This was submitted by a user at Linux in the Ham Shack. I have not tested this myself but it appears to be correct.

How to build fldigi on Ubuntu 9.10 X64

regards

k6***

1: get source tar balls
# cd /usr/local/src
# sudo bash
# [sudo] password for hamradio:
# root@hamworkstation:/usr/local/src#

Browse to http://www.w1hkj.com/Downloads.html
Copy link of source tar ball.
Paste link into root shell with the wget command.

# wget http://www.w1hkj.com/fldigi-distro/fldigi-3.11.5.tar.gz
# enter
Extract tar ball
# tar -zxf fldigi-3.11.5.tar.gz

Browse to http://hamlib.sourceforge.net/download.html
Copy link of source tar ball.
Paste link into root shell with the wget command.

# wget http://downloads.sourceforge.net/hamlib/hamlib-1.2.8.tar.gz
# enter
Extract tar ball
# tar -zxf hamlib-1.2.8.tar.gz

2: Get Software Dependencies
# apt-get install libxml2-dev tcl libfltk1.1-dev libxmlrpc-c3-dev pulseaudio libpulse-dev portaudio19-dev libsndfile1-dev libpng12-dev libjpeg62-dev

3: Building hamlib
# cd hamlib-1.2.8
# ./configure
# make
# make install

Test run hamlib rigctl with the settings for your radio.

# /usr/local/bin/rigctl

4: Build fldigi

# cd /usr/local/src/fldigi-3.11.5
# ./configure
# make
# make install

5: Run fldigi

Open new terminal shell hamradio@hamworkstation:~$

# /usr/local/bin/fldigi

Have fun and good luck

P.S.
Check your paths.
/usr/bin/fldigi will be a different version then /usr/local/bin/fldigi