FLDIGI Users Manual  4.0

Table of Contents

Carrier Frequency

Fldigi generates CW by inserting a keyed tone at the current waterfall audio frequency. The CW carrier frequency is the USB carrier + the audio frequency, or the LSB carrier - the audio frequency. If fldigi is tracking and receiving a CW signal on the waterfall your transmitted signal will be exactly on the frequency of the other operator. You probably cannot use your transceivers CW filter unless that filter can be used with the SSB mode.

QSK and the TAB KEY

If you are operating QSK with a separate transmitter / receiver you can very quickly stop your transmit signal with the TAB key. In the CW mode only the TAB key causes the program to skip over the remaining text in the transmit text buffer. The text that is skipped will be color coded blue. The program remains in the transmit mode (PTT enabled), but since the buffer is now empty no A2 CW signal is generated. Code transmission will then restart with the very next keyboard closure of a valid CW character.

Pausing transmit

The Pause/Break momentarily key stops sending text. Pressing it again resumes transmission.

Aborting transmit

The Escape key is used to immediately stop text transmission. The Tx buffer is cleared.

WPM adjustment

In CW mode the status bar is changed to include a transmit WPM adjuster. Use the arrow buttons or the mouse. Mouse wheel up/down changes transmit WPM by +/- 1. Hold the shift and mouse mouse wheel changes transmit WPM by +/- 10. The "*" button immediately to the right of the WPM adjuster is used to toggle between the current and the default transmit WPM.

The transmit WPM can also be adjusted with three hot keys:

The "Default" control on the CW tab sets that default value. If during a QSO you needed to slow down to give the other op a better chance to copy what you are sending, just hit the "*" on the numeric keypad and the CW code will immediately switch to sending CW at the set default value (18 wpm in this example). Press the "*" again to return to back to the CW speed that you were previously using.

Each time the transmit WPM is changed the receive decoder WPM tracking is reset to the new transmit WPM. This allows you to quickly force the decoder to a new WPM range.

The Rx and Tx WPM are shown in the status bar.

* indicates that default WPM is selected

Farnsworth keying

You might want to use farnsworth keying to provide a character rate that is faster than the word per minute rate.

Farnworth Timing

Set the F-WPM slider to tthe character rate and enable the Use Farnsworth timing check box. When the TX WPM is set to a speed below the Farnsworth value then the character rate will be at the Farnsworth setting and the word rate will be at the TX WPM rate. You can also set the TX WPM and F-WPM from within a Macros.

CW configuration

The CW Configuration is easily reached from the Config menu or by right clicking on the left most entry in the status bar (CW).


The prosigns are configurable (see CW Configuration ). The defaults are:

BT = <BT>
AA ~ <AA>
AR > <AR>
AS < <AS>
HM { <HM>
SK % <SK>
KN + <KN>
VE } <VE>

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