I buy cheap Bells at Walmart.
Just the bell, nothing attached to it.
Ones I prefer are probably closer to 3/4″ diameter. 50/$2
Use small zip tie.
Zip tie the bell to the rod, I like to be 3 or 4 eyelets from the tip. Bell should be attached firmly to the rod. Clip tag end of tie. Put bell on bottom of rod to never interfere with line. Zip tie through eyelet legs.
With rod in rod holder, you should be able to lightly tap the butt and sound the bell. Wind waves and boat rocking should NoT sound the bell.
There ya go. Been through many revisions and I’m happy happy happy with my bell setup. No false alarms and if something bumps the bait it’ll sound.
Bell sounds, before removing from rod holder tighten the line up. If rod tip continues to bend, keep slow cranking until rod loads, then remove rod from holder and fight that fish.
The above has been proven time and time again!!!