Hill for giving me the source code for the DXF file format, you can visit his site here.
Thanks to Paul Wade for supplying the WiFi text, calculations and code, they were copied directly from his hdl_ant program, you can visit his site and download his program here.
Download the Program
This program was written in Visual Basic 6, and should run on Window 95 or later. The program will run under Linux
using Wine if you copy the dependancy files into the folder where the program resides. The program requires Visual
Basic 6 runtime files, your computer may already have them installed. I would try downloading the smaller file (program
only) first and seeing if it runs. If not, delete it and download the Windows Installer to perform a standard Windows
Bernhard S. Müller's SolarTechnik.com
La Cuisson Solaire
Welcome to ReCombinant Design!
The Solar Cooking Archive Wiki
The Wikia Parabolic Solar Reflectors Page
Wayne J. Hill's CodeMangler.com
Paul Wade's N1BWT 10 GHz Page
The Third Paradigm (OT)
1.When you run the program you will see the main program window shown here.
Use any units you like, as long as you use the same units for both the Depth and Diameter. You can also
select Diameter and f/D as inputs using the Options > Select Inputs menu choice. I recommend using
smaller units: inches instead of feet, or millimeters instead of meters, to increase the resolution of your
2. After you enter some numbers into the Diameter and
Depth text boxes and click the Calculate button, the program
will show you the scaled down shape of the parabola you described, and it will calculate
the (x, y) coordinates of the curve of the parabola in 16 straight line segments. You can
calculate the (x, y) coordinates using anywhere from 2 to 1000 segments.
3. To see what the shape and focal length would look like
when the depth is increased to 18, hold down the horizontal scroll bar next to the text box
and watch the parabola's shape change.
If you click the Save to Text File
button, the program will prompt you to select a folder and enter a filename, and then it writes a file with the
information you see in the text box on the right. Here's how the saved file looks when it is opened using Windows
Notepad (using the Lucida Console non-proportional
font where all characters have the same
width so the columns line up vertically). The program will automatically suggest a filename that includes depth and
diameter but you can enter any filename you like.
5. If you'd like to see the coefficients of the Equation that
describes the current Parabola, use the menu choice: File > View
the Coefficients. You will see a message box like this one showing you the values
used in the parabola equation:
6. If you move your cursor over the image of the parabola,
you will see the individual points calculated by the program: the (x, y) coordinates
are shown at the bottom of the display. The point (horizontally) closest to the mouse
cursor will be shown, you can see the location of each point listed in the text box.
There are several file output formats you can use to save
the data to a file that can be read by another program like ACAD, CorelDraw, or MS Excel.
You can see these menu choices under the File
You can print the graphic of the parabola to a printer using the Print menu choice.
You can change the foreground and background color of the Parabola graphic using the
Options menu choice.
8. Wifi Calculations for centered or offset feedhorn dishes
can be done using the Wifi Calculations menu choice.
If you'd like to read more about Solar Collectors and Solar Cooking Projects,
or about the math behind Parabolas, click the menu choice:
File > Parabola and Solar Project Websites
Click on a website and it will load into your default web browser automatically. Click the Hide
button to view the main program form again when you're finished with the web sites. A collection of these links can be found here.
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