Undersampling is exactly what I had in mind. However, in my ardour, your point about the S&H window slipped my attention. ;-)) Pity!
P-T At 12:43 31.10.2005, you wrote: >Per-Tore Aasestrand wrote: > > Couldn't that converter also sample the 455 kHz directly? > > > > We are dealing with a BW of just around 10 kHz. The filtering of the signal > > is usually also quite good. Some receivers have an ultimate rejection of > > out-of-band signals of more than 90dB. By choosing the sample rate > > carefully, one ought to be able to avoid troublesome aliasing. Or? > > > While it is true that you can sub-sample, taking advantage of the > so-called Nyquist zones, if your signal is bandwidth limited, it must not > be forgot that the aperture width of the ADC must be commensurate with > the real frequency of the signal. I don't know if that sigma-delta > converter has a sample-and-hold front end with a sample width short > enough for 455 kHz. After all, it was meant for sampling audio signals. > >73 Alberto I2PHD > > > > > >Yahoo! Groups Links > > > > +-----------------------+------------------------------+ | Per-Tore Aasestrand | E-mail : [EMAIL PROTECTED] | | P.O. Box 1708 Nordnes | Voice : + 47 - 55 32 32 35 | | N-5816 Bergen, Norway | Mobile : + 47 - 92 04 44 76 | +-----------------------+------------------------------+ ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/ELTolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
