Burbank, Ca, BUR had a glide slope that showed on glide slope no matter where you were. We did the normal crossing altitudes and realized the GS was inop but no flags and centered. It was VFR so no problem but the airliner behind us got a low altitude alert from tower so the airliner said we are right on GS and tower said the GS is notamed inoperative. I guess it was due to maintenance but the ATIS for BUR is unreadable until low altitude because of a same frequency up north blocking it.