On Tue, 10 Aug 2010, Matt E. 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 V)^2/R ; R = 100 Ohms.

But we’re using SMA connectors which are 50 Ohms right? Or should I be

putting 1 Vpeak I *and* 1 Vpeak Q and getting the 100 Ohms from the

combination of the two 50 Ohm connectors?

Thanks,

Dan

(forgot to reply all first, sorry for the double-msg Matt)