# GNU Radio **URL:** https://www.ruby-forum.com/c/gnu-radio/15.md?page=9 [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:** 10 --- ## [RTL SDR and GRC3.7.8 problem: format error](https://www.ruby-forum.com/t/rtl-sdr-and-grc3-7-8-problem-format-error/243135)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 25, 2015, 2:28am UTC](https://www.ruby-forum.com/t/rtl-sdr-and-grc3-7-8-problem-format-error/243135 "2015-08-25T02:28:00Z")
Thanks Marcus yet again. In the past gr-osmosdr simply built seamlessly along with gnuradio. Not this time. Don’t know why. My solution was to delete the gr-osmosdr files from the home directory and git clone from … --- ## [VOLK Release v1.1](https://www.ruby-forum.com/t/volk-release-v1-1/243129)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 24, 2015, 8:43pm UTC](https://www.ruby-forum.com/t/volk-release-v1-1/243129 "2015-08-24T20:43:53Z")
Greetings, have a VOLK! Release v1.1 is now available through github and tarballs via the website. Release notes are available in the usual places (website, this email, and git tag description) Contributors The fo… --- ## [RTL SDR and GRC3.7.8 problem: format error](https://www.ruby-forum.com/t/rtl-sdr-and-grc3-7-8-problem-format-error/243128)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 24, 2015, 8:34pm UTC](https://www.ruby-forum.com/t/rtl-sdr-and-grc3-7-8-problem-format-error/243128 "2015-08-24T20:34:32Z")
Ever since I updated to GRC3.7.8 none of my RTL SDR demos will run in GRC. The error messages are the same: " list contains an invalid format". Attached is the .grc file of a basic RTL Qt test flow graph authored usi… --- ## [Ofdm mod error](https://www.ruby-forum.com/t/ofdm-mod-error/243047)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 7\ **Last updated:** [August 24, 2015, 6:33pm UTC](https://www.ruby-forum.com/t/ofdm-mod-error/243047 "2015-08-24T18:33:35Z")
Hi! I’m using gnuradio on ZedBoard and was trying a simple OFDM Mod system just like in this video the flowgraph just looks like this… random source\>short to float\>ofdm mod\>throttle\>wx gui fft sink and t… --- ## [OOT Module Attribute Error module object has no attribute 'blockname'](https://www.ruby-forum.com/t/oot-module-attribute-error-module-object-has-no-attribute-blockname/243071)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 9\ **Last updated:** [August 24, 2015, 6:31pm UTC](https://www.ruby-forum.com/t/oot-module-attribute-error-module-object-has-no-attribute-blockname/243071 "2015-08-24T18:31:50Z")
Hello all, I know this question has been asked before, several times, but I didn’t find a solution that allowed me to use my OOT blocks without running into the error stated in the subject of this email. I scoured t… --- ## [Add multiple gated streams](https://www.ruby-forum.com/t/add-multiple-gated-streams/243119)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 23, 2015, 10:28pm UTC](https://www.ruby-forum.com/t/add-multiple-gated-streams/243119 "2015-08-23T22:28:20Z")
Anyone have an idea how I can sum (add\_ff) multiple, gated streams into a single stream? For example, the gr-dsd block gates it’s output when there is nothing to decode. I can sum multiple decoders together for a si… --- ## [DECT voice channel decoding project](https://www.ruby-forum.com/t/dect-voice-channel-decoding-project/243075)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 3\ **Last updated:** [August 23, 2015, 8:32pm UTC](https://www.ruby-forum.com/t/dect-voice-channel-decoding-project/243075 "2015-08-23T20:32:04Z")
Dear all, I was working on a project of real-time DECT voice channel decoding. I believe it might be useful for the community. So I have decided to share it. It is available on github with short installation and usag… --- ## [Communication problems between 2 USRP's](https://www.ruby-forum.com/t/communication-problems-between-2-usrps/242820)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 8\ **Last updated:** [August 23, 2015, 1:43am UTC](https://www.ruby-forum.com/t/communication-problems-between-2-usrps/242820 "2015-08-23T01:43:28Z")
Hi all, I want to transmit the data between two USRP’s and make them communicate with each other. But I guess the packets are not being received properly… My USRP daughterboard model is XCVR2450. When I am running .… --- ## [GPS Signals recorded IQ samples file](https://www.ruby-forum.com/t/gps-signals-recorded-iq-samples-file/243100)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 7\ **Last updated:** [August 22, 2015, 5:35pm UTC](https://www.ruby-forum.com/t/gps-signals-recorded-iq-samples-file/243100 "2015-08-22T17:35:07Z")
Hi! After googling a lot and searching in this lists archive, I couldn’t find any recording of IQ samples from GPS signals. I’m trying to record one myself, with no luck so far because (I suspect) of a malfunctioni… --- ## [Channel setting for USRP](https://www.ruby-forum.com/t/channel-setting-for-usrp/242972)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 22, 2015, 2:47pm UTC](https://www.ruby-forum.com/t/channel-setting-for-usrp/242972 "2015-08-22T14:47:28Z")
Hi all, I want to transmit the data between two USRP’s and make them communicate with each other. But I guess the packets are not being received properly. My USRP daughterboard model is XCVR2450. When I am running .… --- ## [Install UHD on Windows 10 problem](https://www.ruby-forum.com/t/install-uhd-on-windows-10-problem/243106)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 21, 2015, 11:06pm UTC](https://www.ruby-forum.com/t/install-uhd-on-windows-10-problem/243106 "2015-08-21T23:06:57Z")
Hi, I have been trying to install the latest version of UHD onWindows 10. I successfully installed , I think, uhd\_003.008.005-release\_Win64\_VS2013.exe. The HTML manual provides detailed instructions to install the US… --- ## [Help with building GNU Radio for Android](https://www.ruby-forum.com/t/help-with-building-gnu-radio-for-android/243053)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 4\ **Last updated:** [August 21, 2015, 9:42pm UTC](https://www.ruby-forum.com/t/help-with-building-gnu-radio-for-android/243053 "2015-08-21T21:42:50Z")
I am trying to build GNU Radio for Android and am having issues with the build process. I first tried building GNU Radio for Android on Mac OS X 10.10.4. I was able to follow the directions successfully until I had to… --- ## [Follow up: Failure to build GNU Radio on various Ubuntu builds](https://www.ruby-forum.com/t/follow-up-failure-to-build-gnu-radio-on-various-ubuntu-builds/243057)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 6\ **Last updated:** [August 21, 2015, 7:44pm UTC](https://www.ruby-forum.com/t/follow-up-failure-to-build-gnu-radio-on-various-ubuntu-builds/243057 "2015-08-21T19:44:49Z")
I managed to resolve a problem with the install. Commands, find\_usrp\_devices and uhd\_usrp\_probe failed to get my B100 to respond with the model and daughter board and FPGA information. Yet at other times it would wor… --- ## [Enveloping a transmit amplifier](https://www.ruby-forum.com/t/enveloping-a-transmit-amplifier/243058)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 4\ **Last updated:** [August 21, 2015, 3:02pm UTC](https://www.ruby-forum.com/t/enveloping-a-transmit-amplifier/243058 "2015-08-21T15:02:04Z")
Hello, I’m transmitting a fairly bursty, irregularly timed signal. I attach a stream tag to the sample that has the start of the burst (tx\_sob). I also have a PA that I can turn on and off that’s inbetween my USRP … --- ## [Filters in GNU Radio](https://www.ruby-forum.com/t/filters-in-gnu-radio/243096)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 21, 2015, 2:13pm UTC](https://www.ruby-forum.com/t/filters-in-gnu-radio/243096 "2015-08-21T14:13:00Z")
Am I correct in concluding when I use fir\_filter\_fff to filter, that because it uses its own memory space, I don’t need to use set\_history and worry about boundary crossing between calls to work? Will the output of t… --- ## [DRM receiver](https://www.ruby-forum.com/t/drm-receiver/243086)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 5\ **Last updated:** [August 21, 2015, 10:24am UTC](https://www.ruby-forum.com/t/drm-receiver/243086 "2015-08-21T10:24:00Z")
Dear List! Does anyone have any experience with using GNURADIO as DRM receiver? Or using Dream as a library to gnuradio? Any help will be nice (= Best regards Havard Austad --- ## [Tenth Special Cyberspectrum SDR Meetup next week in Washington, DC! (Wed 26th June)](https://www.ruby-forum.com/t/tenth-special-cyberspectrum-sdr-meetup-next-week-in-washington-dc-wed-26th-june/243098)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 21, 2015, 5:31am UTC](https://www.ruby-forum.com/t/tenth-special-cyberspectrum-sdr-meetup-next-week-in-washington-dc-wed-26th-june/243098 "2015-08-21T05:31:19Z")
Hi all, We’re pleased to announce the Tenth Special Cyberspectrum meetup, which will be held in Washington, DC, during the week of the 2015 GNU Radio conference: Login to Meetup | Meetup Please RSVP if you’re coming … --- ## [GRCon15 next week!](https://www.ruby-forum.com/t/grcon15-next-week/243099)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 21, 2015, 3:39am UTC](https://www.ruby-forum.com/t/grcon15-next-week/243099 "2015-08-21T03:39:06Z")
Hey everyone, I wanted to send a final note about GRCon15 coming up in DC next week. We have an incredibly lineup of speakers throughout the week and an audience to match. We still have space available this year as … --- ## [Channel sounding in GNU Radio](https://www.ruby-forum.com/t/channel-sounding-in-gnu-radio/243097)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 21, 2015, 3:18am UTC](https://www.ruby-forum.com/t/channel-sounding-in-gnu-radio/243097 "2015-08-21T03:18:04Z")
Hello, I’m sending a specific frame (length 400 bits), and I would like to examine the received signal through the channel (delay profile, coherence time, …). At the receiver, I have In Phase and Quadrature part. Is … --- ## [Implementing a FIR Filter](https://www.ruby-forum.com/t/implementing-a-fir-filter/243059)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 7\ **Last updated:** [August 21, 2015, 2:03am UTC](https://www.ruby-forum.com/t/implementing-a-fir-filter/243059 "2015-08-21T02:03:16Z")
Hi all, Would someone please recommend a good starting point in C++ source code that demonstrates how one uses the kernel::fir\_filter. I started following the pfb\_clock\_sync method of implementing it, but then realiz… --- ## [Bug in block::declare\_sample\_delay](https://www.ruby-forum.com/t/bug-in-block-declare-sample-delay/243095)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 0\ **Last updated:** [August 21, 2015, 12:48am UTC](https://www.ruby-forum.com/t/bug-in-block-declare-sample-delay/243095 "2015-08-21T00:48:29Z")
Hello, I think that the declare\_sample\_delay (and/or the way it is used) is implemented incorrectly for interpolator blocks. Using GR 3.7.6. The delay should be added after scaling the offset by the interpolation ra… --- ## [SEGFAULT when using GR\_LOG\_INFO](https://www.ruby-forum.com/t/segfault-when-using-gr-log-info/243026)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 1\ **Last updated:** [August 20, 2015, 11:10am UTC](https://www.ruby-forum.com/t/segfault-when-using-gr-log-info/243026 "2015-08-20T11:10:22Z")
Hi everyone, I want to use logging in GNURadio. I followed this link to use the logger : https://gnuradio.org/doc/doxygen/page\_logger.html. I modified my CMakiefile.txt to link LOG4CPP dirs & libs. I added the FindL… --- ## [Dealing with \`divide 0\` or \`Inf\` in GNU Radio C++ code](https://www.ruby-forum.com/t/dealing-with-divide-0-or-inf-in-gnu-radio-c-code/243067)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 3\ **Last updated:** [August 20, 2015, 9:32am UTC](https://www.ruby-forum.com/t/dealing-with-divide-0-or-inf-in-gnu-radio-c-code/243067 "2015-08-20T09:32:28Z")
Let’s think about the following auto/cross correlator: http://i.imgur.com/Fy5hdVj.png I’ve placed divide because I need to normalize the correlation result. If we place null source, or constant source with value of ze… --- ## [New OOT block shows up in list but erases flowgraph when i use it](https://www.ruby-forum.com/t/new-oot-block-shows-up-in-list-but-erases-flowgraph-when-i-use-it/243069)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 19, 2015, 7:05pm UTC](https://www.ruby-forum.com/t/new-oot-block-shows-up-in-list-but-erases-flowgraph-when-i-use-it/243069 "2015-08-19T19:05:31Z")
I wrote an out of tree block based on the tutorial and after i compile it, the block shows up in the list in GRC, but when i drag it into the flowgraph it erases the whole thing options block and all. as a workaround… --- ## [Error when running GRC flowchart in No GUI mode](https://www.ruby-forum.com/t/error-when-running-grc-flowchart-in-no-gui-mode/243064)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 19, 2015, 12:39pm UTC](https://www.ruby-forum.com/t/error-when-running-grc-flowchart-in-no-gui-mode/243064 "2015-08-19T12:39:22Z")
Hi all, I’m having trouble when trying to run a GRC flowchart with the No GUI option. The thing is that even with the simplest flowchart I get the following error: can only concatenate list (not “str”) to list. I’ve … --- ## [RX/TX transceiver](https://www.ruby-forum.com/t/rx-tx-transceiver/243049)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 1\ **Last updated:** [August 18, 2015, 4:17pm UTC](https://www.ruby-forum.com/t/rx-tx-transceiver/243049 "2015-08-18T16:17:16Z")
Hi All, I have some issues when using UHD sink and source blocks in same flow graph. When I transmit data with UHD sink, I use tx\_sob and tx\_eob. I don’t get any underflow error. But, the problem is that I can see a… --- ## [Help with building GNU Radio for Android](https://www.ruby-forum.com/t/help-with-building-gnu-radio-for-android/243052)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 0\ **Last updated:** [August 18, 2015, 2:58pm UTC](https://www.ruby-forum.com/t/help-with-building-gnu-radio-for-android/243052 "2015-08-18T14:58:59Z")
I am trying to build GNU Radio for Android and am having issues with the build process. I first tried building GNU Radio for Android on Mac OS X 10.10.4. I was able to follow the directions successfully until I had to… --- ## [SDR/USRP devices](https://www.ruby-forum.com/t/sdr-usrp-devices/243041)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 5\ **Last updated:** [August 18, 2015, 2:08pm UTC](https://www.ruby-forum.com/t/sdr-usrp-devices/243041 "2015-08-18T14:08:09Z")
Hello, I’ve been searching a lot about SDR and USRP devices to purchase. All I need is a board with a receiver port (transmitter is not important for now) and it’s necessary to be compatible with Gnuradio. There are … --- ## [Experience with Ubuntu 15.04 and Gnuradio 3.7.8](https://www.ruby-forum.com/t/experience-with-ubuntu-15-04-and-gnuradio-3-7-8/243043)
**Author:** [@Sadaf\_N](https://www.ruby-forum.com/u/Sadaf_N)\ **Replies:** 2\ **Last updated:** [August 18, 2015, 1:38am UTC](https://www.ruby-forum.com/t/experience-with-ubuntu-15-04-and-gnuradio-3-7-8/243043 "2015-08-18T01:38:41Z")
All, I am considering updating to Ubuntu 15.04 from 14.04 and want to continue with GRC 3.7.8. Anyone with experience using new Ubuntu release and Gnuradio? Regards, John Petrich --- ## [Gradual loss of amplitude as flowgraph runs](https://www.ruby-forum.com/t/gradual-loss-of-amplitude-as-flowgraph-runs/243015)
**Author:** [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Replies:** 2\ **Last updated:** [August 18, 2015, 12:51am UTC](https://www.ruby-forum.com/t/gradual-loss-of-amplitude-as-flowgraph-runs/243015 "2015-08-18T00:51:57Z")
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 … [Previous page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=8) [Next page](https://www.ruby-forum.com/c/gnu-radio/15.md?page=10)