Fldigi
offers several ways to identify the operator or mode that is being
used. This is particularly useful when using a hard to recognize
mode such as Thor, Olivia or MT63.
Video Text
Transmitted
video text will appear as a sequence of characters on the waterfall.
The text can be a brief mode identifier or some user specified
text. You can use a small font that always appears as a 2
character wide sequence or a larger font that can be 1 to 4 characters
wide. You should be aware that the video signal is a constant
energy signal and the content will be spread across multiple
characters. The highest s/n at the receiving end will be for 1
character wide video. Small font at 2 character width is next in
s/n performance followed by 2 character large font etc. You can
select which modes will include the video text preamble. You can
limit the horizontal (frequency width) of the video signal in one of
several inclusive ways.
- Number of characters per row of text
- Constrain to be less than or equal to 500 Hz
- Constrain to be within the bandwidth limits of the mode in use
Fldigi uses abbreviated acronyms for the mode and it's characteristics
when you are transmitting the mode ID using a video text. Here
are two examples, one in small and the other in large font.
Notice that Olivia 16-500 is abbreviated to OL-16/500 and that the
number of characters is limited to 8 per row. You might want to
use the large characters by default if you routinely have QSO's with
operators using older digital mode programs or one whose waterfall
visual is not on a par with fldigi's.
Cw postamble
You
can transmit your callsign in CW as a postamble to all modes except of
CW (a bit redundant to do that). You can select which modes will
include the cw postamble.
Reed Solomon Identifier
RSid,
Reed
Solomon
Identifier,
is a special transmission designed by Patrick Lindecker, F6CTE, for the
modem program MultiPsk. It has been adapted to other modem
programs. Fldigi's implementation is compatible with the MultiPsk
RSid, but provides a slight variation. You can transmit RSID at
both the beginning and end of a transmission. The detection of
RSid normally only occurs
in the near vicinity of the current waterfall tracking point.
This cuts down on extraneous RSid detections when the band is
crowded and several RSid signals might be present. If you want
fldigi to search the entire waterfall for RSid signals you can do so by
enabling the "Detector searches entire passband". You start the
search for a
signal based on RS Id by using the main panel switch. The RSID
detector is a separate decoder that operates in parallel with all other
modem decoders. If you select the "Mark previous frequency and
mode" a restore link will be inserted into the Rx text upon detecting
an RSID signal. Clicking on this link restores the previous
frequency and mode of operation. You elect to disable the RSID
upon first detection. You also have the option of just receiving
notification when an RSID signal is detected. The notification
occurs with a pop-up message box.
You can select which modes will include the transmitted RS identifier,
and which modes will react to a received and decoded RS identifier.
The mode to identifier relationships are selected by pressing the associated "modes" button.