[Discuss-gnuradio] Questions about the 4937

[Alan Gray]

Just a few questions about the Microtune 4937 module that seems to be in 
general usage. I've done a little looking around and have pretty failed to 
find anything even close to similar available so I'm guessing it's probably 
the easiest option for IF conversion. My questions are as follows:

1) Has anyone in Australia or the surrounding region obtained one of the 
modules? If so, would you mind sending me some details (Who you went 
through, cost, time taken for it to arrive etc). Unfortunately it appears 
that there is no Australian contact for Microtune so I may have to ship 
from overseas.

2) After noting that the eval board from Microtune is rather expensive, it 
looks like I'll be building my own, I've taken a look at the schematic 
provided and ran into the following problem: My A/D has an input impedance 
of 500 ohm, not 50 ohm. I'm not thoroughly conversant with the hardware 
just yet, but I'm thinking this might be a problem. So, how much trouble 
and I going to get myself into trying to redesign the schematic to allow 
for the differing input impedance. Is it as simple as replacing the 50 ohm 
resistor on the output of the OPA691? (hey, I gotta hope for an easy way 
out) or will I have to work on something more complex?

Any suggestions will be most appreciated

Alan