picMorse Keyer 3.1 (24-Dec-2012)

Morse Keyer is a software keyer that can output CW radio tones or old-fashioned telegraph sounder sounds, and drive a device via a serial port (a physical telegraph sounder/loop or ham rig). This document will hopefully be all you need to get going.

Hover the mouse over the controls on the window to get hints on what they do.

Morse Tools Discussion Group

Keyer Mode

The keyer has three modes: straight-key, semi-auto (bug), and and iambic ("squeeze") paddle. The straight key mode is simple, it produces sound in response to key or paddle presses.

The semi-automatic (bug) mode emulates a Vibroplex-type key. In this mode, both International/radio and American/telegraph code can be sent. The dit length is set via the code speed control, and is calculated for the so-called "PARIS" (or "MORSE") method for International code.

The iambic mode can be used to send only International/radio code, as it does not have the timing features needed for American Morse. The iambic mode is normally the "B" mode, which adds a trailing element if the paddle is released "early". Most people prefer this mode. Mode "A" can be selected if you're used to it. For more info on iambic keying, see Using an Iambic Paddle by Chuck Adams, K7QO and What's all this iambic keyer mode A and B stuff, anyhow? The code speed control uses the so-called "PARIS" (or "MORSE") method to establish dit and dah lengths.

Keying Inputs

The keyer can be keyed with left and right mouse buttons, or a straight key, single-level, or iambic paddle attached to a serial port (via the CTS and DSR signals). A single-lever paddle is most useful when the keyer is set for semi-automatic (bug) mode. This allows you to send American Morse code like you would with a real bug. An iambic paddle is most useful when the keyer is in the iambic paddles mode, and is limited to International Morse code.

Keying With the Mouse

To key with the mouse, you must move the cursor over the blue "mouse keying area" in the keyer's window.

Connecting a Paddle via the Mouse Inputs

If you have an old mouse you can sacrifice, consider turning it into a mouse interface for your paddles. Open the mouse and locate where the left and right button microswitches attach to the PC board. You should be able to see that one side of each switch is connected together. This is the common. The other side of each switch will be your left and right connections. The key effectively closes the mouse button switches (connected in parallel to the switches). Solder wires to the PC board so the key parallels the mouse button switches.

This is actually the best way to connect a physical key as the signals coming into the system are conditioned for debouncing and very fast to react. The disadvantage is that you must put the cursor over the keying area as already mentioned.

Connecting a Paddle via Serial Port

See the directions at Les Kerr's MorseKOB Tutorial Appendix B or at the on the MorsePowser Web Site. Once you have the cable made up, connect it, select the COM port to which it is connected. Now try keying. If you got the cable and port number right you'll be all set.

Sound Output

You can select to have radio tone or telegraph sounder output (DirectX output only). If you select Radio Tone, clicking the up and down arrow in the Tone Freq. box will play a short tone at the new frequency. You can control the rise/fall times of the raised-cosine envelope of tones as well. If you select Telegraph Sounder, you can cycle through the available sounder sounds in the same way. At speeds above 30 wpm, the telegraph sounds can start to sound mushy. This is a limitation in the speed of the sound playing in Windows. Note that telegraph sounds are not supported when you are using ASIO output (see below).

If you want to use a sound output device ("sound card") other than the one currently selected in Windows, you can select it in the dropdown list. To use the one selected in Windows, select Primary Sound Driver. In addition, if your system has a special low-latency driver that conforms to the Steinberg Audio Stream Input/Output (ASIO) protocol, you can select that as well (though telegraph sounds are not supported). The advantage of ASIO is that, for high speed sending, the delay between your keying and the audio you hear is reduced compared to that for the normal DirectX sound output. Even if your sound driver doesn't natively support ASIO, you may be able to reduce your sound feedback latency via the ASIO4ALL universal ASIO driver for WDM Audio.

Connecting an External Telegraph Sounder/Loop or Ham Rig

First you need to make up an interface circuit which uses the serial port's Request to Send (RTS) pin to control the current loop that drives the sounder or loop. You can find out more at Les Kerr's MorseKOB tutorial Appendix D. Once you have the sounder interface connected, select your COM port and click Test button. Your sounder should click/clack 4 times or your ham rig should send 4 dits. If this works, you're all set. Check the Use box. When the serial port is active, the keyer always keys the DTR pin whether or not you have anything hooked up to it! If you don't want the keyer to make sounds, just turn the volume down to zero.


Morse Keyer was developed by Robert B. Denny. You can contact me at rdenny@dc3.com.

Thanks to Les Kerr, the MorseKOB author, and John Samin, author of CW Communicator, for help in getting this and other Morse code tools going. Please note that John Samarin, author of CW Communicator, has retired from supporting the program. However, a gent from Portsmouth England has put up a great CWCom support site called MorsePower.

As shown below, Morse Keyer is licensed as open source. Sources are available at the Morse Code RSS News Tools SourceForge Project.

picRSS Morse by Robert B. Denny is licensed under a Common Public Attribution License.