# Clock block slow in position satellite calculation

**URL:** <https://www.ruby-forum.com/t/clock-block-slow-in-position-satellite-calculation/230311>\
**Category:** GNU Radio\
**Created:** [June 10, 2014, 9:26am UTC](https://www.ruby-forum.com/t/clock-block-slow-in-position-satellite-calculation/230311 "2014-06-10T09:26:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\
**Post date:** [June 10, 2014, 9:26am UTC](https://www.ruby-forum.com/t/clock-block-slow-in-position-satellite-calculation/230311/1 "2014-06-10T09:26:47Z")

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Hello,

I have this flowgraph in GNURadio:  
[![](https://i1281.photobucket.com/albums/a515/Carlos_Alberto_Ruiz_Naranjo/esque_zpsd89166da.png) ](https://i1281.photobucket.com/albums/a515/Carlos_Alberto_Ruiz_Naranjo/esque_zpsd89166da.png)

→ Green: calculates the signal delay of a satellite.  
 → Yellow: a clock with a second precision.

If I run the clock separately I can see in the WX GUI Number Sink that  
it works. (0,1,2,3,4… each second)  
But if I run the entire flowgraph I can see in the WX GUI Number Sink  
that clock becomes very slow. (0,1,2,3,4… each 2 second approximately)

Why is this? Any solution?

Thank you 😉

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**Author:** ![caruiz.ext](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/7ba0ec/32.png) [@caruiz.ext](https://www.ruby-forum.com/u/caruiz.ext)\
**Post date:** [June 10, 2014, 9:53am UTC](https://www.ruby-forum.com/t/clock-block-slow-in-position-satellite-calculation/230311/2 "2014-06-10T09:53:22Z")

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Hi!  
You shouldn’t use so many throttles in one flow graph; throttle limits  
the number of samples going through in a given time, and as soon as the  
“upstream” blocks have filled their output buffer, they will be limited  
in throughput, too.  
So I guess this is the effect of throttles blocking each other; however,  
I don’t really understand what’s happening inside your flowgraph, so  
this is a lot of guesswork.

Greetings,  
Marcus