# IQ modulation (problem with random source)

**URL:** <https://www.ruby-forum.com/t/iq-modulation-problem-with-random-source/261738>\
**Category:** GNU Radio\
**Created:** [August 19, 2021, 4:36pm UTC](https://www.ruby-forum.com/t/iq-modulation-problem-with-random-source/261738 "2021-08-19T16:36:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![louloulou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d26b3c/32.png) [@louloulou](https://www.ruby-forum.com/u/louloulou)\
**Post date:** [August 19, 2021, 4:36pm UTC](https://www.ruby-forum.com/t/iq-modulation-problem-with-random-source/261738/1 "2021-08-19T16:36:58Z")

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Hello,

I try to study IQ modulation, so I try to simulate this modulation under gnuradio but I have some issues using the Random source to generate my binary data. I try to control the data rate coming from a random source but I don’t understand how to do that. here is a print screen of what I have.

Thank you,

 ![Screenshot from 2021-08-19 12-28-27](https://www.ruby-forum.com/uploads/default/original/2X/8/87efb60765f66a579d4ab85350cc9b2efd66a696.png)

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<div class="post-metadata">

**Author:** ![louloulou](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/d26b3c/32.png) [@louloulou](https://www.ruby-forum.com/u/louloulou)\
**Post date:** [August 19, 2021, 6:09pm UTC](https://www.ruby-forum.com/t/iq-modulation-problem-with-random-source/261738/2 "2021-08-19T18:09:29Z")

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I used the block “Repeat” to slow down the generation of the bit. Here is how I solve the problem.

 ![Screenshot from 2021-08-19 14-08-00](https://www.ruby-forum.com/uploads/default/original/2X/1/1e955b793572fdc45856a29394555f4f64cc384a.png)