Yeah, I understand it's not a practical thing in reality, this is mostly for a short-duration simulation which runs for a few K samples then stops. Obviously any real-world signal with any DC bias would rail this out.
I'm still surprised the integrate_x blocks allow a decimation = 1 since that effectively makes the block a pass-through. The block documentation could use some help here. I just requested a Wiki login and could probably make some edits to clarify this for the less-informed. I presume that's the point of requesting a Wiki login, anyway!
I had tried the IIR approach unsuccessfully at first (not really knowing their standard form, I guess), but just revisited it, and yes, I can make that work. Again, the documentation is pretty .. light, heheh... (
https://wiki.gnuradio.org/index.php/IIR_Filter). Probably not a big deal if you know DSP inside and out, I'm sure it's a standard thing, though.
Thanks again,
Joe