A redstone signal starts at strength 15 and drops by one for every block of dust it travels through. After 15 blocks it’s gone.
Steps
- Place a lever and dust
Run a line of dust away from a lever and watch it dim.
- Count to 15
The 16th block of dust stays dark.
- Add a repeater
A repeater boosts the signal back to full strength, so place one before the signal runs out.
Tip
Repeaters only send a signal one way. Check the little arrow on top.