On Fri, 13 Aug 2010, Matt Ettus wrote:
On 08/13/2010 12:14 PM, Daniel Halperin wrote:
On Tue, 10 Aug 2010, Matt Ettus wrote:
> When using a BasicRX or LFRX with the PGA set at 0dB gain (USRP1
> only), +10dBm is full scale on the ADC. On the USRP2 full scale on the
> ADC is full scale when it gets back into gnu radio. On the USRP1 full
> scale on the ADC is (1.67/2) times full scale due to the gain of the
> CORDIC.
>
> +10dBm = 2Vpp = 1 Vpeak = 0.7 Vrms
>
> With other daughterboards you will need to calibrate at the frequency
> of interest.
Thanks, that's helpful. However, I can't quite make the math work:
P = V^2/R ; 0.01 W = 1^2 / R ; R = 100 Ohms.
RMS power = Vpeak^2 / (2*R)
RMS power = Vrms^2 / R
... so as long as I don't send a pure DC signal (which presumably I can't
b/c there will be filters so the device doesn't support it anyway) I
should be using RMS power to account for the carrier wave variation?
Makes sense.
Thanks,
Dan
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
