A jump to/from 24-46 is out of spec according to the mfg. There's a reason for that, I'm sure, and it's not just to make more money in the service center.. (That's not a profit center for them) I learned the hard way that if I take care of my planes with the recommended maintanence, they tend to last longer!

The radio is a black box to me, and I don't even pretend to understand it.. But there might be more factors at play than just a simple range check with your TX... I dunno.. One scenario could be the poor tuning could could cause your RX to fail to reject somebody else's signal on another channel... Or combinations of channels.. This kind of stuff may not show up until it's too late. The point I'm trying to make is that you can't possibly range check under all conditions, and you may end up in a pickle, even if it seems to work today. Send it in and let them tune it. $30 tops with shipping, and it's cheap insurance. Retuning and a bench check isn't a bad idea to do annually anyway.

YMMV. Chuck