Interesting the ESI sound card, I'll check where to buy one. Useful to sample VLF time and frequency signals directly.
On Fri, Mar 16, 2012 at 7:26 AM, Dave Brown <[email protected]> wrote: > EMU 0202 or 2020? I know what an 0202 is but what is a 2020? > DaveB,NZ > > ----- Original Message ----- From: "Demian Martin" <[email protected]> > To: <[email protected]> > Sent: Friday, March 16, 2012 6:53 PM > Subject: Re: [time-nuts] broadband MPX signal stereo > > > > I have tested a number of soundcards and while the EMU 2020 has issues >> (serious jitter and noise from the USB interface) I can recommend the ESI >> Juli@ as having flat response and good SNR up to 90 KHz. It's a PCI >> card, no >> USB. I have measured the performance of FM MPX adapters and tested FM >> Transmitter performance with one. You get 24 bit at 192 X 2 continuously >> as >> long as you want. With some simple pre-filtering and gain you should be >> able >> to get some 60 KHz signal at very low levels. With a deep FFT I get to >> -130 >> dBFS easily. With the demo board for the AKM AK5345a I am getting better >> than -160dBFS. That has SPDIF out. Depending on the filter selection, most >> chips have a flat option, there is no significant phase shift up to >> frequencies close to the cutoff. >> >> I have tried and dumped a number of other sound cards that were dead ends. >> The ESI Juli@ is usually around $120. >> Demian >> ______________________________**____________ >> Chris Albertson writes: >> >> Some audio interfaces have a low pass filter to cut off at about 20KHz >> but many don't have the filter. The user manual should list the >> bandwidth of the interface. Mine claims to be flat out to 40KHz. But >> it varies. >> >> For example the EMU 2020 user manual reads >> "Frequency Response (min gain, 20Hz-20kHz): +0.0/-0.07dB" >> But what happens after 20KHz? The specs don't say. You have to test >> it yourself and see. >> >> >> >> >> >> ______________________________**_________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/** >> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> and follow the instructions there. >> > > > ______________________________**_________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
