Ignore this, this was a answer to someone else's question about a modified version to generate Quadrature over a wide range of frequencies.
At 03:25 PM 4/11/2006, you wrote: >The input transformer is there just to isolate the input signal, it >has nothing to do with the Quadrature generation. It isolates the >input from the bridge which is biased at 1/2 VCC so we can get away >with using a single power supply on the comparators and op-amps. > >If you are talking on my schematic QSD2 you will see that I'm >detecting the zero-crossing of the signal across each side of the >bridge of the two RC networks. Both signals shifts with frequency but >the difference stays at 90 degrees. Amazingly that relationship holds >for several bands. > >I had a more refined version, but dumb me I thought I had a backup of >the schematics at home and deleted them, then I discover later that I >didn't have a copy. I will try to redo the work, but right now things >are going very slow. Lately I've not not been feeling so good so >I'm barely keeping up with just going to work. But things are >improving, I've not had any irregular heartbeats since last Thursday >that I could detect, so I'm beginning to feel a little better. > >In a week or two I'll get back to it recovering the schematics full >time. I have a print out but I don't have the better LTSpice models >that they use, so I'll have to recreate them again. The most advanced >"QSD6" was a complete multi-band transceiver, that I was going to >build. I wanted to run a few more careful simulations before I create >PCB's and send them out. > > >At 02:32 PM 4/11/2006, you wrote: > >KD5NWA: > > > > The transformer seems simple enough, especially with a fixed > > mixing frequency. I found it being used with a vfo for 40 meters > > and it does look allot like a balun or transmission line > > transformer. I got an email on a file to check out a twisted pair > > idea here today. > > > > Also, there is way to split a signal off into two for I Q with a > > resistor in one line, equal in resistance to either a capacitor or > > inductors reactance in the other line. The reactance's phase shift > > voltage and current by 90 degrees in the one line. It appear that > > a single capacitor or coil in the other line will shift ther pahse > > 90 degrees but only if the frequency of operatiuon is fixed or limited. > > > >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 > > > > 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/
