On 4/30/24 21:40, Gary Schafer wrote:
Sorry about my misunderstanding. I recreated a portion of your flowgraph
just to see what it would do. I left the 16 kHz sample rate but with a
2^15 time record size. Once I ran the flowgraph, it was 17.5 seconds
before the Number Sink updated, and 34 seco
On 4/30/24 18:35, Gary Schafer wrote:
"I need data points at convenient intervals for time series plotting,
e.g., 512 samples/second going into a 512 bin FFT to provide one maximum
amplitude value per second."
Let me answer that one at the same time as "Ultimately I want to plot
both the amp
Hi Gary --
Thanks for getting back to me. Maybe I can explain better what I'm
doing. The data is 16 ksps complex IQ centered at 50.080 MHz. The
target signal is an essentially unmodulated CW carrier about 427 below
that. I have about 8 hours of recorded data to analyze.
Ultimately I want
I am reading Digital RF data at 16k samples/second, and my goal is to
get the power of the maximum frequency once per second.
I start by resampling to a power-of-two rate, then translating to move
the desired frequency to the center with further decimation, then doing
an FFT, converting to log
By the way, I was using the Digital RF Channel Source block to read HDF5
data files. That block automatically throttles at the rate in the HDF5
metadata. The alternate "Digital RF Source" block has a throttle
parameter, but it seems to work backwards -- when set to true, it
doesn't throttle a
On 4/10/24 11:29, Fons Adriaensen wrote:
Both the decimation and 80 size 1024 FFTs per second should be peanuts
for any modern PC...
And of course you don't need to do the FFT again for every sample,
it just generates a lot of redundant data.
I understood that if you have a 1024 bin waterfall
I want to make waterfall displays of narrow bandwidth signals -- say +/-
20 Hz with FFT depth of 1024. Decimating to ~80 samples/second and
feeding that into a 1024 bin FFT is... not fast.
What's the best way to record the FFT vectors to speed up the display
for later analysis? What blocks w
peak imaginary negative = -0.821772
peak real positive @ 1703752736, peak imaginary positive @ 1624430697
peak real negative @ 1846543928, peak imaginary negative @ 2753521145
Ron
On 5/17/22 12:44, John Ackermann N8UR wrote:
Hi --
I have broadband HF data recorded off the air (ham radio bands 384
Hi --
I have broadband HF data recorded off the air (ham radio bands 384 kHz
wide) and am trying to figure out what sort of gain settings I need to
play it back on a USRP without distortion. My worry is the way multiple
fairly strong signals could add together in phase to create momentary
sp
There is some magic involved in shrinking a RPi image so that it will
then expand when reinstalled, like the original Raspbian. I went
through the pain a while ago and documented it here:
https://blog.febo.com/?p=283
John
On 5/8/19 12:45 PM, Philip Balister wrote:
> On 05/08/2019 12:09 PM,
That's great! Thanks, Ron!
On 3/17/19 3:30 PM, Ron Economos wrote:
I have a block that does what you need.
https://github.com/drmpeg/gr-iqlevels
Ron
On 3/17/19 08:09, John Ackermann N8UR wrote:
I'm working on a flowgraph that generates an output waveform about 375
kHz wide with
On 3/17/19 3:45 PM, Kevin Reid wrote:
If you want to detect clipping, you want to know if the magnitude of any
sample is greater than 1.0 — that's all there is to it. No FFT. My code
happens to divide the stream into vectors but that is the only similarity.
Performing a FFT will not help you
On 3/17/19 3:01 PM, Kevin Reid wrote:
One of the AGC blocks that has separate attack and decay rates (agc2_cc
or agc3_cc) could be used to do this: set attack to 1, decay to 0,
ignore the output, and read (1.0 / agc.gain()) to find the peak-hold
magnitude.
In my own application, I am using t
On 3/17/19 12:55 PM, Marcus D. Leech wrote:
On 03/17/2019 11:09 AM, John Ackermann N8UR wrote:
I'm working on a flowgraph that generates an output waveform about 375
kHz wide with very high peak-to-average power -- at least 20 dB. This
is sent into a USRP1 with BasicTX board to genera
I'm working on a flowgraph that generates an output waveform about 375
kHz wide with very high peak-to-average power -- at least 20 dB. This
is sent into a USRP1 with BasicTX board to generate an output at 29 MHz.
I'd like to show in the flowgraph GUI the peak instantaneous output
level, to h
>compiling.
>
>On Mon, Oct 29, 2018 at 2:56 PM Ron Economos wrote:
>
>> It's probably checking out the wrong version of GNU Radio and/or
>VOLK.
>> These days, you need to checkout the maint-3.7 branch and do a
>submodule
>> update.
>>
>> git
agnose.
John
On 10/29/18 3:49 PM, John Ackermann N8UR wrote:
On Mint 19 (and presumably Ubuntu 18.04), you can do "sudo apt-get
install python-setuptools". Maybe that should be added to the package
check step. You can also do "sudo apt-get install python-pip" to
in
you
there directly.
I'm now rerunning the script.
BTW, this install is on a fresh Mint 19 with no development stuff
pre-installed, so there shouldn't be anything weird in my setup.
John
On 10/29/18 1:28 PM, Marcus D. Leech wrote:
On 10/29/2018 11:18 AM, John Ackermann N8UR wro
Well, this was unexpected... I got a failure in the UHD build phase:
UHD build apparently failed
Exiting UHD build
I just re-ran with logging turned on; the results are in the attached
build-gnuradio.log.gz file.
On 10/29/18 10:59 AM, John Ackermann N8UR wrote:
Hi Marcus --
I did as James
Well, this was unexpected... I got a failure in the UHD build phase:
UHD build apparently failed
Exiting UHD build
I just re-ran with logging turned on; the results are in the attached
build-gnuradio.log.gz file.
On 10/29/18 10:59 AM, John Ackermann N8UR wrote:
Hi Marcus --
I did as James
on to track all the distribs
and do the recipes myself.
If simply bypassing that check works, let me know, and I can update the
script
On 29 October 2018 at 07:11, John Ackermann N8UR <mailto:j...@febo.com>> wrote:
Thanks, Neel! However, I just downloaded the version o
ntained on GitHub.
https://github.com/ccera-astro/build-gnuradio
--Neel Pandeya
On 29 October 2018 at 07:04, John Ackermann N8UR <mailto:j...@febo.com>> wrote:
I'm trying to run the current build-gnuradio.sh script from
sbrac.org <http://sbrac.org> on a Linux Mint
I'm trying to run the current build-gnuradio.sh script from sbrac.org on
a Linux Mint 19 machine and the script immediately fails, saying "Your
Mint release must be at least Linux Mint 11 to proceed"
Is it safe to just bypass that check, or is there some sort of
incompatibilty with v19? Or is
I'm setting up a measurement program to look at the channel power inside
and outside a defined bandwidth centered at zero. The idea is to get
the ratio of the power within a low pass filter (nominally 500 Hz), and
the power in the rest of the spectrum (192 kHz) with that same 500 Hz
chunk notc
so this patch is fixed at two places, but at least it shows what needs
to change to work. (I'm also not sure if this broke things for an
integer rather than float input.)
John
On 03/06/2018 10:41 AM, John Ackermann N8UR wrote:
I must now reflect and ponder to wisely choose my pat
On 03/06/2018 10:41 AM, John Ackermann N8UR wrote:
I must now reflect and ponder to wisely choose my path. All options suck.
I'd actually like most to go back to the build-gnuradio script but I
haven't been able to verify that the issue I had last summer was
addressed -- I don&#
dio; mkdir build; cd build; cmake .." and finally
"make -j8; make install"
as well as to recompile anything that uses GNU Radio, and never to
install Ubuntu's GNU Radio again, lest you want to end up in conflict
hell.
Best regards,
Marcus
On Tue, 2018-03-06 at 09:07 -0500,
urce
code and API change, so it'll require recompilation of GNU Radio and
relinking of everything that use gr-qtgui. Does that help you?
Best regards,
Marcus
On Mon, 2018-03-05 at 16:36 -0500, John Ackermann N8UR wrote:
I hate to put such a dumb question to the list, but I'm going nuts
tryi
I hate to put such a dumb question to the list, but I'm going nuts
trying to do something that ought to be simple.
I am using a QT Number Sink to display dB values in float format. It is
showing many more decimal places than have any meaning. I'd like to
round the display to one or two decim
at worked
just fine. Without the multiplication, I think the very low level (-100
dB range) stuff was lost in the conversion.
John
On 01/07/2018 06:19 PM, Andy Walls wrote:
From: John Ackermann N8UR
Date: Sun, 7 Jan 2018 16:59:32 -0500
I need to output IQ data from a Gnuradio script i
I need to output IQ data from a Gnuradio script in 2-channel WAV format
using integer rather than floating point, as required by the target program.
Starting with a complex stream, is there a trick in GRC to output
integer WAV data? I think I recall a reference to doing a "mult const"
but Goo
-> M < N outputs with
mapping, and the reverse. I'm happy to share if you'd like to try them
out. Cheers! - MLD
On Mon, Dec 4, 2017, at 10:54 AM, John Ackermann N8UR wrote:
I find the documentation about PFB channel mapping to be confusing.
I've extracted it below.
The first pa
I find the documentation about PFB channel mapping to be confusing.
I've extracted it below.
The first paragraph seems to say the channel map has to have as many
elements "M" as the number of outputs "N".
But the second and third paragraphs talk about cases where M < N, and
only "M out of N
55 PM, John Ackermann N8UR wrote:
My current project is analyzing the strength of signals in each channel
of the AM broadcast band from a recording made during the recent solar
eclipse. The goal is to see if the eclipse caused propagation changes
leading to additional stations "popping up&q
My current project is analyzing the strength of signals in each channel
of the AM broadcast band from a recording made during the recent solar
eclipse. The goal is to see if the eclipse caused propagation changes
leading to additional stations "popping up" out of the noise. Thanks to
help fro
Thanks, Sylvain!
On 12/01/2017 11:19 AM, Sylvain Munaut wrote:
By convention, FFT sizes seem to be powers of 2. And Gnu Radio Companion
throws an error if you try to set a size of 16384 -- but will accept 16383.
Probably related to the size of the buffers or something like that.
Is using a
error does GNU Radio throw (that's the critical piece of info!)..
There's no restriction of FFT sizes.
Best regards,
Marcus
On Thu, 2017-11-30 at 14:28 -0500, John Ackermann N8UR wrote:
By convention, FFT sizes seem to be powers of 2. And Gnu Radio
Companion throws an error if you try t
Thanks! The mailing list seems to have been clogged up overnight, so
after posting I did some experiments and found that an FFT of 100 bins
to match 100 samples/second worked just fine and gives me exactly what I
want -- nicely spaced results at 1 second intervals.
On 12/01/2017 11:19 AM, Syl
By convention, FFT sizes seem to be powers of 2. And Gnu Radio
Companion throws an error if you try to set a size of 16384 -- but will
accept 16383.
In some cases, I'd like to match FFT size to sample rate. For example,
with a 100 sample/second rate, I'd like to use a 100 bin FFT to
(hopefu
On 11/30/2017 02:08 PM, Müller, Marcus (CEL) wrote:
[ snip ]
You can do that (obviously, it works!), but I'd recommend you just use
a channelizer with N=125 instead of 117! Your channel map can be used
to ignore the channels you don't need (which seem to be the 4 upper and
lower "edge" ones),
And the resampler did the trick. Carriers are now nicely aligned. Thanks
again!
On Nov 29, 2017, 4:48 PM, at 4:48 PM, John Ackermann N8UR wrote:
>Hi Marcus --
>
>First, thanks for catching the typo in the channel map. There was no
>plan to skip any channels; the goal is to get
0 0 0 0 0 0 117
0 0 0 0 0 0 0 ]
through a length=117*8 IFFT, and push the result (after a vector-to-
stream) through your channelizer. You should see single tones in all
your channels. (The different amplitudes might help telling them
apart). Do they end up in the center of your bins?
Best re
On 11/14/2017 02:20 PM, Marcus D. Leech wrote:
My real question is whether it's safe to assume that a flowgraph is
entirely clocked by the samples from its hardware source, and
consequently that processing within the flowgraph (e.g., oscillator
and mixer for tuning) does not introduce potentia
What is the clock source for a Gnuradio "internal" source such as the
Signal Source block? If there is no hardware device connected, is the
block ultimately driven by the PC clock?
Then, if there is a hardware source (SDR) as well as an internal source,
does the hardware source provide the ma
OK, bummer but thanks for the clarification.
On 11/02/2017 01:58 PM, mle...@ripnet.com wrote:
For the most part, decimation cannot be changed at runtime, due to the
way the scheduler does static allocation and buffer management.
On 2017-11-02 13:05, John Ackermann N8UR wrote:
I'm ge
I'm getting ready to do a Gnuradio tutorial for a local group, and want
to show the impact of decimation and filtering. I created a QT Gui
Range parameter that sets the ID "decimation".
In the low pass filter block I the decimation value is set to
"decimation." That seems to work and I can s
For what it's worth --
This isn't a brand-new problem. I reported it here and on the
osmocom-sdr list[1] back in June. There were responses on the osmocom
list, none that resolved the problem, and I never was able to fix it myself.
I suspect it's related to the addition of the seemingly-inn
I am trying to figure out the "frame rate" as used in log_power_fft and
"update period" used in the QT GUI sinks.
I'm trying to generate one output from both QT waterfall and
log_power_fft every 60 seconds. I've tried setting the "frame rate" in
log_power_fft to both 60 and the reciprocal 0.0
I am working with a large and long (8 hour) data set. My goal is to
show changes in propagation over time -- in particular, further analysis
of my solar eclipse RF captures.
I want to show the whole 8 hours on a the waterfall without scrolling,
which means I need to write a line to the displa
As part of the HamSci (http://hamsci.org) solar eclipse experiment I
recorded a bunch of IQ data from HF radio during the eclipse, using
Gnuradio (plus the gr-hpsdr and gr-digital_rf modules) for all signal
processing.
A Red Pitaya running at 2.5 Msamples/sec recorded the entire AM
broadcast
wrote:
On Sun, Aug 6, 2017 at 1:57 PM, John Ackermann N8UR <mailto:j...@febo.com>> wrote:
I also have a QT Frequency Sink as eye candy, and notice that its
display is about 6dB different than the Log Power FFT output. I can
think of a number of reasons why that could be, but my
I'm doing a simple flowgraph to determine the peak value (dBFS) within
an FFT. The Log Power FFT sends vectors to a Max block which outputs
the result -- it seems to be working reasonably well.
I also have a QT Frequency Sink as eye candy, and notice that its
display is about 6dB different th
. Leech wrote:
That change has been made to the build-gnuradio git repo
Sent from my iPhone
On Jun 23, 2017, at 5:29 PM, John Ackermann N8UR wrote:
For at least the last couple of days, the build-gnuradio script has been failing almost
immediately after it starts fetching, claiming that it "
Should have done this first, but I went to git.gnuradio.org with my
browser and got a "bad certificate" error. The cert is valid for a
number of gnuradio.org sites, but not git.gnuradio.org.
John
On 06/23/2017 05:29 PM, John Ackermann N8UR wrote:
For at least the last coup
For at least the last couple of days, the build-gnuradio script has been
failing almost immediately after it starts fetching, claiming that it
"could not find gnuradio/gnuradio-[core,runtime] after GIT checkout."
I changed the URL in the script from git.gnuradio.org to github.org and
that work
I just did "build-gnuradio" on a new machine and am getting a failure in
the rtl_build function that wasn't present previously.
In rtl_source_c.cc, line 224, the build fails with:
error: 'rtlsdr_set_bias_tee' was not declared in this scope
ret = rtlsdr_set_bias_tee(_dev, bias_tee);
Any sugg
I spent some time fiddling with the OP25 P25 trunking scanner software,
and with a lot of help from the guys on the op25-dev mailing list got it
working pretty well. The "how to get it to do something useful" part
isn't too well documented, so I thought I would document the config
steps and fi
owever, you're asking about resampling: Well, resamplers do exist :) !
We've got a totally different problem, though: To resample properly,
you'd need to know (or better: estimate) the clock error.
On Wed, Jun 7, 2017 at 2:47 AM, John Ackermann N8UR mailto:j...@febo.com>> wrote:
Hi Benny --
As I mentioned in another message, I'm struggling with the RF-audio
interface now. Do you have any example code for your suggestion that I
might play with (in my mind, the idea would be an "audio synchronizer"
block that would take input at the nominal audio rate and output at the
I don't have a view whether an audio synchronizer (is that the right
term?) is appropriate for GSoC, but it's a problem that's biting me
right now. I'm doing a multi-channel nbfm receiver with a polyphase
channelizer that feeds a bunch of power squelch/nbfm demod blocks, with
the audio streams
I've started experimenting with the bus port capability, using 3.7.11.1.
The QT GUI Frequency Sink creates a bus with one more port than the
number required (possibly a hidden message port). This was reported as
a bug last year, and still seems to be a problem. Is a fix for this on
the horiz
is 0, the lowest
channel is nchannels/2 + 1 or so... I think your mapping could have 4 on
the end to get the whole sequence.
On Fri, Jun 2, 2017 at 11:25 AM, John Ackermann N8UR mailto:j...@febo.com>> wrote:
Is there a basic rule for how to assign channel numbers to the PFB
channelizer
Is there a basic rule for how to assign channel numbers to the PFB
channelizer output? I seem to be too dense to figure it out from the
docs. I just want to pull the channels out in order of their RF
frequency, low to high.
I currently have a 7 channel channelizer which seems to work properl
I'd like to have an indicator in the GUI (just a small circle is fine)
light up when a Power Squelch block opens -- basically, an "in use" signal.
Is there a Qt widget that can do that, and is there a way to probe the
Power Squelch for its state? (I'd like to do this within GRC if possible.)
at did you use as argument for
firdes.lowpass()?)
Best regards,
Marcus
On 05/24/2017 04:38 PM, John Ackermann N8UR wrote:
Here's the whole flowgraph.
Once I get the code functioning, I'm planning to clean this up, maybe
add a few more channels, and make it easier to customize -- so
se, using a higher sampling rate might make
>the problem more manageable. If you'd share the first half of your flow
>graph, we could discuss options for that!
>
>Best regards,
>
>Marcus
>
>[1] http://gnuradio.org/blog/buffers
>
>
>On 23.05.2017 22:04, John Ack
#x27;t allow that choice.
John
On 05/23/2017 02:51 PM, Kevin Reid wrote:
On Tue, May 23, 2017 at 11:31 AM, John Ackermann N8UR mailto:j...@febo.com>> wrote:
I'm continuing to work on a multi-channel NBFM receiver using the
polyphase filter. I have the basic system workin
I'm working on a flowgraph that has a lot of blocks (sets of identical blocks
for 16+ channels).
What's the best way to manage this on-screen in GRC? Can GRC handle multiple
sheets, or is there a way to group a bunch of blocks into a "superblock" that
shows in the flowgraph as a single block?
Still working with the polyphase channelizer program. While everything
"works", there is something very strange: the output amplitude slowly
drops the longer the program runs. As near I can tell, this happens in
or following the frequency translating FFT block.
To test, I stripped the flowgr
I've put a short video of my tweaked version of Chris' NOAA radio
channelizer demo on Youtube at: https://youtu.be/mTUSVNdCxa4
The screen capture didn't get the drop-down box when I changed channels,
but if you look at the upper-left corner you'll see the channel change
every few seconds.
I
cleaned things up. Revised .grc file attached.
John
On 08/08/2015 02:56 PM, John Ackermann N8UR wrote:
I am playing with a slightly modified version of Chris Kuethe's
channelizer example for NOAA radio stations (my version attached). I'm
using 3.7.6.1.
The program runs just fi
I am playing with a slightly modified version of Chris Kuethe's
channelizer example for NOAA radio stations (my version attached). I'm
using 3.7.6.1.
The program runs just fine for the first 20-30 minutes on my I7-4710HQ
laptop. System monitor shows typically one core running at about 50%
w
It might be helpful to clarify that since this is a voltage ratio, it's
20log rather than the 10log used for power (e.g., doubling voltage is
6dB, doubling power is 3dB), so the scaling will look different than a
typical spectrum analyzer. (It would be nice if the instrumentation
blocks could
Thanks!
On 08/02/2015 03:11 PM, Chris Kuethe wrote:
That's because of the first LPF - I made it kind of tight. If you
change it from noaa_band_width to oversampled_width, that droop goes
away.
On Sun, Aug 2, 2015 at 12:06 PM, John Ackermann N8UR wrote:
One more thing -- it appears tha
n Sun, Aug 2, 2015 at 2:18 PM, John Ackermann N8UR mailto:j...@febo.com>> wrote:
Hi Chris --
Using the variables, I now have the program working in general.
The channel mapping gave me some nightmares, though. I finally
decided that you need two maps -- one for the channe
band_width / 2,
noaa_chan_width, firdes.WIN_HAMMING, 6.76)
On Sat, Aug 1, 2015 at 5:00 PM, John Ackermann N8UR wrote:
Thanks much for this, Chris! I look forward to playing with it, but...
When I load the flowgraph on my GRC 3.7.6.1 system, I get a "Missing Block"
error for each of l
Thanks much for this, Chris! I look forward to playing with it, but...
When I load the flowgraph on my GRC 3.7.6.1 system, I get a "Missing
Block" error for each of lpf_taps and pbf_taps, triggering errors in the
xfft and channelizer blocks.
I also had an error in the "Multiply Const" block
> This is on the developers radar, I know because I've had discussions about it
> with them in the past. They need more Gui programming help however.
>
> Sent from my iPhone
>
>> On May 18, 2015, at 11:16 AM, John Ackermann N8UR wrote:
>>
>> Hi Marcus
id
in which you can place the GUI elements, and specify how many rows and
columns the individual elements span [1]?
Best regards,
Marcus
[1]
http://gnuradio.org/redmine/projects/gnuradio/wiki/GNURadioCompanion#Example
On 05/18/2015 07:40 PM, John Ackermann N8UR wrote:
I have a flowgraph that inclu
I have a flowgraph that includes a couple of sliders and a frequency
display below.
On a fairly low-res screen (1280x1024), I'm seeing that the flowchart
GUI is fitting itself to the size of the screen, but the individual
components don't all fit without a vertical scroll bar.
I'd like to el
or SDR systems being demo'd at our Hamvention booth (the convention center is
pretty much a Faraday cage). Tests suggest it's going to work really well.
John
> On May 4, 2015, at 9:30 AM, Tom Rondeau wrote:
>
>> On Wed, Apr 29, 2015 at 10:18 AM, John Ackermann N
I'm trying to put gnuradio on a fresh installation of Linux Mint 17.1,
64 bit. The build-gnuradio script was downloaded from SBRAC last night.
I get throught the prerequisites and git fetch OK, but when the
"Building UHD..." step begins, it immediately exits with "UHD build
apparently failed.
Why not make the ratio 1:3 and then you could call it Morse PWM. :-)
On 4/2/2015 2:16 PM, Michael Ossmann wrote:
A friend recently showed me an OOK modulation that I had never seen
before, and I'm wondering if anyone knows a name for this scheme.
It is PWM where both the on periods and off peri
On 5/28/2013 1:28 PM, Simon IJskes wrote:
On 17-05-13 02:22, Marcus D. Leech wrote:
Again, given the fact that your display geometry is likely less than
1280 wide, you'll simply lose information for FFTs larger than that.
I one is looking for weak CW signals, in a waterfall, wouldn't a wide
b
On 9/12/2012 12:15 PM, Michael Ossmann wrote:
On Tue, Sep 11, 2012 at 09:43:42PM -0400, John Ackermann N8UR wrote:
Does anyone know of an image for a bootable Ubuntu or other Linux
distro CD with the GRC stuff installed that's available for download?
The new Pentoo iso includes a GNU
On 9/12/2012 1:02 PM, Rafael Diniz wrote:
Debian wheezy also has gnuradio packages in it's repository.
Best,
Rafael Diniz
Thanks, but I was really looking for a bootable CD image with the
packages already installed so you can run GRC right from the CD. The
idea is to let people follow along
On 9/12/2012 2:28 AM, Alexandru Csete wrote:
[ snip ]
Hi John,
If you have a fresh debian/ubuntu install with GNU Radio & dependencies,
you can use Remasteresys to create a bootable and redistributable copy
of the installation: http://www.remastersys.com/
Not sure if it can be on a CD though.
We're going to be doing a Gnuradio tutorial in conjunction with a ham radio
conference next week and I'd like to hand out a bootable Gnuradio Companion CD
so the attendees can follow along on their laptop.
I know Ettus has the USB drive environment, but we can't afford to hand out
thumb drives
A nearby lightning strike (but far from a direct hit) took out the LNA
on my WBX last fall. I suspect that part of the reason was that the
antenna I was using (a discone wide-band antenna mounted on the roof) is
not DC grounded and thus can develop a good sized charge.
An anecdote: many years
you) and
float everything to somewhere around 60V
-Original Message-
From: discuss-gnuradio-bounces+evan=syndetix@gnu.org
[mailto:discuss-gnuradio-bounces+evan=syndetix@gnu.org] On Behalf Of
John Ackermann N8UR
Sent: Tuesday, February 21, 2012 1:45 PM
To: George Nychis
Cc: d
On 2/21/2012 3:00 PM, George Nychis wrote:
Okay! So apparently there is some interest in power line communication
for GSoC. But, what we would want to do is already have a safe way of
connecting the USRP in to the wall socket for the student(s), and for
the future of GNU Radio and USRP power li
On Oct 14, 2011, at 1:51 PM, "Marcus D. Leech" wrote:
>>
>>
>> Also, looking at your flow-graph, all of the channels are effectively at
>> baseband, so if you have two or more channels come up at the same
> time, they'll collide--was that the intent?
No, I was afraid that might be the case
Marcus D. Leech said the following on 10/14/2011 01:18 PM:
On 14/10/2011 12:53 PM, John Ackermann N8UR wrote:
Doesn't the PFB channelizer down-sample as well? So your output sample
rates from the channelizer will be mis-matched to the
UHD USRP sink?
That's what I'm trying to
Marcus D. Leech said the following on 10/14/2011 12:32 PM:
I have to wonder, though, John, whether your "scheme" for saving power
in a linear transponder is actually going to be workable.
Yes, you'll squelch the "no signal" channels going into the transponder,
but that is only the difference be
Tom Rondeau said the following on 10/14/2011 12:01 PM:
John,
You've almost got it right except for the taps. The "taps" parameter is
the FIR taps of the prototype filter, which then gets partitioned among
the N channels of the channelizer.
While there is no example in GRC readily available, you
Is there a (hopefully simple) example of using the polyphase channelizer
block in grc?
I'm trying to do a simple case of dividing a 250 kHz wide stream from
USRP into a small number (initially 4) of contiguous channels. Given my
generally ignorant status, I'm stumped on setting the parameters
Tom Rondeau said the following on 09/06/2011 11:28 AM:
On Tue, Sep 6, 2011 at 10:22 AM, John Ackermann N8UR mailto:j...@febo.com>> wrote:
I want to implement the equivalent of a carrier-operated relay -- a
squelch block that provides an "on" signal at a threshold
I want to implement the equivalent of a carrier-operated relay -- a
squelch block that provides an "on" signal at a threshold input signal
level, which then passes or blocks data at some point further downstream
rather than right at the point where the sensing is happening.
Are there GRC block
On 09/05/2011 01:10 PM, Marcus D. Leech wrote:
On 05/09/11 12:55 PM, John Ackermann N8UR wrote:
Hi Marcus --
I am selecting complex taps from the drop down, but still get an error at
runtime if either cutoff frequency is 0 or smaller.
Thanks,
John
I just tried it, and it works just
Hi Marcus --
I am selecting complex taps from the drop down, but still get an error at
runtime if either cutoff frequency is 0 or smaller.
Thanks,
John
On Sep 5, 2011, at 11:46 AM, "Marcus D. Leech" wrote:
> On 05/09/11 10:19 AM, John Ackermann N8UR wrote:
>> I&#x
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