# Frequency Counter‏ **URL:** \ **Category:** GNU Radio\ **Created:** [May 5, 2014, 10:27am UTC](https://www.ruby-forum.com/t/frequency-counter/240889 "2014-05-05T10:27:23Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\ **Post date:** [May 5, 2014, 10:27am UTC](https://www.ruby-forum.com/t/frequency-counter/240889/1 "2014-05-05T10:27:23Z")
Hi list, Has anyone been able to implement a frequency counter yet? Any ideas on how I should try it? ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [May 5, 2014, 5:42pm UTC](https://www.ruby-forum.com/t/frequency-counter/240889/2 "2014-05-05T17:42:43Z")
jimsiaf91 wrote > Hi list, Has anyone been able to implement a frequency counter yet? > Any ideas on how I should try it? > > * * * > > Discuss-gnuradio mailing list > Discuss-gnuradio@ > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) I have been pulling FFT vectors out of the flow into python using a message queue, then finding the frequency of the maximum bin. I suppose you could do this, retune the USRP or channelizer, then increase the decimation. Keep doing this to narrow down the spectrum. I suppose a gated type counter would work too, where you just could the cycles, and may work better for modulated signals. Lou KD4HSO – View this message in context: [http://gnuradio.4.n7.nabble.com/Frequency-Counter-tp47952p47957.html](http://gnuradio.4.n7.nabble.com/Frequency-Counter-tp47952p47957.html) Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com). ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [May 5, 2014, 5:56pm UTC](https://www.ruby-forum.com/t/frequency-counter/240889/3 "2014-05-05T17:56:51Z")
The ‘spectrum sense mode’ in scanoo locks on to the strongest signal within the rx bandwidth. Just set the squelch and then enable spectrum sense in the spectrum sense tab: > **[GitHub - m0mik/scanoo: This project no longer works so please try Ham2Mon -\>](https://github.com/m0mik/scanoo)** > > This project no longer works so please try Ham2Mon -\> - GitHub - m0mik/scanoo: This project no longer works so please try Ham2Mon -\> Mike – Mike J. M0MIK BSc MIET Email: removed\_email\_address@domain.invalid Web: [http://scanoo.com](http://scanoo.com) ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [May 6, 2014, 12:54pm UTC](https://www.ruby-forum.com/t/frequency-counter/240889/4 "2014-05-06T12:54:19Z")
Ah sorry, I didn’t mean to put it that way: It’s not an analog device; the thing I wanted to point out that there being a device that counts frequency --to me-- belongs to a very “analog” thinking (i.e. it’s not math on a computer, but an actual thing with an HF connector). Actually, you’re absolutely right, counting things in discrete steps in defined time intervals is the most digital thing one could do. Thanks for your mail! Greetings, Marcus ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [May 5, 2014, 5:58pm UTC](https://www.ruby-forum.com/t/frequency-counter/240889/5 "2014-05-05T17:58:42Z")
Hi Dimitris, a frequency counter counter is a very analog-world concept, I’d say. As DSP person I’d assume you’d want a frequency estimator. You can implement a simple one by using an FFT block, abs, max arg chain, or just get your result from looking at any FFT plot. Anyway, for spectrum estimation, I recommend the gr-specest toolbox, > **[GitHub - kit-cel/gr-specest: A module adding spectral estimation routines to...](https://github.com/kit-cel/gr-specest)** > > A module adding spectral estimation routines to GNU Radio. - GitHub - kit-cel/gr-specest: A module adding spectral estimation routines to GNU Radio. Greetings, Marcus On Mon, May 5, 2014 at 10:25 AM, Dimitris Siafarikas ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [June 3, 2014, 2:06pm UTC](https://www.ruby-forum.com/t/frequency-counter/240889/6 "2014-06-03T14:06:51Z")
On Mon, May 5, 2014 at 4:25 PM, Dimitris Siafarikas [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hi list, > > Has anyone been able to implement a frequency counter yet? > > Any ideas on how I should try it? Hi Dimitris, Yes. I have recently created a block for frequency counting, refer > **[GitHub - activecat/gr-test2: GNU Radio: more examples](https://github.com/activecat/gr-test2)** > > GNU Radio: more examples Try to run this flowgraph: gr-test2/examples/flowgraph\_04.grc amazingly it shows quite an accurate result. Let’s test it with various frequencies by adjusting the GUI Slider. I created this block when I need to observe the frequency stability of signal from USRP, as in flowgraph\_05. Hope this block is useful to you too. ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [June 8, 2014, 2:36am UTC](https://www.ruby-forum.com/t/frequency-counter/240889/7 "2014-06-08T02:36:45Z")
First of all, please stay on the list. Refer inline reply below. On Fri, Jun 6, 2014 at 11:12 PM, jimsiaf91 [via GnuRadio] \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > Well, > I tried it with my usrp N210. The first time it showed something on the > Scope sink. After that it did not. Your setup could be wrong. > Only when I run first the flowgraph\_6.grc then the 5th ( the one with the > USRP source) showed something. I do not understand why this is happening. I see no correlation on this. > Besides that, I tried to measure at 2Ghz with and external frequency > generator (sin) and also attached a number sink after the block you wrote. > The number sink did not show 2Ghz (in units), instead jittered at about > 1000 units. If the Sample Rate (samp\_rate) of the UHD (USRP) source is only 100kHz, it cannot measure 2GHz external frequency. Refer Nyquist sampling theory. ---
**Author:** ![Dimitris\_Siafarikas](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/9fc29f/32.png) [@Dimitris\_Siafarikas](https://www.ruby-forum.com/u/Dimitris_Siafarikas)\ **Post date:** [June 6, 2014, 4:46am UTC](https://www.ruby-forum.com/t/frequency-counter/240889/8 "2014-06-06T04:46:33Z")
On Tue, Jun 3, 2014 at 11:41 PM, Dimitris Siafarikas [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Exceptional work! Looking forward to try this with my usrp tomorrow 😉 Dimitris, How is your test result with USRP, any updates ..?