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

[gary]

Any filter's group delay can be equalized by all pass filters.

Delay builds up at the filter corner. Since everything in the real world 
is causal, you add delay outside that corner frequency but in the 
passband to equalize it. This is to say, you can't remove delay, but 
just add it to flatten out the group delay.




On 3/17/2012 5:44 AM, Attila Kinali wrote:
> On Sat, 17 Mar 2012 10:15:17 +0000
> "Poul-Henning Kamp"<phk at phk.freebsd.dk>  wrote:
>
>> Either you need to characterize the exact behaviour of your filter
>> and build the necessary compensation for its phase/frequency behaviour
>> into your receiver, or you need a very flat filter (both freq+phase)
>> in order to reliably recognize the proper zero-crossing to track.
>
> BTW: how do you compensate for the filter characteristics of your
> magnetic loop antenna?
>
> 			Attila Kinali