# GNU Radio **URL:** https://www.ruby-forum.com/c/gnu-radio/15.md?page=10 [Latest](https://www.ruby-forum.com/latest.md) · [Categories](https://www.ruby-forum.com/categories.md) · [Tags](https://www.ruby-forum.com/tags.md) **Page:** 11 --- ## [Problem with QPSK receiver](https://www.ruby-forum.com/t/problem-with-qpsk-receiver/243045)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 17, 2015, 11:48pm UTC](https://www.ruby-forum.com/t/problem-with-qpsk-receiver/243045 "2015-08-17T23:48:10Z")
Hi all, First time posting here, so hello everyone:) I am trying to build this pair of GNUradio flow graph for QPSK signal transmitting and receiving over the air through USRP. Now the transmitter side is straight fo… --- ## [How to change PSK roll-off during runtime (or an arbitrary parameter)](https://www.ruby-forum.com/t/how-to-change-psk-roll-off-during-runtime-or-an-arbitrary-parameter/243042)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 17, 2015, 8:07pm UTC](https://www.ruby-forum.com/t/how-to-change-psk-roll-off-during-runtime-or-an-arbitrary-parameter/243042 "2015-08-17T20:07:27Z")
Hi all! Thank you for contributing to gnuradio and providing new users like me with help. I have read and worked through some of the guided tutorials. However I come to a point now where it seems that own Python code… --- ## [R820t2/rtl2838u](https://www.ruby-forum.com/t/r820t2-rtl2838u/242990)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 17, 2015, 7:37pm UTC](https://www.ruby-forum.com/t/r820t2-rtl2838u/242990 "2015-08-17T19:37:32Z")
Hello, guys. Please, does someone know if these two RTL devices (R820T2 and RTL2838U) work fine with Gnuradio? Which is better? Thanks a lot. Cheers, Antony --- ## [Re: hier\_blocks2 error](https://www.ruby-forum.com/t/re-hier-blocks2-error/243038)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 17, 2015, 12:19pm UTC](https://www.ruby-forum.com/t/re-hier-blocks2-error/243038 "2015-08-17T12:19:30Z")
AttributeError: ‘hier\_block2\_sptr’ object has no attribute ‘\_hb’ marked protected they should not be accessed from outside the wrapper directly (I remember some WXGUI code did that, but that has been fixed). In the … --- ## [HAM2MON update](https://www.ruby-forum.com/t/ham2mon-update/243034)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 17, 2015, 4:11am UTC](https://www.ruby-forum.com/t/ham2mon-update/243034 "2015-08-17T04:11:44Z")
Added AM demodulation for VHF air-band reception, via “-d 0” option switch for NBFM (default) and “-d 1“ for AM. OP25 via gr-dsd next on agenda; maybe at hackfest. Lou – View this message in context: http://gn… --- ## [Cyclostationary analysis - Find baudrate](https://www.ruby-forum.com/t/cyclostationary-analysis-find-baudrate/243030)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 16, 2015, 9:51pm UTC](https://www.ruby-forum.com/t/cyclostationary-analysis-find-baudrate/243030 "2015-08-16T21:51:21Z")
Hi All, I am trying to do perform cyclostationary analysis to determine the periodicity of the signal to find the symbol or baud rate of the raw modulated data. I am trying to use GRC setup described in gr-baz. ( Fil… --- ## [Spending the whole day to build gnuradio on a Mac?](https://www.ruby-forum.com/t/spending-the-whole-day-to-build-gnuradio-on-a-mac/243019)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 16, 2015, 3:40am UTC](https://www.ruby-forum.com/t/spending-the-whole-day-to-build-gnuradio-on-a-mac/243019 "2015-08-16T03:40:48Z")
Mac OSX 10.10.4 gnuradio 3.7.7.1 homebrew Trying to get the SDPplay to work using gr-osmosdr I tried an innocent brew install gnuradio. That went wrong on the fact that gnuradio was compiled against the homebrew pyt… --- ## [USRP1 warning "requested RX frequency is outside of the system range, requested RX frequency is outs](https://www.ruby-forum.com/t/usrp1-warning-requested-rx-frequency-is-outside-of-the-system-range-requested-rx-frequency-is-outs/243004)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 3\ **Last updated:** [August 16, 2015, 1:19am UTC](https://www.ruby-forum.com/t/usrp1-warning-requested-rx-frequency-is-outside-of-the-system-range-requested-rx-frequency-is-outs/243004 "2015-08-16T01:19:26Z")
Dear, Sorry if I have too much question, I am getting started with GNU radio, and I did not find the answer for this on the Internet. I have USRP1 and inside it has 2 daughter boards: WBX and RFX400. I run the FM re… --- ## [Runtime error - Empty Device Address in GRC Flowgraph build](https://www.ruby-forum.com/t/runtime-error-empty-device-address-in-grc-flowgraph-build/243020)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 15, 2015, 7:31pm UTC](https://www.ruby-forum.com/t/runtime-error-empty-device-address-in-grc-flowgraph-build/243020 "2015-08-15T19:31:16Z")
Hello, After installing GRC into Ubuntu 15.05 64bit I get the following error when trying to run a GRC flow graph example:- RuntimeError: LookupError: KeyError: No devices found for -----\> Empty Device Address A u… --- ## [Tutorial 2.4.5 The Singing Sine Wave](https://www.ruby-forum.com/t/tutorial-2-4-5-the-singing-sine-wave/243016)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 15, 2015, 1:57pm UTC](https://www.ruby-forum.com/t/tutorial-2-4-5-the-singing-sine-wave/243016 "2015-08-15T13:57:09Z")
Hi, I have two questions to the above mentioned Tutorial chapter, since I realized two differences, even though I think I set it up the same. a) To get an acceptable view in the Waterfall graph I had to adjust the fr… --- ## [Looking for photos of embedded systems running GNU Radio](https://www.ruby-forum.com/t/looking-for-photos-of-embedded-systems-running-gnu-radio/243017)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 15, 2015, 9:51am UTC](https://www.ruby-forum.com/t/looking-for-photos-of-embedded-systems-running-gnu-radio/243017 "2015-08-15T09:51:48Z")
I’d like to get some photos of Embedded systems running GNU Radio for the Embedded WG poster at GR Con. These can be as simple as a dev board and a USRP or other digitizer to interesting systems. Philip --- ## [OMP Data. GNURadio overhead?](https://www.ruby-forum.com/t/omp-data-gnuradio-overhead/243012)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 15, 2015, 6:22am UTC](https://www.ruby-forum.com/t/omp-data-gnuradio-overhead/243012 "2015-08-15T06:22:40Z")
Sorry for the HTML… I have been done some work applying OpenMP to GNURadio and collected some data. This data was collected WITHOUT GNURadio overhead. Specifically, I interfaced directly with my detector passing 30 se… --- ## [Gnu radio install problems CMake Error with UHD\_LIBRARIES](https://www.ruby-forum.com/t/gnu-radio-install-problems-cmake-error-with-uhd-libraries/243018)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 15, 2015, 12:50am UTC](https://www.ruby-forum.com/t/gnu-radio-install-problems-cmake-error-with-uhd-libraries/243018 "2015-08-15T00:50:52Z")
Hi I’m trying to install gnuradio and I have used the following command to retrieve the source code (after yum install gnuradio resulted in “no package gnuradio available”): git clone --recursive git:// git.gnuradio.… --- ## [SDRplay and gnuradio](https://www.ruby-forum.com/t/sdrplay-and-gnuradio/243014)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 14, 2015, 9:21pm UTC](https://www.ruby-forum.com/t/sdrplay-and-gnuradio/243014 "2015-08-14T21:21:42Z")
Hi all! First message here. Still learning to work efficiently with gnuradio. Issue is not the software, issue is the background theory of signal processing that i need to shape up on. Using gnuradio is pretty easy. … --- ## [Energy Detection Sensing Time Calculation?](https://www.ruby-forum.com/t/energy-detection-sensing-time-calculation/243010)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 14, 2015, 7:02pm UTC](https://www.ruby-forum.com/t/energy-detection-sensing-time-calculation/243010 "2015-08-14T19:02:04Z")
Hello community, How do I calculate the sensing time of my Energy Detection flow graph in GRC? Any tips? Thanks. – Best, \*Gerome Jan M. Llames \* Engineering Research and Development for Technology (ERDT) Scholar U… --- ## [Re: bidirectional with Socket PDU](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/243007)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 14, 2015, 4:33pm UTC](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/243007 "2015-08-14T16:33:39Z")
If someone has an alternative, I am all ears (I’m coming up empty). I got it working now. If someone wants to do something similar, what I did was take the python example code from here: (the last section of code … --- ## [SOCIS project update 11](https://www.ruby-forum.com/t/socis-project-update-11/243006)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 14, 2015, 3:21pm UTC](https://www.ruby-forum.com/t/socis-project-update-11/243006 "2015-08-14T15:21:12Z")
\-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hey GNU Radio’ers! SOCIS project deadline is near. So I’m trying to finish all outstanding tasks. Earlier this week I could issue a pull request against VOLK. So my new … --- ## [Failure to build GNU Radio on various Ubuntu builds](https://www.ruby-forum.com/t/failure-to-build-gnu-radio-on-various-ubuntu-builds/243005)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 14, 2015, 3:19pm UTC](https://www.ruby-forum.com/t/failure-to-build-gnu-radio-on-various-ubuntu-builds/243005 "2015-08-14T15:19:27Z")
Hello, After trying to install GNU Radio over the past few days I’vebeen unsuccessful due to various failures of GNU Radio to build. The latest error is as follows:- Segmentation fault (core dumped)gr-blocks/swig/CMak… --- ## [FFT Scaling](https://www.ruby-forum.com/t/fft-scaling/242980)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 3\ **Last updated:** [August 14, 2015, 3:05am UTC](https://www.ruby-forum.com/t/fft-scaling/242980 "2015-08-14T03:05:27Z")
There is an internal scaling effect of fftlen (the length of your FFT) in the FFT block. How do I unscale or remove the scaling factor in the python generated by thr GRC? I tried the one suggested in the faq, … forw… --- ## [Re: bidirectional with Socket PDU](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/242998)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 13, 2015, 11:04pm UTC](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/242998 "2015-08-13T23:04:11Z")
OK, maybe it is an issue with netcat then. I don’t think one netcat instance can both transmit and receive, so when I try to run it twice, that is when it dies. I will have to look for another app that can do somethi… --- ## [Re: bidirectional with Socket PDU](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/242997)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 13, 2015, 9:40pm UTC](https://www.ruby-forum.com/t/re-bidirectional-with-socket-pdu/242997 "2015-08-13T21:40:39Z")
You should be fine connecting both input and output ports at the same time for exactly this purpose! OK, maybe it is an issue with netcat then. I don’t think one netcat instance can both transmit and receive, so whe… --- ## [Bidirectional with Socket PDU](https://www.ruby-forum.com/t/bidirectional-with-socket-pdu/242996)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 13, 2015, 9:37pm UTC](https://www.ruby-forum.com/t/bidirectional-with-socket-pdu/242996 "2015-08-13T21:37:09Z")
This will probably show my networking ignorance, but is there a way to use the socket PDU for bi-directional purposes? I see that it has a PDU in and out, but I cant’ seem to get it to work. What I am doing is connec… --- ## [GQRX raw IQ file format / structure?](https://www.ruby-forum.com/t/gqrx-raw-iq-file-format-structure/242994)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 13, 2015, 9:09pm UTC](https://www.ruby-forum.com/t/gqrx-raw-iq-file-format-structure/242994 "2015-08-13T21:09:41Z")
GQRX has a built-in I/Q recorder (tools menu) to save raw I/Q files. I would like to process these files with Python and other signal processing software. Does anybody know the exact format and structure of these file… --- ## [Error when running GNU radio built from script](https://www.ruby-forum.com/t/error-when-running-gnu-radio-built-from-script/242973)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 3\ **Last updated:** [August 13, 2015, 8:23pm UTC](https://www.ruby-forum.com/t/error-when-running-gnu-radio-built-from-script/242973 "2015-08-13T20:23:32Z")
Dear, I installed GNU radio from build\_gnuradio script successful. Then I tried a simple FM receiver and I got this warning : UHD Warning: Could not locate USRP1 firmware. Please run: “/usr/local/lib/uhd/utils/uhd\_i… --- ## [Writing Messages to a File](https://www.ruby-forum.com/t/writing-messages-to-a-file/242991)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 13, 2015, 7:16pm UTC](https://www.ruby-forum.com/t/writing-messages-to-a-file/242991 "2015-08-13T19:16:21Z")
Does anyone have methods to write messages to a file? My use case is tagging baseband sample numbers of the start/end of WLAN packets in gr-ieee80211. It looks like typically people create custom blocks to deal with … --- ## [Error with running wifi\_loopback.grc from gr-ieee802-11](https://www.ruby-forum.com/t/error-with-running-wifi-loopback-grc-from-gr-ieee802-11/242983)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 9\ **Last updated:** [August 13, 2015, 5:36pm UTC](https://www.ruby-forum.com/t/error-with-running-wifi-loopback-grc-from-gr-ieee802-11/242983 "2015-08-13T17:36:27Z")
Discuss-gnuradio mailing list removed\_email\_address@domain.invalid https://lists.gnu.org/mailman/listinfo/discuss-gnuradio --- ## [Hier\_blocks2 error](https://www.ruby-forum.com/t/hier-blocks2-error/242987)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 13, 2015, 9:18am UTC](https://www.ruby-forum.com/t/hier-blocks2-error/242987 "2015-08-13T09:18:41Z")
I am using gnruadio 3.7.8. I have a module (python) which is working well for version 3.6.3. In made necessary changes so that it can work with gnuradio 3.7.8. However I am getting following error File “/usr/local/l… --- ## [No revision detected MB EEPROM must be reprogrammed!](https://www.ruby-forum.com/t/no-revision-detected-mb-eeprom-must-be-reprogrammed/242963)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 13, 2015, 3:19am UTC](https://www.ruby-forum.com/t/no-revision-detected-mb-eeprom-must-be-reprogrammed/242963 "2015-08-13T03:19:25Z")
\[Note: The reason I’m posting this here is because I’m not sure whether this is solely a UHD problem or perhaps because of some ‘suboptimal’ communication between GNURadio & UHD, and I’ve seen some earlier posts on t… --- ## [Run](https://www.ruby-forum.com/t/run/242982)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 12, 2015, 7:22pm UTC](https://www.ruby-forum.com/t/run/242982 "2015-08-12T19:22:40Z")
Discuss-gnuradio mailing list removed\_email\_address@domain.invalid https://lists.gnu.org/mailman/listinfo/discuss-gnuradio --- ## [Re: mirrored spectrum around tuning freq](https://www.ruby-forum.com/t/re-mirrored-spectrum-around-tuning-freq/242981)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 12, 2015, 6:23pm UTC](https://www.ruby-forum.com/t/re-mirrored-spectrum-around-tuning-freq/242981 "2015-08-12T18:23:04Z")
Hi Marcus, in the picture you see the power output of the signal generator is -30 dBm. Changing it to -90 dBm does not produce any change in the received signal except a (obvious) lower level. There is not other am… [Previous page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=9) [Next page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=11)