CW KEYER

The HF beacon on balloon system used a continuous wave (CW) keyer.

DOWNLOADING THE KEYER

The CW keyer schematics can be downloaded as a zipped file, cwkeyer.zip (8 KB) from this UMARS site. The file is in the PADS format.

DOWNLOADING THE PADS CAD PROGRAM

The CW keyer schematic is in an old Mentor Graphics PADS computer-aided design (CAD) format (originally established by Racal-Redac in 1985) designed for the MS-DOS operating system. It is here for historical reasons only. Today, there are many sophisticated printed-circuit board (PCB) software packages (e.g., Cadence, Orcad, Viewlogic/Mentor, PADS, Pcad and Protel, Autocad, CADSTAR, Circuit Creator, Circuit Maker, Electronic Work Bench, EZ-Route, or Tango Logic) for all the platforms and operating systems. For example, the Free PCB imports and exports PADS-PCB netlists (i.e., the list of parts and their connection points in a circuit). There are also Windows-based PADS packages.

The following three zipped files can be downloaded from the Department of Electrical Engineering, University of Nebraska at Lincoln.

• PADSL Logic (1.08 MB) schematic editor (as zipped file padslog.zip).
• PADSL PCB (1.03 MB) layout program (as zipped file padspcb.zip).
• PADSL Libraries (488 KB) a collection of files and programs that both of the above use (as zipped file padslib.zip).

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