I, along with thousands of other DX6i users, had managed to break the 2.4ghz antenna. The transmitter was in my backpack on a trip, and upon arriving home I found that the plastic was cracked at the hinge point. It was still usable, so I went on using it with a little black tape wrapped around it for support.
Recently, I had to contact Horizon's customer service about another issue, and I managed to get a new antenna at the same time. WARNING, if you own a DX6i, be careful peeling off the protective plastic stickers that are on all the switch name plates, and on the transmitters name sticker. Mine all peeled off just fine, except the left switch tags peeled the paint of with it. I called Horizon and was told that I would have to send the transmitter in to have get a new switch sticker. This seemed ridiculous to me so I emailed the Horizon Hobby Service Center Manager, and suddenly it was not a problem... The next day I was contacted by a Horizon Hobby employee who informed me that they were filling my order for the tag, and they went on to ask me to verify my shipping and payment. I was informed shipping and handling would be $9.99, and while I was on the phone I had an idea that it might be a good time to buy a new antenna. Upon asking if they had any in stock, I was told that they would throw one in for free! So, I basically paid for the antenna, got free shipping and the new sticker I was wanting... Once I got past the first line of customer service, Horizon did a great job of keeping me the customer happy.
Repairing the antenna is fairly straight forward, but their is a great how to over at http://www.chucknori.com that will make the process much smoother if you have any questions... Also, the antennas are now available online from different retailers ranging from $7.99 to $12.00. Happy fixing!