Like many people I can be quick to criticize and sometimes slow to praise BUT I want praise Coiltek. I want to thank Trevor Ferraresso at Coiltek in Phoenix, Az for really great service. Thanks also to Bart of Big Boys Hobbies for the referral to him. I had the 6" Digger coil for a couple of months and was never happy with the performance. As time went on it became even more unstable and impossible to ground balance. I finally called Bart and subsequently sent the coil back to Coiltek in Phoenix. I sent it UPS ground on a Monday and received a brand new coil on the following Thursday, just 10 days later and it took 5 days to get there. You can't ask for better service. Thanks guys, great job. I tried it out in my back yard and it works great.