ORIGINAL: bruce88123
You can buy transmitters capable of multiple "model memories". This means that you can set a set of conditions (mixes and servo reverses and throw travel limits) for each of several different planes. It used to be that you would need a separate transmitter for each plane.
That said, unless your transmitter is capable of changing frequencies all of your airplane receivers will need to be on the same frequency.
And that's what's cool about the Polks systems, push a button attached to the receiver and it'll automatically adjust itself to a different frequency. I went a year and a half perfectly happy on Channel 58. Then along comes a new member (but long time flier). He also has 58 and it seems he's always at the field when I am. Not a big deal, he's a great guy, but it does introduce a conflict. I've encountered the same problem at the 1/2A fly ins that I attend, someone else on 58. Sure would be nice to be able to change channels (frequency) with a simple push of a couple buttons.