not hard to do chopper , You good with electronics ? can you use a soldering iron fairly well ? Can you follow the electronic dyagrams on the instructions and do the job correctly ? those are nice radios your talking about here , and if you don't have experiance with all of the above , FLNs' idea would be the safer way to go , they have good echo mic's out there from 20 to 80 dollars (you tend to get what you pay for) even though the DM-452 echo mic's are really rather decent at a 25.00 or so price tag.