The antenna lengh is not nearly as critical as many people think. If it where that critical, then it's position would also be critical, ie, in a striaght line. Also, if it was that important, you'd have to adjust the length for the different channels. Fact is, a Channel 12 RX and a Channel 60 RX have the same antenna length, even though there should be a few inches of difference. Heck, if you chopped off 2-3 inches, depending on your channel, you might have improved things . Most installations have the antenna bent around things a few inches here or there anyway.

Not only that, but some recievers can have up to half the antenna cut off with no reduction in rage at all. Specifically, FMA receivers are very non-sensitive to the antenna. I'm talking about duel conversion FM units here, btw. I think Futaba might be more sensitive to antenna length, though I'm not sure.

I have several antennas that have been dynamically shorted, one by quite a bit. Do a range check (engine off and running) and if it checks ok, you're good to go, regardless of the antenna length.

If you want to lengthen the antenna, it's not critical either, just go to radio shack and get some wire that is close, and solder it on there. I've seen planes with 4-5 splices of different kinds of wire in the antenna, and they worked just fine.

Oh, and fwiw, all my "work fine" is in combat matches. Combat is absolutly the worst envrionment for radios out there, if it works in combat, it will work while you are sport flying. We sometimes have 12 airplanes up at the same time, witht he pilots standing at random spacings, sometimes 3 or 4 guys nearly shoulder to shoulder. It's amazing what modern radio gear will tolerate, the stuff has gotten really good over the last few years.