David, A Tayloe detector is of great utility in the "real world" of hardware as a way to get a quadrature baseband signal from a real passband signal. In the DSP world things are much easier!
If you have a real-valued signal (i.e., an audio stream), you first convert it to a complex (quadrature) signal. You can do this in two ways. The first way is more obvious: use a float-to-complex block and feed the real part into the real input. Put a constant "0" into the imaginary input. The result will have both positive and negative frequencies in it -- plot it on a spectrogram! You can then filter out the negative frequencies with a complex bandpass filter. Or don't, if they don't bother you: you can always filter them out with a lowpass after mixing. More simply, but less obviously, you can use a Hilbert filter to create a quadrature signal from a real one while eliminating (most of) the negative frequencies. Once you have a complex signal, then you mix it with a complex sine wave at the center frequency of your signal of interest. Mixing is just multiplication, so use a multiply block with one input as your signal, and one input the complex sine wave (i.e., from a "Signal Source" block). Remember to mix with a *negative* frequency, as you're moving your signal *down*. No NE602 needed! You'll have your complex signal at baseband and can now filter, demodulate, or do whatever you want to it. Nick On Fri, Aug 12, 2022 at 10:43 AM david vanhorn <kc6...@gmail.com> wrote: > Ive been wrestling with this for a while, and im not even seeing how to > get started implementing a Taylor detector in gr. > > Is it even possible? >
