Re: [Discuss-gnuradio] TX characterisation of USRPN210 with SBX daughter

Hi Ron

Sorry about that. Please find attached the modified graph.

The two curves seems more consistent in this graph.

I am assuming the DAC should have reached saturation at Ampl =1. However my reading don't seem to depict that so well.

Would it have been better to started at such lower values of Amplitude?

I understand for a SBX board, the Tx'd o/p power range is +16 -20 dbm ( 1.5 to 2.2 V) with a 32 dB gain control range, which I understand that I can vary the Tx'd power from -16 dBm to +16 dBm (0.035 V ~ 1.5 V). Is my understanding correct?. So should I vary my ampltude from 0.035 V untl 1.5 V? is that within the usrpN210's working levels?

Thanks

On Mon, Mar 24, 2014 at 3:48 PM, Ron Economos [via GnuRadio] <[hidden email]> wrote:

The graph doesn't match your numbers.

Ron

On 3/23/2014 8:56 PM, Gayathri Ramasubramanian wrote:

> Hi,
>
> I am trying to characterize the TX and RX characteristics of USRPN210 with a
> SBX board.
> I have tried one test : Amplitude Variation effects, by varying the
> amplitude in steps and finding out the o/p power through spectrum analyser.
> The foll are the readings I got.
> Amplitude level 921.25 MHz 2.45625 GHz
> 0.0625 -49.18 -60.97
> 0.125 -43.2 -55.05
> 0.25 -37.25 -49.09
> 0.5 -31.24 -43.05
> 1 -25.38 -37.13
> Amplitude change 921MHz 2.456GHz
> 1 to 0.5 5.86 5.92
> 0.5 to 0.25 6.01 6.04
> 0.25 to 0.125 5.95 5.96
> 0.125 to 0.0625 5.98 5.92
>
> when i ploted the graph in excel, (O/p power Vs amplitude), i got two almost
> linear curves, but their was a big difference in the 2 lines @ 921.25 MHz
> and 2.45625 GHz (as seen above) at the start and if extrapolated could
> converge at a higher ampl and o/p power.
> I was not sure about my results and was looking to see if some one could let
> me know if these values look within the normal expected behaviour? if not,
> please let me know what is the normal expected behaviour.
> I am new to USRP and GRC programming and doing this for a project.
> <http://gnuradio.4.n7.nabble.com/file/n47157/Oppower_vs_ampli.png>
>
>
> Thanks in advance
>
_______________________________________________
Discuss-gnuradio mailing list
[hidden email]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

If you reply to this email, your message will be added to the discussion below:

http://gnuradio.4.n7.nabble.com/TX-characterisation-of-USRPN210-with-SBX-daughterboard-tp47157p47165.html

To unsubscribe from TX characterisation of USRPN210 with SBX daughterboard, click here.
NAML

From:	Gayathri Ramasubramanian
Subject:	Re: [Discuss-gnuradio] TX characterisation of USRPN210 with SBX daughterboard
Date:	Mon, 24 Mar 2014 14:59:30 -0700 (PDT)