Maverick:

Some countries are very picky about what channels are used by what. In North America, getting caught using a unit out of its proper designated usage-band can cost you a fine, loss of the equipment, or even jail time. Most clubs won't let you run 'officially' unless your radio rig is legal, as the club becomes responsible for the regs in that situation, and they don't want to eat the fine.

The fliers are ~very~ respectful of this, and unless you have an aircraft-band unit, and a dual-conversion unit at that, you are NOT allowed to fly, as their insurance only covers them under those circumstances...

But more to a point: is the FF-9 a PCM radio? If it is, it won't work with the Tamiya DMD units. The guys over here have tried, and no-one that I know of has suceeded in getting a PCM unit to work with a DMD unit. Heck, Tamiya even wrote the instructions as if all users would use a Japanese-use SkySport 4 radio, so the mode setup is a bit wierd (they transpose channels 1 & 4 - its a flier thing... the air-radios usually have a switch)

Bottom line is... do you want to risk running afoul of the authorities, or some guy that comes after ya cause his expensive plane (or helicopter) crashed when you tried to use your tank, and locked his plane up (usually called a 'shoot-down' situation) ? Or your tank goes wild and gets trashed cause some flyer turns on his unit? Think about that before you decide...

WhiteWolf.

Additional: Your FF-9 seems to be called a 9C here. It claims to be FM & PCM operable... so you'll want to run it in FM mode, with an FM Rx so it will work with the DMD/. I've never had a PCM unit, so the 'how-to' of switching is out of my league... sorry.