[Discuss-gnuradio] 192KHz sound card experience: WWVB, etc

[Marcus D. Leech]

I finally installed a M-Audio Audiophile 192 sound-card on my F14 system 
today, further to my efforts to make
  a WWVB (and DCF77 and any other time station that uses 
broadly-similar mechanisms) receiver based on
  little more than a high-rate sound-card, pre-amp, and loop antenna 
(and of course, Gnu Radio).

I have a similar set-up for doing SID detection on VLF, using an 
external 96KHz USB sound-card--a Creative X-Fi USB.

What I've found is that the M-Audio internal 192KHz card has a roughly 
10dB higher noise floor (or put another way,
  a 10dB poorer SNR) than the external sound sysem.

The M-Audio Audiophile 192 uses a 24-bit ADC and can sample at 192KHz.

I ended up having to turn up the gain on my pre-amplifer, in order to 
compensate for the much-poorer noise performance on
  the Audiophile 192.

The way things are now, I can't "see" WWVB in the spectrum.  I'll see 
how it is tonight, but it sure doesn't look to "be there".
  This is at least consistent with my LaCrosse WWVB-synchronized 
digital clock that I have, which has *never* been able to
  get a lock on WWVB the entire time I've lived in this house.

I may look into the SDR-Widget system (Thanks, Patrick Strasser!), since 
it boasts better performance than most other
  192KHz sound systems out there, and is tailored to narrowband SDR work.

--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org