I and Q signals depend on their phase relationship in order for it to work correctly, something like a notch filter will mess up that relationship and render them useless. Besides the main point of a QSD receiver is for the CPU to do the filtering, which it can do 10X better than any discrete filter can. Keep the hardware simple, do the complex in the CPU.
At 07:15 PM 4/3/2006, you wrote: > Man, this is an active email group, but thats good, I got lots to > read and very interesting, > > Ken brought up the question of whether you can notch >the I and Q signals in the audio chain of a receiver? >I have had receivers with i.f. notch before and as far >as I understand the two phase shifted signals you should >be able to do this. > > The two signals although phased 90 degrees from each >other still are sine wave components of frequency and >amplitude. Being generated by a transmitter somewheres >on the airwaves. I see no reason why a notch filter >would not work in the audio chain of the two port signals >I and Q. The reasoning behind this is that the I and Q >signals are in the audio pass band and are sinewave >components having various frequencies. A CW tone will >appear somewheres in the pass band when a CW signal is >present and it will be located at a certain frequency >and so a notch filter in the audio pass band should be >able to notch it out if it is undesired in the pass band. > > At least thats how I see it? > > Of course such a notch would have to be very narrow >in order to work in the desired audio pass band. If >too wide it would take out too much band width. So Op >Amps would accomplish this. > > I am not a software desinger, just a radio tech thats all. >I am looking at the circuits. I can't even imagine the software, >I look at learning Java and Python and well its scary. I have tried >my hand at artificial intellegence mark up language though (aiml), I >have a few of those robots like Alice Bot. > > Now this is my theory of the the analog circuits and well >it will take some experimenting to see if the audio notch filter >idea will work. As far as I understand it, it should work. > >Dan > > >_____________________________________________________________________ >Call Anyone, Anytime, Anywhere in the World - FREE! >Free Internet calling from NetZero Voice >Visit http://www.netzerovoice.com today! > > > > > > > >Yahoo! Groups Links > > > > Cecil Bayona KD5NWA www.qrpradio.com I fail to see why doing the same thing over and over and getting the same results every time is insanity: I've almost proved it isn't; only a few more tests now and I'm sure results will differ this time ... [Non-text portions of this message have been removed] 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/
