[hfsig] Performance of 24/192 soundcards? USB Soundcards

[Thomas Sailer]

On Tue, 2004-09-21 at 18:42, Anthony.N.Martin at marconiselenia.com wrote:

> sigma-delta ADCs. For digital radio, LF response is probably
> important to you, particularly I&Q matching of the LF response,
> and if it's determined by a pair of -20% +50% electrolytics...

I don't think you want to use the spectrum below roughly 1kHz for
serious high performance radio, as noise and interference go up towards
DC.

> fall over. I don't see anything in G3RUH that breaks properties of
> HDLC so it may be the G3RUH implementation is at fault. I don't
> think anyone has looped round a G3RUH via an adjustable HPF to get
> any hard facts anyhow.

Group delay variations?

Tom