Reducing RF noise interference?
 

Hi all. I recently purchased the Sony AN-LP1 active antenna from Universal
Radio. As I have posted previously, due to my apartment dweller status, I
cannot use an outside antenna. So going with a powered indoor seemed like a
good idea. It seems to work well with my Grundig YB-400PE, but it does tend
to raise the electrical noise level up quite a bit on the audio, making some
otherwise decent catches unlistenable. Is there any suggestions you folks
have to reduce the amount of noise that the antenna is picking up? Maybe
some kind of filter attachment or something? Obviously an apartment building
is not the ideal place for shortwave listening, but I'm stuck here for now.

Thanks in advance.