To begin finding the signal jammers, find the building with the video uplink in New Venice North. Defeat the Drones, Athena mercs, and the Alpha drone. Contact Gabril on the console in the building in the center of the area and agree to help him destroy the jammers. The jammers can now be found at the following locations.
Destroy the two wooden doors with the SCAR gun in Gabril's building. Look to the left as you go through the second door to see the jammer up on the cliff. You can destroy it with one canister from the SCAR. Note: You can also find a bounty card farther down the walkway.
As you leave Gabril's building through the automatic door, look on top of a building to your right to find the second jammer, colored gold by the sun. Use the SCAR gun to destroy it.
Return to the Village Square where you killed the first Alpha Drone. Just after you duck under the destroyed gate, look up at the cliff in front of you to find the third jammer. It is on the right side of the cliff in front of some trees. Destroy it with the SCAR.
Return to the first area of New Venice where you met Pavlo and retrieved the SCAR. Go to the area where the Supply Depot is located. Go down to the Supply Depot building. When facing directly at the building, look to the left to find the fourth jammer on the cliff, next to a crane-like device.
Stand outside the dead old man's house and turn to the right. Walk forward and climb up the ladder on the left to access the town's higher level. Walk forward to the first intersection. If you are at the correct location, you should be able to see a building with a large red "Akkor" logo painted at the top on your left. Turn right at the intersection and walk up the path to the end.
Have the stairs leading down to your left, to look slightly to the right to find the jammer.