u/Free-Database-9917

I am doing a skyblock world and haven't made it to the nether. I want to afk farm cobble but items despawn to quickly to leave a pile of pickaxes at my feet.

Is there a way to have a dropper drop a pickaxe once every ~3 minutes without having to use 500 repeaters?

An alternate solution I was thinking is with a 5 minute despawn timer, dropping 2 pickaxes (with like a ~30 second delay on the second) on a pressure plate when it isn't being pressed. I just can't figure out how to send 2 pulses off of a pressure plate being unpressed. Any ideas or alternate solutions?