Jump back through the window and get out of the museum. Now you can head out to find the first disruptor, using the information displayed on-screen. The object you're looking for has been placed on a balcony n the northern part of the museum #1 #2.
It of course would be good to attack the enemies below by surprise. The difficulty in this fight is that enemies might try to take firearms from the nearby locker #1. You need to stop them at once then they try to. If one of them manages to get one, start dodging and try to quickly disarm him. Afterwards approach the disruptor and approach one of the screens #2. Press A to break through it and tear out the wires.
You have to do the same with the two other screen of the disruptor. #1. It will disable the machine and let you head out to find the two others #2.
The second disruptor can be found on the roof of one of the nearby buildings #1 #2. Getting onto the ledge of the nearby Gotham Bank building would create a good starting point.
Note that the enemies are equipped with firearms, so an all-out attack isn't a good idea. Silent takedowns also aren't great here (except for the first one), as the Thugs here are also equipped with transmitters notifying of them getting eliminated. I'd suggest taking out single enemies #1 by using the glide kick (and quickly finishing them off afterwards) #2 and quickly leaving the site once you're done.
If you want to be sure you will be able to safely evacuate after each attack, you can consider using the smoke pellets #1, though you could also just use the Grapnel Gun to quickly return onto vantage points #2 or the roofs of the nearby buildings.
Keep repeating this until all the enemies guarding the second jammer are eliminated. Land nearby the mission objective and destroy the machine in the already known way #1. Listen to the next radio conversation #2 from which you will learn that the last, third jammer, has been placed underneath Arkham, at a closed subway station to be precise.