Re: [Discuss-gnuradio] TVRX data interface to USRP board (VINN_A, VINP_A; VINN_B, VINP_B)

[Stephane Fillod]

On Mon, Sep 26, 2005 at 02:56:18PM +0800, address@hidden wrote:
>          In the module interface, there are two RF data differential pairs 
> from
> RF board to the USRP board: VINN_A, VINP_A; VINN_B, VINP_B. 
> If there are two individual RF tuners on the RX board, I think they each use 
> one different pair, like the picture below for basic RX board.
> http://www-personal.engin.umich.edu/~anastas/gnuradio/usrp_gen.eps
> But how about the TVRX board? From what I see from the python code,
> only one ADC is used. Is one of the differential pairs left open
> or both of them connect from the same RF tuner output? If the answer is 2),
> under what condition would this be used (I/Q sampling) for this tuner?

IANAEE, but reading the schematics[1], it looks like only VINP_A/VINN_A
are connected (to out+/out-). So I would say answer 1).

[1] http://www.ettus.com/Download.html

Now this makes me think, why the left unused pair VINN_B/VINP_B has not
been used as an extra single basic RX on the TVRX board?
Matt, Eric, can the TVRX still be moded?

-- 
Stephane