Jose wrote:
GPS on and booted up, etc. Tune up 121.5 on your comm and hold down
the PTT for 20 seconds, no need to say anything.


Don't forget to make appropriate arrangements and do this in an
appropriate time frame. I think it's five minutes before the hour for
testing, but I'm not sure. Look it up before you actually do it.



You're thinking of ELT tests. There is no defined test period for this.