RE: [Discuss-gnuradio] Parallel Port Interface

[Ettus, Matt]

> Do 96ksample/s cards have 48kHz of actual bandwidth or will 
> some analog filters need to be disabled?

They're pretty close.  I've seen 44 to 46 kHz quoted.  Leif Asbrink gets 90+
kHz total.  Some cards might have narrower filters in front, but the
majority don't.

> How wide of a hole surrounding 48kHz will this scheme have?

Most sound cards go down to about 10 or 20 Hz, so you would have a 20 to 40
Hz hole.  You might be able to remove the DC block, but it isn't worth the
effort.

> Can the sampling clock for a sound card be derived externally?

On some of them.  Why do you need that?

> Your scheme gives me another idea to use the sound card: use 
> a pair of track/hold devices to sample the raw analog 
> voltages, one at a time, at 192kHz and offer these 
> alternating time points to the two channels of the sound card 
> at 96kHz, generating the timing externally as I already have 
> as a requirement.

I don't see the point of this, and I doubt it would perform better.

Matt