One VERY important point to note... Do NOT allow your ELT to be activated for 50 seconds or more. During the first 50 seconds the ELT is in warm-up/self-test mode and the signal it is broadcasting is flagged as being invalid. Once you cross the 50 second mark, you will be transmitting a valid distress signal and it won't be long before the search activities begin.
Again, 50 seconds is the magic number. Best not to let any ELT test go on longer than the bare minimum necessary to ensure completion of the self-test sequence, generally 10 seconds or less.