# Using GRC without UHD

**URL:** <https://www.ruby-forum.com/t/using-grc-without-uhd/240325>\
**Category:** GNU Radio\
**Created:** [April 8, 2014, 5:38pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325 "2014-04-08T17:38:10Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\
**Post date:** [April 8, 2014, 5:38pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/1 "2014-04-08T17:38:10Z")

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Hello GR,

Are there any fake sink and source blocks which simulates the uhd sink  
and  
source.  
I would like to test some flow graphs but for the moment I don’t have  
access  
to the radios.

Or is there any other option, let’s say using a channel block between  
the Tx  
and the Rx.

Any hints or explanation are well appreciated.

Regards,  
Ruecan

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Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com).

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**Author:** ![naeo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@naeo](https://www.ruby-forum.com/u/naeo)\
**Post date:** [April 8, 2014, 5:44pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/2 "2014-04-08T17:44:35Z")

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On 04/08/2014 05:36 PM, Ruecan wrote:

> Any hints or explanation are well appreciated.  
> You can use file sinks- and sources. There’s also several different  
> channel blocks.

Martin

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**Author:** ![naeo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@naeo](https://www.ruby-forum.com/u/naeo)\
**Post date:** [April 8, 2014, 5:49pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/3 "2014-04-08T17:49:51Z")

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Thank you Martin,

Does the file sink and source blocks work in case of a stream of packets  
(802.15.4).

Ruecan

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Sent from the GnuRadio mailing list archive at [Nabble.com](http://Nabble.com).

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**Author:** ![naeo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@naeo](https://www.ruby-forum.com/u/naeo)\
**Post date:** [April 8, 2014, 5:53pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/4 "2014-04-08T17:53:21Z")

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On Tue, Apr 8, 2014 at 11:48 AM, Ruecan [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> Thank you Martin,
> 
> Does the file sink and source blocks work in case of a stream of packets  
> (802.15.4).
> 
> Ruecan

Ruecan,

[http://gnuradio.org/redmine/projects/gnuradio/wiki/FAQ#What-is-the-file-format-of-a-gr\_file\_sink-How-can-I-read-files-produced-by-a-file-sink](http://gnuradio.org/redmine/projects/gnuradio/wiki/FAQ#What-is-the-file-format-of-a-gr_file_sink-How-can-I-read-files-produced-by-a-file-sink)

In GRC, look under Channel Models for the available models we have in  
the  
code.

Tom

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**Author:** ![naeo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@naeo](https://www.ruby-forum.com/u/naeo)\
**Post date:** [April 8, 2014, 5:58pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/5 "2014-04-08T17:58:02Z")

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Thanks.

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**Author:** ![naeo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/57b2e6/32.png) [@naeo](https://www.ruby-forum.com/u/naeo)\
**Post date:** [April 8, 2014, 7:19pm UTC](https://www.ruby-forum.com/t/using-grc-without-uhd/240325/6 "2014-04-08T19:19:14Z")

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Connect up a null sink and null source in parallel with the uhd blocks.  
Then right- mouse on the uhd blocks and select “disable”. This will  
gray-out the blocks and not compile them, but will leave them there  
preserving all your parameters.

@(^.^)@ Ed

Sent from my iPod