[TowerTalk] 40 meters Interference

[Luciano Nachif]

Hello folks!
I installed a 40-2Cd Cushcraft two elements 40 meters yagi on a tower recently.
 
I was quite impressed by those strong noises (S-9) every 24 KHz. It seems to come via the antenna as if I take the cable off the female connector back on the radio the annoying signals stop bugging me. I tried to hear it with a short 3 foot wire but it failed.
 
I suspect this might be the same kind of issue related either to a Phillips TV set my parents had in their home or the cable TV itself, but I'm not sure.
 
Any comments or clues? How should I trace that to get it if fixed? Any pages that I should red to get acquired to the problem?
 
I appreciate your help.
 
73,
Luciano PT9KK