The JR Sport receivers are "universal" in that they have a pos/neg shift jumper that you can switch if you want to use a different TX. I haven't tried it, though.

If you have the basic JR Sport S400 radio, and you are adding another plane to your fleet, you have a few options:

1. Buy a flight pack for $99 plus a $13 frequency crystal, and use your existing TX for both planes. You'll have to re-trim each time you fly, and make sure your servos are not reversed between planes.

2. Buy another complete S400 system, including TX, RX, battery & servos for $119. You can either order one on the same frequency you already have, or get another frequency so that you can be flexible if one of your channels is in use. (I did this on my second plane, got the same frequency on both radios).

3. Buy a JR Sport SX600 system for $159 and get a full system for your new plane, plus a computer radio that you can program for both planes. (I did this on my third plane)

Option 1 doesn't make a whole lot of sense, as the extra cost for another TX is pretty small. Option 2 works fine, but I am really liking the computer radio for a few dollars more.

There are a lot of other options if you go beyond the world of JR Sport radios, but that is the world I live in.