Hi David, Freedv works fine for me with one sound card (rx only), I just tested it again using the internal sound card of my laptop. Select "none" for both sound cards on the "tx tab".
It also handles 8kHz 16 bit wave files from the various options on the Tools menu. Cheers, David On Tue, 2012-12-25 at 12:04 -0800, David Ranch wrote: > > Hello Everyone and Merry Christmas! > > > > Your filters are supposed to be useful for rejecting other signals > > > when you're using CW or SSB. But it's not clear to me that they > > > really do much when you're using software defined radio (which of > > > course this is). SDR can provide software filters that are as > > > close to perfect as possible. However, the crystal or mechanical > > > filters in your radio add ringing and non-linearity to the signal, > > > and thus may actually make things worse when the result is fed to > > > an SDR. > At least for the FT950, the 3khz roofing filters use block out > adjacent strong signals are understood to be pretty useless: > > > http://ac0c.com/main/page_ft2k_roofing_filters_project_overview.html > > That's why I had made the previous comment about maybe considering a > different frequency. Maybe it just a matter of my radio not being up > to handling this duty. Dunno yet but I do know in that specific > situation, the FreeeDV transmission was impacting my Digital SSTV > decode on 14.233. I would personally think that an FT950 is maybe a > middle of the road radio and others will probably have similar > problems that I did. Dunno. > > > So, before we decide to center anywhere, we should determine 1) do > > filters consistently help or should they just be defeated and 2) are > > filters generally centered at 1 kHz or is that just true for a few > > radios? > Next time I run into this situation, I'll narrow down the filters as > best as I can to minimize any adjacent interference and see if it > works well enough. Btw, the "sweet spot" of radios can be different > on the make and model so I would encourage the FreeDV group to > consider supporting different center points than just a fixed 1500hz. > Here is a decent post about this: > > > http://lists.contesting.com/archives//html/RTTY/2011-04/msg00108.html > > > Btw, per a previous recommendation from David Rowe, I installed FreeDV > for Windows and was able to decode maybe 20% of the signal I captured! > Very slick but I guess signal I captured through my dipole wasn't > strong enough to get a better decode (it was a bit overdriven too). > Adam also posted to the list on using the "ecasound" program which > might be able to post-process the raw files and change the center > point of the WAV files I captured. I looked at doing this with sox > and it's "pitch" feature but that command does everything in ‘cents’ > and 'semitones' and I have NO clue of what those are! > > > One thing worth noting fro David Witten's fantastic FreeDV UI: I could > never get the Windows program to play back my "raw" audio files until > there where two sound cards installed *and* configured. Without the > two soundcards present, either the FreeDV program complained about an > invalid configuration or it crashed. It would be been nice if FreeDV > for Windows could support just one sound card for test scenarios like > this. It would also be slick if it could handle WAV files.. I can > convert them with Sox but I don't know if the average Windows user > would know how. Maybe Audcity can do it? Dunno. > > Anyway.. kudos to everyone on getting the project so far! It's > amazing to see how far it's come and I look forward to playing with it > on Linux when it's ready! > > 73s > --David > KI6ZHD > ------------------------------------------------------------------------------ > LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial > Remotely access PCs and mobile devices and provide instant support > Improve your efficiency, and focus on delivering more value-add services > Discover what IT Professionals Know. Rescue delivers > http://p.sf.net/sfu/logmein_12329d2d > _______________________________________________ Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
