I don't know if the 9C is the same as the Futaba 8U but futaba recomends that you have the first large section of your antenna extended for your range checks. It also recomends that you have at least that much extended anytime your radio is on for more than a few seconds or it will damage the radio. Here are two links to the Futaba web site Faq concerning your issues. They have a lot of good info.
fossil
http://www.futaba-rc.com/faq/faq-9c-q516.html
http://www.futabarc.com/faq/faq-q331.html