cocoaNEC 2.0 Reference Manual
Input Interfaces

Kok Chen, W7AY [w7ay (at) arrl (dot) net]
Last updated: January 10, 2012

cocoaNEC Input Interfaces

The NEC-2 engine expects antenna geometry (wires, surface patches, etc) and control input (loads, excitation voltages, frequencies, etc) in the form of a Hollerith "card deck." Each "card" consists of a text line of up to 80 characters. The card formats are defined in the Program Input section of the NEC-2 documentation.

The NEC-4 card formats are mostly the same as NEC-2. NEC-4 has cards that do not appear in NEC-4 and certain card, such as the GH card, has a very different format as the original.

There are two methods in cocoaNEC to convert user antenna models into a NEC-2 card deck. One of these methods consists of a tabular style input, where antenna geometries are defined with a spreadsheet. The second of these two methods is a C-like interpreter (called NC) where geometries are described with formulas. There is a third input method in cocoaNEC, a direct card deck input, including a card editor.

The second section of the Reference Manual describes the spreadsheet model in more detail, and the third section of the Reference Manual describes the NC interpreter model in more detail.

(Please note that the spreadsheet method has been deprecated in favor of the NC interpreter because of the versatility of the latter. No new functions will be added to the cocoaNEC spreadsheet interface.)


File Menu

The cocoaNEC File Menu is used to open and save the antenna models..

Figure 1-1 File Menu

The menu items in the top group of the File Menu are used to open spreadsheet models. The menu items in the second group are used to open NC models, and the File menu items in the third group are used to open files that are written as NEC-2 "Card Decks."

The Save and Save As... menu items are common to all three input interfaces. When Save or Save As... is selected, the antenna model in the currently active window will be saved to a file. The default file extension for a spreadsheet model is ".nec", the default file extension for an NC file is ".nc" and the default file extension for a card deck is ".deck".

You can convert a spreadsheet model or an NC program into a NEC-2 card deck by using the Export Card Deck... . Like cocoaNEC, many other antenna programs are able to accept NEC-2 card decks.

The Close (Command W) menu item will close the active model window.

In addition to displaying antenna data that are generated from a cocoaNEC workflow, cocoaNEC's Output Window can also display graphical data that are created by other programs as long as those programs can produce the nec2c or NEC-4 output ("line printer") formats:

Figure 1-2 Opening NEC Line printer Format

Next: NEC Engines
Back to: Reference Manual