Video Text & ID Transmission


Video Text

Fldigi can transmit a waterfall video signal which can preceed any transmission except for CW.  It can consist of a Mode ID and or user specified text.  The video appears on the receptors waterfall display and will be right side up if the waterfall moves downward.

The video text and/or ID can be toggled on and off from the Configuration Dialog, Video tab.

If the "Xmt Mode ID" is checked the video signal for identifying the mode will preceed every  transmission.

If the "Xmt Video Text" is checked the video signal which consists of the Video Text will preceed every transmission.

The width of the video in characters can be set to 1, 2, 3 or 4 wide.  Each character takes about 72 Hz so you need to be considerate of other operators on the band.  Do not use the wide video signal unless you are certain it will not interfere with another amateur.

Here are several received waterfall video signals.  These are live captures on a local signal.


DigiPan
MultiPSK

fldigi
fldigi


The video ID can also be invoked via a macro tag.

CW identifier

You can also elect to have a CW identifier sent at the end of every transmission.  The CW identifer consists of "DE <MYCALL>" where <MYCALL> is the operator callsign entered on the Oper tab.  The speed is adjustable from 15 to 40 wpm.  The CW characteristics for the identifier are:
  1. dash / dot ratio - 3:1
  2. word / dot ratio - 7:1
  3. rise / fall times - 6 msec
  4. AFCW frequency at center of current mode
The video ID can also be invoked via a macro tag.

RSID - Reed Solomon IDentifier

Fldigi can both encode and decode Reed Solomon Identification tone bursts.  This is in accordance with the RSID specification developed for MultiPsk by Patrick Lindecker, F6CTE.  Flidig's implementation differs from that in MultiPsk in the following ways:
  • if the Wide Search Detector is NOT checked then decoding only takes place within +/- 200 Hz of the current waterfall cursor position.  You must be within the frequency vicinity of the signal transmitting the RSID code for fldigi to recognize it.
  • encoding both preceeds and trails the normal signals associated with the currently selected modem
RSID decoding is enabled by pressing the button with the label "RSID ?".  Fldigi is put into a special mode for decoding RSID patterns and no other decoding will occur until either an RSID pattern is detected or the "RSID ?" button is toggled off.

When an RSID signal is detected fldigi will immediately lock to the RSID center frequency and change it's mode of operation to the detected RSID mode.  You can choose whether fldigi searches over the entire waterfall spectrum or only within the vicinity of the waterfall cursor by toggling the "Wide Search Detector" check box.

RSID was added to fldigi primarily for use by emergency communcations users.