Cobra highgear hg75m mic squeals
get it away from the ext . speaker. They are cheap enough ,buy another one and see if it still squeals. If it does then you may have to jump the mic with resistors ,turn down your mic gain, check for talk back on rear where your pa. and external speaker hooks to inside the radio. If you see a resister connecting them then you have talk back . Mainly its a Keep the mic away from the speaker deal that makes them squeal. Try other cobra mics with the same pin out and see if it still happens . easy fix just have to be patient .