A CW Keyer using the comports RTS or DTR line to key CW.
Terminated at the radio end with a 3.5mm stereo jack.
If your radio requires a 1/4" jack use a simple 3.5mm to 1/4" adaptor.

Extremely effective
Can be configured to key using either the RTS or DTR line and so will operate with any CW keying software.

 

 

DID YOU KNOW;
A lot is made about timing issues with Windows not allowing access to the serial ports directly...
On a modern PC timing power saving issues are what causes any such problems, Windows is constantly turning things off, then back on again when they are needed, this produces a "time lapse".
Anyhow, in Windows XP, if you want to change the way your PC (and laptop) looks at ports (serial, parallel, etc), simply open device manager, click on Computer, click on ACPI Multiprocessor PC, (or whatever your PC is shown as such as Pwer saving PC etc), double click on that entry, select update driver, select Install from specific location, click next, click Don't search, click next, then from the list select "Standard PC", click next, windows will then alter the way it uses the PC and any timing issues that you have had will now be resolved.