# Receive sensitivity of B200

**URL:** <https://www.ruby-forum.com/t/receive-sensitivity-of-b200/241202>\
**Category:** GNU Radio\
**Created:** [May 18, 2014, 11:50pm UTC](https://www.ruby-forum.com/t/receive-sensitivity-of-b200/241202 "2014-05-18T23:50:38Z")\
**Posts on this page:** 3\
**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:** [May 18, 2014, 11:50pm UTC](https://www.ruby-forum.com/t/receive-sensitivity-of-b200/241202/1 "2014-05-18T23:50:38Z")

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Hi, I use B200 with OpenBTS at 900MHz. I get very low range (about 10m  
only) and I identified that this is due to receive channel in B200.  
Changing rxgain between 0 and 70dB makes vey little difference. Does  
anyone know how the receive sensitivity of B200 compare with, for  
example, WBX?  
What could be the reason for this low sensitivity? uhd\_fft spectrum  
looks “normal” , in the sense that I do not suspect a broken LNA.

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**Author:** ![rlorimor](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/96bed5/32.png) [@rlorimor](https://www.ruby-forum.com/u/rlorimor)\
**Post date:** [May 18, 2014, 11:58pm UTC](https://www.ruby-forum.com/t/receive-sensitivity-of-b200/241202/2 "2014-05-18T23:58:00Z")

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On 05/18/2014 05:49 PM, Robert L. wrote:

> Hi, I use B200 with OpenBTS at 900MHz. I get very low range (about 10m only) and  
> I identified that this is due to receive channel in B200. Changing rxgain between  
> 0 and 70dB makes vey little difference. Does anyone know how the receive  
> sensitivity of B200 compare with, for example, WBX?  
> What could be the reason for this low sensitivity? uhd\_fft spectrum looks  
> “normal” , in the sense that I do not suspect a broken LNA.
> 
> * * *
> 
> 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)

Are you on the correct antenna port?

The B2xx RF section is roughly the same noise figure and total gain as a  
WBX.

–  
Marcus L.  
Principal Investigator  
Shirleys Bay Radio Astronomy Consortium

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<div class="post-metadata">

**Author:** ![rlorimor](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/96bed5/32.png) [@rlorimor](https://www.ruby-forum.com/u/rlorimor)\
**Post date:** [May 19, 2014, 12:10pm UTC](https://www.ruby-forum.com/t/receive-sensitivity-of-b200/241202/3 "2014-05-19T12:10:34Z")

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Are you rx’ing only with the B200, or tx’ing too?

If you have a VHF antenna, you can tune it to your local FM radio  
stations  
and you will see them on uhd\_fft if things are set up correctly. Adding  
to  
what Marcus said, check the correct LED is lit to verify you’re using  
the  
right antenna port.

M