[Discuss-gnuradio] Re: TvRx info

[Matt Ettus]

> Are there any application notes which give more
> information on what's inside, e.g. a functional block diagram?

None that I know of.  You can think of it as a dual conversion receiver,
with RF and IF gain controls.

> Does the TVRX module take the real IF output (converted to 5.75 MHz) into
> one A/D input and then down convert to I and Q channels in the FPGA?

Yes.  The other AD input is ignored.  This is determined by the mux
settings.  Normally you use 0xf0f0f0f0.  The F in F0 means feed the Q
input with zeros.  The 0 means feed the I input with ADC 0.  For a board
with IQ downconversion you would see something like 0x01010101.

> I'm still interested in developing a phased array capability.  Would it be
> possible to modify the tuner to accept a common oscillator?  Or, do you know
> of a likely candidate?

You'd have to cut open the can of the tuner and remove the crystal in
there.  You can then feed an FPGA output with a clock on it into the net
where the crystal used to go.  I haven't tried this myself.

Matt