Is my filter design funny or realistic?

I designed three simple FIR LPF filters with same number of taps,
cutoff frequency of Fbit, Fbit/2, Fbit/3.. Then I add the coefficients Bs
together. A is kept at 1. Finally coefficients B are still quite ok.

It appeared to reconstruct my received baseband signals pretty well.
The gain is not flat and not 1 but doesn't matter in NRZ coding.

Is it a working plan or is it a mad idea altogether?

Thanks!



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