Yes,

In most cases you can. BUT there are some exceptions.

BTW, I recommend the DX7. I know at least 6 Giant scale 3D guys, (names many of you would know), who are flying GS planes, including comp-arf's on this system. The risk of a shoot-down is too much for many of us with expensive planes. The use of 72MHZ and frequency boards will likely disappear in just a few years.