On the Design News Forum, there is a thread on inexpensive schematic capture software. They list the following:
- DesignWorks. At $500, this hardly qualifies as “low cost,” at least not for radio amateurs.
- Smartdraw. At $200, this package is still pretty expensive.
- pcb123. This package is freeware. You can’t get any cheaper than that.
- TinyCAD. This package is open source, so it’s not only free, but if you really wanted to modify the code for your own purposes, you could do so.
- For Linux/Unix users, bpaddock listed the following:
One guy also noted that he uses the drawing tools that come with Microsoft Word to draw schematics.