# Data type in the output of the source

**URL:** <https://www.ruby-forum.com/t/data-type-in-the-output-of-the-source/231622>\
**Category:** GNU Radio\
**Created:** [August 19, 2014, 9:52pm UTC](https://www.ruby-forum.com/t/data-type-in-the-output-of-the-source/231622 "2014-08-19T21:52:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [August 19, 2014, 9:52pm UTC](https://www.ruby-forum.com/t/data-type-in-the-output-of-the-source/231622/1 "2014-08-19T21:52:33Z")

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Hi Guys,

I have a new question about the type of the data in the output of the  
source (RTL2832). The signal is represented with complex numbers! why?  
What  
do this complex numbers means physically?

In my head the data in the output should be real, should it?

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**Author:** ![Rodrigo\_RozSSrio](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e19b73/32.png) [@Rodrigo\_RozSSrio](https://www.ruby-forum.com/u/Rodrigo_RozSSrio)\
**Post date:** [August 19, 2014, 9:58pm UTC](https://www.ruby-forum.com/t/data-type-in-the-output-of-the-source/231622/2 "2014-08-19T21:58:02Z")

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On 08/19/2014 03:51 PM, Rodrigo Rozrio wrote:

> /CREA-DF - 21339/D-DF/  
> /Engenheiro de Redes de Comunicao /  
> /Universidade de Braslia/
> 
> * * *
> 
> 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)  
> The RTL delivers complex-baseband data. NOT a real-valued IF.

This is ery common in the SDR space, even if the analog bits are using a  
real-valued IF, the post-digitization typically delivers a complex  
(zero-based)  
baseband.