[time-nuts] WWVB BPSK Receiver Project? (fwd)

[Marek Peca]

> Yes, in order to equalize group delay, you need to know what to equalize. But 
> with an educated guess as to the system response, he could get close.
>
> All this said, in 2012, I would rather the amplifier be simple gain, the 
> inductor not loaded with capacitance and the filtering done past the 
> amplifier. We aren't living in the era of 3 transistor circuits.
>
> When delta-sigma converters came on the scene. I wisely found new design 
> skills. [They replaced much analog filtering.] So better just to do the 
> filtering in DSP IF there is no critical power budget.

This may not be true, if you have some strong interference at the ferrite 
rod input. Of course, if it would be strong and near the signal frequency, 
it will not be attenuated much even by the 2nd order LC circuit, indeed.

However, for f0=77.5kHz and B=1kHz, the LC circuit with Q=40 gives phase 
error over specified bandwidth about +-0.5deg p-p. Does such a phase 
non-linearity bother you?


Marek