# Phase Locking of 2 sine sources **URL:** \ **Category:** GNU Radio\ **Created:** [October 26, 2010, 12:29pm UTC](https://www.ruby-forum.com/t/phase-locking-of-2-sine-sources/198097 "2010-10-26T12:29:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![okkezSS](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/o/85f322/32.png) [@okkezSS](https://www.ruby-forum.com/u/okkezSS)\ **Post date:** [October 26, 2010, 12:29pm UTC](https://www.ruby-forum.com/t/phase-locking-of-2-sine-sources/198097/1 "2010-10-26T12:29:39Z")
Hi, I was wondering how to lock 2 sinewaves in phase with grc. The purpose is to build a descent mpx stereo decoder which locks a local 19khz sine to a bandpassed pilot of a mpx signal, which should improve the audioquality. Thanks in advance… ---
**Author:** ![jjkooij](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ecd19e/32.png) [@jjkooij](https://www.ruby-forum.com/u/jjkooij)\ **Post date:** [October 26, 2010, 10:21pm UTC](https://www.ruby-forum.com/t/phase-locking-of-2-sine-sources/198097/2 "2010-10-26T22:21:01Z")
Use a signal source to generate one, and connect this to a skiphead block to generate the other. The skiphead will cause a set amount on samples to be thrown out initially. That should give you two sinusoids with a constant phase difference. josh ---
**Author:** ![jjkooij](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ecd19e/32.png) [@jjkooij](https://www.ruby-forum.com/u/jjkooij)\ **Post date:** [October 27, 2010, 4:43pm UTC](https://www.ruby-forum.com/t/phase-locking-of-2-sine-sources/198097/3 "2010-10-27T16:43:35Z")
-----Oorspronkelijk bericht----- Van: [discuss-gnuradio-bounces+jasperkanbier=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+jasperkanbier=removed_email_address@domain.invalid) [[mailto:discuss-gnuradio-bounces+jasperkanbier=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+jasperkanbier=removed_email_address@domain.invalid)] Namens Josh B. Verzonden: dinsdag 26 oktober 2010 19:32 Aan: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Onderwerp: Re: [Discuss-gnuradio] Phase Locking of 2 sine sources.. Use a signal source to generate one, and connect this to a skiphead block to generate the other. The skiphead will cause a set amount on samples to be thrown out initially. That should give you two sinusoids with a constant phase difference. josh On 10/26/2010 03:17 AM, Jasper K. wrote: > [Discuss-gnuradio Info Page](http://lists.gnu.org/mailman/listinfo/discuss-gnuradio) * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > **[Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)** ---
**Author:** ![jjkooij](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/ecd19e/32.png) [@jjkooij](https://www.ruby-forum.com/u/jjkooij)\ **Post date:** [October 27, 2010, 5:50pm UTC](https://www.ruby-forum.com/t/phase-locking-of-2-sine-sources/198097/4 "2010-10-27T17:50:13Z")
I guess this works with a “Known” source, but in this case the source signal varies in phase per transmitting station, and there is a need of a pll like circuit who catches the signal and locks this to the local generated sine.. The mpx singal is fed through a bandpass filter with a low cutoff of 18.5khz and a high cutoff of 19.5khz, the remaining pilot sine then needs to be phase compared to a local 19khz source and locked.. I hope someone has a idea.. -----Oorspronkelijk bericht----- Van: [discuss-gnuradio-bounces+jasperkanbier=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+jasperkanbier=removed_email_address@domain.invalid) [[mailto:discuss-gnuradio-bounces+jasperkanbier=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+jasperkanbier=removed_email_address@domain.invalid)] Namens Josh B. Verzonden: dinsdag 26 oktober 2010 19:32 Aan: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Onderwerp: Re: [Discuss-gnuradio] Phase Locking of 2 sine sources.. Use a signal source to generate one, and connect this to a skiphead block to generate the other. The skiphead will cause a set amount on samples to be thrown out initially. That should give you two sinusoids with a constant phase difference. josh On 10/26/2010 03:17 AM, Jasper K. wrote: > [Discuss-gnuradio Info Page](http://lists.gnu.org/mailman/listinfo/discuss-gnuradio) * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > **[Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)**