So... my wife went to sleep early, I do not blame her, I woke her up pretty early. So now I'll wait until my tenants go to sleep and then I'll get out of here. But I do not know what will happen once that I do it so better post my only discovery before something letal happens to me.
My way of operation was to draw the operator symbol in a big canvas and put in one side of the park in late night hours and let some cameras hidden in the trees filming that side and the opposite side of the park. I thought that it would be a nice opportunity to research wich electric devices does slenderman fuck up with, but the results showed that it jams every single one of them, but not every time.
So... I swapped the place of the canvas every day, and I went for the tapes or files every morning... one of my cameras was stolen but that's another story. He always went to the side of the park where the operator symbol was but keep his distance. Everyday he got closer and closer to the canvas, he never standed right besides it but he went pretty close. So I conclude that it's effects run out pretty quickly.
By putting all of this shit in a nutshell: The operator symbol summons slenderman, but he has to keep distance from it. It's effect may worn out but it'll do a nice defense for days/months depending on your luck and the material in wich you made the symbol. Also, he jams every gadged known to man, but he is unable to jam them all at the same time or even jam one every single time. I do not know if he jams the gadgets consciously or if it is a fallout of his presence. Also I do not know if he consciously goes to the operator symbol or if he just follows a smell or something like that for instinct.
Any help or data that you can provide will be appreciated.