Thanks Josh, y Yes the analog BPF has a 3dB BW of about 100 kHz, 40dB down at +/- 1 MHZ which is the aliasing point of the ADC (i.e a signal at 9.5 MHz will be aliased right on top of our wanted signal).
I am also considering a simple crystal filter at this point. However we would like a 100 to 200 kHz IF bandwidth so we can do 2 channel diversity rx. Good point taken about the shielding! Cheers, David On 26/02/15 08:12, Joshua Mesilane wrote: > Hi David, > >>From a layout point of view, because you're using an IF, that IF should have >>fairly good filtering on the output of the mixer, say +-96khz band pass to >>give you 192KHz spectrum and also the mixer and filter be shielded from >>outside sources (under a full shield). > > As for input filtering, you probably want selectable band pass filters for > the bands in question, again these should be shielded from outside sources. > > It's looking good! > > Cheers, > Josh > > ---- > VK3XJM > 0416 039 082 > http://www.zindello.com.au/ > [email protected] > >> On 25 Feb 2015, at 12:46, David Rowe <[email protected]> wrote: >> >> Hello, >> >> To support VHF FreeDV developments I've been working on a really simple >> and very open SDR architecture for VHF radio: >> >> http://www.rowetel.com/blog/?p=3884 >> >> Glen and Matt - would appreciate you suggestions on appropriate input >> BPF filtering and a VHF mixer. Also pls let me know if you see any show >> stoppers in this architecture. >> >> Cheers, >> >> David >> >> ------------------------------------------------------------------------------ >> Dive into the World of Parallel Programming The Go Parallel Website, >> sponsored >> by Intel and developed in partnership with Slashdot Media, is your hub for >> all >> things parallel software development, from weekly thought leadership blogs to >> news, videos, case studies, tutorials and more. Take a look and join the >> conversation now. http://goparallel.sourceforge.net/ >> _______________________________________________ >> Freetel-codec2 mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming The Go Parallel Website, sponsored > by Intel and developed in partnership with Slashdot Media, is your hub for all > things parallel software development, from weekly thought leadership blogs to > news, videos, case studies, tutorials and more. Take a look and join the > conversation now. http://goparallel.sourceforge.net/ > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
