I did some tidying up on my external receiver this morning and while the mast was down, I put the FA filter on my VNA to see the performance figures.
I actually swept from 1MHz to 3GHz but that’s far more than we need to know.
The actual bandpass is a little wider than I’d expect but that’s not a real problem. The important thing is that it has good attenuation on cellphone frequencies.
Insertion loss is far better than I was anticipating. It’s around 1.15 dB over the area we’re interested in.
So unless you’re running gain at absolute maximum, there should be no real disadvantage whatsoever in adding the filter.