Re: [Discuss-gnuradio] USRP2 + WBX: Unable to receive FM signals

[Elvis Dowson]

Hi,
       I modified the usrp_decimation to 210, which gives me an ouput of 476190 
Hz for the audio sample output. This was the closest I could get it to work at 
48KHz. 

I still get broken FM audio output, and I constantly get the audio buffer 
under-run aUaU messages on the console. 

Could someone please help me get the correct FM receiver output settings? 

I'm using the following command line parameters to start the program:

./usrp2_wfm_rcv.py -e eth2 -f 104.4 -V 0.0 -g 31 -O hw:0,0


Here is a patch of the modifications that I've made to the script so far:

diff --git a/gnuradio-examples/python/usrp2/usrp2_wfm_rcv.py 
b/gnuradio-examples/python/usrp2/usrp2_wfm_rcv.py
index 1783660..84b7ef9 100755
--- a/gnuradio-examples/python/usrp2/usrp2_wfm_rcv.py
+++ b/gnuradio-examples/python/usrp2/usrp2_wfm_rcv.py
@@ -69,11 +69,12 @@ class wfm_rx_block (stdgui2.std_top_block):
         self.u = usrp2.source_32fc(options.interface, options.mac_addr)
 
         adc_rate = self.u.adc_rate()                # 100 MS/s
-        usrp_decim = 312
+        usrp_decim = 210
         self.u.set_decim(usrp_decim)
         usrp_rate = adc_rate / usrp_decim           # ~320 kS/s
         chanfilt_decim = 1
         demod_rate = usrp_rate / chanfilt_decim
+       print "demod_rate = %d" % (demod_rate)
         audio_decimation = 10
         audio_rate = demod_rate / audio_decimation  # ~32 kHz
 
@@ -87,7 +88,8 @@ class wfm_rx_block (stdgui2.std_top_block):
                 dbid == 0x0040 or #usrp_dbid.TV_RX_REV_3
                 dbid == 0x0043 or #usrp_dbid.TV_RX_MIMO
                 dbid == 0x0044 or #usrp_dbid.TV_RX_REV_2_MIMO
-                dbid == 0x0045 ): #usrp_dbid.TV_RX_REV_3_MIMO
+                dbid == 0x0045 or #usrp_dbid.TV_RX_REV_3_MIMO
+               dbid == 0x0053 ): #usrp_dbid.WBX
             print "This daughterboard does not cover the required frequency 
range"
             print "for this application.  Please use a BasicRX or TVRX 
daughterboard."
             raw_input("Press ENTER to continue anyway, or Ctrl-C to exit.")


Elvis Dowson