# LimeSDR’s maximum transmitting power

**URL:** <https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659>\
**Category:** LimeSDR\
**Created:** [30 October 2020 15:31 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659 "2020-10-30T15:31:51Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![amya121](https://avatars.discourse-cdn.com/v4/letter/a/a587f6/32.png) [@amya121](https://discourse.myriadrf.org/u/amya121)\
**Post date:** [30 October 2020 15:31 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/1 "2020-10-30T15:31:51Z")

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![LimeSDR_transmit_power](https://canada1.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/4/4c72bd5c0ae9d5469a603eb52915e38a4fc07b95.png)  
For the maximum transmit power for LimeSDR, the output power I measured (using a power meter) is close to 5dBm at 1 GHz when using TX output 1. Furthermore, my maximum transmit power for my LimeSDR is consistently 10dBm under what the graph shows. Any ideas as to why? Also, is this something I should be concerned about?

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**Author:** ![andrewback](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@andrewback](https://discourse.myriadrf.org/u/andrewback)\
**Post date:** [31 October 2020 14:12 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/2 "2020-10-31T14:12:54Z")

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Where did you get this graph from?

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**Author:** ![amya121](https://avatars.discourse-cdn.com/v4/letter/a/a587f6/32.png) [@amya121](https://discourse.myriadrf.org/u/amya121)\
**Post date:** [2 November 2020 18:04 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/3 "2020-11-02T18:04:30Z")

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My bad!

> [@LimeSDR’s maximum transmitting power at different frequencies](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power-at-different-frequencies/1649/2):
>
> Hello Shao, Please find the maximum transmit power (CW) for LimeSDR in the attached graph below (note that X axis is not logarithmic). The output power is close to 15dBm at 950MHz when using TX output 1. [LimeSDR\_transmit\_power] Hope this helps, Karolis

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**Author:** ![andrewback](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@andrewback](https://discourse.myriadrf.org/u/andrewback)\
**Post date:** [2 November 2020 20:56 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/4 "2020-11-02T20:56:07Z")

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Thanks. What software are you using to generate a signal? And what is the gain configuration? Might be easiest if you could save an INI file in LimeSuiteGUI, share this and perhaps @Karolis could take a look.

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**Author:** ![amya121](https://avatars.discourse-cdn.com/v4/letter/a/a587f6/32.png) [@amya121](https://discourse.myriadrf.org/u/amya121)\
**Post date:** [2 November 2020 22:43 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/5 "2020-11-02T22:43:07Z")

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I am using GNU radio to generate the signal at maximum gain (70).

 ![gnuradio](https://canada1.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/5/565eeea56ac8270be001d43dbdab022f2cb9a2ff.png)

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**Author:** ![mzs](https://yyz2.discourse-cdn.com/flex034/user_avatar/discourse.myriadrf.org/mzs/32/2678_2.png) [@mzs](https://discourse.myriadrf.org/u/mzs)\
**Post date:** [3 November 2020 04:25 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/6 "2020-11-03T04:25:02Z")

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If you are sending data to real hardware that throttle block should be removed. If you are not sending it to real hardware then you do need it.

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**Author:** ![amya121](https://avatars.discourse-cdn.com/v4/letter/a/a587f6/32.png) [@amya121](https://discourse.myriadrf.org/u/amya121)\
**Post date:** [6 November 2020 19:50 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/7 "2020-11-06T19:50:27Z")

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I removed the throttle block and I am still getting 10dBm under what the graph shows. Any ideas what else it could be?

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**Author:** ![evansun](https://avatars.discourse-cdn.com/v4/letter/e/3d9bf3/32.png) [@evansun](https://discourse.myriadrf.org/u/evansun)\
**Post date:** [6 November 2020 20:24 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/8 "2020-11-06T20:24:24Z")

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> [@andrewback](#):
>
> Thanks. What software are you using to generate a signal? And what is the gain configuration? Might be easiest if you could save an INI file in LimeSuiteGUI, share this and perhaps @Karolis could take a look.

Hi, I’m one of the team members working on this project. Settings are pretty the default I believe - [here](https://drive.google.com/file/d/1Ho_5Pvw6wqstDSG6Eu93bdGFaC1XuIZF/view?usp=sharing) is the debug dump of the configuration.

We’re using GNU Radio to interface with the LimeSDR. I’ve attached the spectrum analyzer output. Note that a 30dB attenuator was added in-line, so the actual power hovers just around 5dBm.Gain was set at 70 in the GNU Radio block, which I believe correlates directly to dB. The maximum value according to documentation is 73, which correlates to about 8dBm.

Let me know if there’s any other information I can provide.

 ![LIME](https://canada1.discourse-cdn.com/flex034/uploads/myriadrf/original/2X/9/970681aeff1e42e88d6068d5d2f73fddf35b1baf.png)

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**Author:** ![andrewback](https://avatars.discourse-cdn.com/v4/letter/a/22d042/32.png) [@andrewback](https://discourse.myriadrf.org/u/andrewback)\
**Post date:** [7 November 2020 11:11 UTC](https://discourse.myriadrf.org/t/limesdr-s-maximum-transmitting-power/6659/9 "2020-11-07T11:11:34Z")

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@Zack, could you take a look, please.