Hi,
I am trying to use the the poly-phase clock sync.
At high S/N levels it works very well but at low S/N (<20dB S/N)
it's performance is very bad. Which probably means I have made a
mistake somewhere.
The parameters I am passing to the module to generate the mother filter are
firdes.root_rais
Hello Dinos,
As no one has answered you I will have a try.
Physically the USRP can send DVB-S and DVB-S2
the main problem may well be the symbol rate
you require to mimic the satellite transponder.
As far as Gnuradio S/W is concerned I am not
aware of anything that will do what you want at the
On 26/01/2011 19:48, Marcus D. Leech wrote:
its importing a really old gnuradio that doesnt have gr.version()
in other words, you have multiple gnuradios installed
-josh
And your PYTHONPATH likely points to the wrong version.
Yes you were both right. I have it working now. Thanks.
- Char
Hi All,
When I try running gnuradio-companion I get
File "/usr/local/bin/gnuradio-companion", line 45, in
"""%gr.version()
AttributeError: 'module' object has no attribute 'version'
Anyone know what I have done wrong?
- Charles
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When setting the kernel max buffers for UHD the manual
suggests using
sudo sysctl -w net.core.rmem_max=
sudo sysctl -w net.core.wmem_max=
I have done that on my system and it has made a huge difference to
the performance of my software. I can now transmit my DVB-T
signal continuously at 10 Ms/
Well I am glad to say my low power problem is fixed.
In the end I had to go into my uhd directory do a git pull
followed by a make and then a make install.
I now have 60 mW on 1.3 GHz.
Thanks for the help guys, especially to Jason Abele.
- Charles
http://www.g4guo.blogspot.com/
__
Does your code set the transmit gain on the WBX?
Eric
Yes to 25. I checked the range and set it to maximum.
- Charles
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- Original Message -
From: "Jason Abele"
To: "Charles Brain"
Cc:
Sent: Monday, June 14, 2010 7:03 PM
Subject: Re: [Discuss-gnuradio] WBX power level
Hi All,
Has anyone measure the power level coming out of their WBX board?
Measured on a Gigatronics 8541 m
- Original Message -
From: "Philip Balister"
To: "Charles Brain"
Cc:
Sent: Saturday, June 12, 2010 4:54 PM
Subject: Re: [Discuss-gnuradio] WBX power level
Is your flowgraph delivering the maximum amplitude to the USRP?
Philip
I am not using gnuradio I am
Hi All,
Has anyone measure the power level
coming out of their WBX board?
Measured on a Gigatronics 8541 microwave
power meter connected directly at the
back of the USRP2 I am getting (with a CW carrier)
100 MHz about 35 mW
1.3 GHz about 15 mW
Ettus quote
50 - 100 mW < 1.2 GHz
30 - 70m
3 - Measure the amplitude of the TX DC offset as received by the RX (in
this case at -1 MHz). Iteratively adjust your I TX DC offset number
until you get to the lowest power you can see. Then do the same for Q.
If it still isn't low enough, do I again.
Matt
Hi Matt,
Are the settings for
Well I have had another look at the offset stuff.
What seems to be happening is that when you apply an offset
you have to scale back the max IQ values being sent to the USRP2.
I get this situation.
No LO offset, great raised cosine shaped QPSK signal
Add LO offset, QPSK signal looks awful.
R
Hi Johnathan,
I tried an offset of 10 MHz and the output on the spectrum analyser
looks frazzled, it no longer looked clean. Funnily enough the satellite
receiver still managed to lock to the signal.
I am fiddling about with an anti aliasing filter at the moment
but when I have that sorted I wil
Hi Johnathan,
You can offset the carrier with UHD by passing a 2nd parameter
in the set_tx_freq call. Unfortunately it only seems to work with
small offsets, far too small to take it outside the passband of my
signal. :-( It was not so much of a problem with my DVB-S code
but I am now playing
Hi,
Is there any way of calibrating out or mitigating the
carrier at the WBX tx frequency? I am sending
a wideband signal and the carrier (which I assume is
due to dc coupling in the WBX) is at a significant level
compared to my signal.
- Charles
Kit USRP2 - WBX - UHD
http://www.g4guo.blog
Hi,
Sorry for the subject line but I couldn't think of what else to call it.
I have been using the UHD in my application and while adding the
facility to my GUI to transmit different symbol rates I noticed that
when I am transmitting samples and send a tx_set_rate command
strange things happen
Hi,
Well I can now find my usrp2 using uhd_find_usrps.
After sorting out how to have 2 Ethernet connections
on my PC and sending things to the right interface and
getting my firewall to play ball :-)
What I now want to do is to configure the WBX
set the interpolation ratio and then start streami
://www.g4guo.blogspot.com/
- Original Message -
From: "Tim Pearce"
To: "Charles Brain"
Cc:
Sent: Sunday, May 09, 2010 12:03 PM
Subject: Re: [Discuss-gnuradio] Which version of UHD firmware should I be using?
Charles,
If your looking to move applications to the long term solution you
Hello,
I am a bit confused, there seems to be two versions of the UHD firmware
a "Raw Ethernet version" and a "UDP version". I am about to try and move my
USRP2 application to UHD and I was wondering which version I should be
using? I have a USRP2 and a WBX board.
- Charles
http://www.g4guo.
This is what I use
http://www-users.cs.york.ac.uk/~fisher/mkfilter/racos.html
- Charles
- Original Message -
From: "Yan Nie"
To:
Sent: Monday, April 26, 2010 10:55 PM
Subject: [Discuss-gnuradio] how to decide the number of taps of RRC filter
Dear all,
I'm trying to transmit a se
Hi,
Would it be possible (now)/( or in the future) to be able to change the
sampling rate of the DAC in the USRP2 using an external clock?
I am working on stuff that is pushing what is possible in software
and not having to add extra overhead simply to do up/down
interpolation to get to somet
The problem has now been solved. I had assumed the USRP2's
DAC sample rate of 400 MS/s was the rate I had to interpolate to.
Not so, it should be 100/s MS/s.
Thanks all
- Charles
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-
From: "Brian Padalino"
To: "Charles Brain"
Cc:
Sent: Sunday, February 21, 2010 7:55 PM
Subject: Re: [Discuss-gnuradio] using sig_source_c on a USRP2
You should definitely be able to see something at 1.001GHz, but any
residual DC offset will also cause a spike at 1
not supported. The documentation is fairly sparse and even more
so on the USRP2. The USRP2 sinks don't have the same naming format
as those for the USRP1 i.e sink_32fc vs sink_c which confuses me.
- Charles
- Original Message -
From: "Brian Padalino"
To: "Ch
Hello,
I have been playing around with the USRP2, mainly to
get a feeling for how much data I can pass across the
Ethernet.
I have noticed something odd
When I use sig_source_c with a sample rate of 20 Ms/s
and a frequency of 1 MHz with the WBX board set to
1 GHz and the interpolation set t
Hello,
I am trying to write a python script which will
allow me to take some 16 bit IQ samples
from a file and write them out to my USRP2/WBX.
The background is that I am trying to implement
what has been done on here
http://www.m0dts.co.uk/datv_live.htm
but instead taking the output of g
Well I am pleased to say that the txrx_wbx.bin firmware
from Jason's git seems to work on my USRP2 - WBX combination.
These SD cards are strange, I have two identical SD cards
same manufacturer (Kingston) size etc. One works and one does
not on the USRP2. On both cards the USRP2 lights come on
I assume it will be in /releases/usrp2-bin/trunk
- Charles
We haven't posted the USRP2 firmware which supports the WBX yet. Look
for it later today.
Matt
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Hello,
I just got my USRP2 and WBX today and am trying to test it.
find_usrps finds it, and usrp2_fft.py produces a spectrum
display but when I generate a low level signal I don't see
it on the display.
I have looked at the schematic and it seems to indicate I have not
selected the antenna i
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