[Discuss-gnuradio] uhd newbee problem with B200+TCXO

[Thomas Early]

I have a new ettus B200 with TCXO (no antenna) plugged into my ZOTAC ZBOX USB3 
port running Debian 7.7. I recently built gnuradio with the build-gnuradio 
script.

I was trying to build a broadcast FM radio receiver from available examples 
and was having some problems, so I created a simple flow of UHD source feeding 
an FFT sink and I still get the sample problem. Here is my grc output:

<code>
linux; GNU C++ version 4.7.2; Boost_104900; UHD_003.008.000-52-g2068af70

<<< Welcome to GNU Radio Companion 3.7.5.1 >>>

Preferences file: /home/tom/.grc
Block paths:
        /usr/local/share/gnuradio/grc/blocks
        /home/tom/.grc_gnuradio

Loading: "/home/tom/grc/uhd-test.grc"
>>> Done

Showing: "/home/tom/grc/uhd-test.grc"

Generating: "/home/tom/grc/top_block.py"

Executing: "/home/tom/grc/top_block.py"

linux; GNU C++ version 4.7.2; Boost_104900; UHD_003.008.000-52-g2068af70

Using Volk machine: avx_64_mmx_orc
-- Operating over USB 3.
-- Detecting internal GPSDO.... Found an internal GPSDO
-- Initialize CODEC control...
-- Initialize Radio control...
-- Performing register loopback test... pass
-- Performing CODEC loopback test... pass
-- Asking for clock rate 32.000000 MHz... 
-- Actually got clock rate 32.000000 MHz.
-- Performing timer loopback test... pass
-- Setting master clock rate selection to 'automatic'.
-- Setting references to the internal GPSDO
-- Initializing time to the internal GPSDO

UHD Warning:
    get_time: ValueError: get_nmea(): no GPRMC message found

UHD Warning:
    get_time: ValueError: get_nmea(): no GPRMC message found
Traceback (most recent call last):
  File "/home/tom/grc/top_block.py", line 92, in <module>
    tb = top_block()
  File "/home/tom/grc/top_block.py", line 58, in __init__
    channels=range(1),
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/uhd/__init__.py", line 
122, in constructor_interceptor
    return old_constructor(*args)
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/uhd/uhd_swig.py", line 
1752, in make
    return _uhd_swig.usrp_source_make(*args)
RuntimeError: ValueError: Timeout after no valid message found
</code>

It seems there is a lot of discussion on "no GPRMC message found" UHD warning 
that seems to point to no GPS signal, but I was under the impression from the 
ettus.com website that a GPS antenna wasn't required for the TXCO.

Any help much appreciated.