Problem with RFX1800: "No class defined to handle daughterbo


I have an USRP rev4 and tried to use the RFX1800 tranceiver with
the example program under Ubuntu on a PC. My CVS / SVN
checkout is two or three days old. I own a RFX2400 tranceiver, too.
The RFX2400 works out of the box, but if I plug the RFX1800 on the
USRP I only get this error message:

martin@sigint:~/gr-build/gnuradio-examples/python/usrp$ sudo python -R A
Traceback (most recent call last):
File “”, line 252, in ?
main ()
File “”, line 248, in main
app = stdgui.stdapp(app_flow_graph, “USRP O’scope”, nstatus=1)
File “/usr/local/lib/python2.4/site-packages/gnuradio/wxgui/”, line 36, in init
wx.App.init (self, redirect=False)
File “/usr/lib/python2.4/site-packages/wx-2.6-gtk2-unicode/wx/”, line 7473, in init
File “/usr/lib/python2.4/site-packages/wx-2.6-gtk2-unicode/wx/”, line 7125, in _BootstrapApp
return core.PyApp__BootstrapApp(*args, **kwargs)
File “/usr/local/lib/python2.4/site-packages/gnuradio/wxgui/”, line 39, in OnInit
frame = stdframe (self.flow_graph_maker, self.title, self._nstatus)
File “/usr/local/lib/python2.4/site-packages/gnuradio/wxgui/”, line 60, in init
self.panel = stdpanel (self, self, flow_graph_maker)
File “/usr/local/lib/python2.4/site-packages/gnuradio/wxgui/”, line 81, in init
self.fg = flow_graph_maker (frame, self, vbox, sys.argv)
File “”, line 82, in init
self.u = usrp.source_c(decim_rate=options.decim)
File “/usr/local/lib/python2.4/site-packages/gnuradio/”,
line 243, in init
self.db = (db_instantiator.instantiate(self._u, 0),
File “/usr/local/lib/python2.4/site-packages/gnuradio/”, line 31, in instantiate
raise ValueError, “No class defined to handle daughterboard
(dbid = %d)” % (dbid,)
ValueError: No class defined to handle daughterboard (dbid = 48)

How can I fix it?