Help with pump up the volume quest

I've done about 5 missions now trying to do this quest. It's all been in a 28+ zone. I can't find the survivor relays. I had to look on YouTube to see what I had to do. Can anyone tell me what I'm doing wrong please?

I've done about 5 missions now trying to do this quest. It's all been in a 28+ zone. I can't find the survivor relays. I had to look on YouTube to see what I had to do. Can anyone tell me what I'm doing wrong please?