bf1 easter egg

Hi, I started the easter egg on suez. I picked up a headphone and went to the mcom and recorded the morse code however my audio file was corrupt and therefore I don't know the location of my symbol. I have gone to all locations and not found a symbol. I tried getting a new headphone in hopes of starting again however i cannot find any headphones on all maps. When I go the mcom the color is black and no sound is emiited. What do i do now in order to finish the easter egg and get the dog tag?