I also checked the links from Tom and John about Forsters ideas respectively patents.
Patent http://gb.espacenet.com/search97cgi/s97_cgi.exe?action=View&VdkVgwKey=GB2295513A&DocOffset=1&DocsFound=3&QueryZip=%28edward+AND+forster%29+%3CIN%3E+pa&Collection=dips&SearchUrl=http%3A%2F%2Fgb%2Eespacenet%2Ecom%2Fsearch97cgi%2Fs97%5Fcgi%2Eexe%3Faction%3DFilterSearch%26QueryZip%3D%2528edward%2BAND%2Bforster%2529%2B%253CIN%253E%2Bpa%26Filter%3Dgb%252Fen%252Fespacefilt%252Ehts%26ResultTemplate%3Dgb%252Fen%252Fresults%252Ehts%26Collection%3Ddips%26ResultStart%3D1%26ResultCount%3D10&ViewTemplate=gb/en/textdraw.hts&ViewErrorTemplate=gb/en/incerror.hts&DocsFound1=3&BeginHighlight=%3Cspan%3E&EndHighlight=%3C/span%3E&HLNavigate= --> Thanks Tom ! E.C. Forster Page http://ecforster.netfirms.com/AMRecdoc/Doc1.html http://ecforster.netfirms.com/GB2295513/Doc1.html --> Thanks John ! My experimental homebrew receiver "HDR-2005" now consists of LPF-QSD-PolyphaseFilter-SSBdemod-LPF-(SCAF BPF)-AFamp. I work just now on a new SCAF BPF and notch-filter. But I am absorbed in thought about AM analog hardware demodulation of the I/Q channels ! As soon as the time and the XYL permit it, I try to understand Forsters patent or I found an other possibility ;-) Chris --- In [email protected], Frank Eory <[EMAIL PROTECTED]> wrote: > John, > I checked your links. Looks interesting. I don't quite see the ^2 > function at http://ecforster.netfirms.com/GB2295513/fig2.gif which is > used for the computation of i^2 and q^2 and I don't get the square root > either yet. It looks more like two diodes in series, which has an > exponential voltage-current function, which is not that far. I still > don't see the sqrt yet. I just received a TI quad switch and a low > noise op amp that I'll hook up single ended RF to double ended input to > the op amp, essentially like flexradio. The only difference is that I > have a quad switch like the IC used in softrock40. I'll be able to try > out that idea in the patent. Chris should be able to try it faster > since his rig is already done. > > For testing, I think I'll use a ad9850 DDS which I'll modulate with > 1kHz maybe with a SA602 mixer. (I might try out a switch modulation, > just like the TX side of flexradio). I'll make attenuate it down and > check the sinad for 10dB. I'll use an LMS to adjust the phase of a 1kHz > signal, subtract it to the demodulated audio and calculate the noise > and signal powers. I will then have a sensitivity in uV for the rig. > With a little work, I could fft the noise and demodulated signals too. > > Frank ------------------------ 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/
