Using a well-known circuit, I show you how to build a simple computer interface so your logging software can send CW through your radio.
The logging software simulates someone using a straight key. It changes the voltage on an RS-232 pin and the electronic circuit uses a transistor as a switch, grounding the lines as though someone grounded the contacts of a straight key.
This interface will let you work a contest or pile-up using your logging software – without having to use a key or paddle.
The circuit diagram: http://www.n3fjp.com/cwschematic.html
N3FJP website: http://www.n3fjp.com
Tripp-Lite USB to Serial Converter: See it on Amazon.com
6 thoughts on “Build a Computer to CW Interface”
Here is a similar diagram that allows Elecraft KX2 or KX3 operation of both CW keying and rig Control http://www.k8zt.com/KX3__N1MM_interfaces.jpg
Thank you, Anthony! – Cliff
Hey Cliff. I know this video was 6 years ago but I have a few questions about the interface. I know you are probably busy so any help you can give would be appreciated.
I am trying to setup an old Swan radio for CW. The problem is I don’t know morse code and even if I did, I can’t hear well enough to decode. Question: Does this interface (with the software) decode incoming CW? Also, have you upgraded the interface with the FTDI board someone mentioned in the comments? With an older radio, is more than the connection to the key jack required?
Again, I know you must stay very busy but, I was hoping that you could answer my questions before I try to make the interface and it not work the way I hope it does.
Bobby, this interface will NOT help you to decode CW. It is simply a circuit that will allow your computer to emulate a straight key in order for the computer to send CW. It’s sort of like an electronic ghost sitting at your straight key, pushing down on the lever to close the electrical contacts for you. Software controls when the contact is closed and for how long. – Cliff