What's the difference between surface and aircraft radio systems? I'm interested in boats and surface vehicles, can't really afford new radio gear, so I would like to buy a used system, but aircraft systems seem to all that's available with more than 2 or 3 channels. Can those systems be converted for use with anything but planes or helos?

I'm not sure what the rules are in Canada. Here is a link to the Model Aeronautics Association of Canada
http://www.maac.ca/index.php

In the US, 75 mhz is for surface only and 72 mhz is for air only

You can get 8 and 9 channel transmitters on 75 mhz
Airtronics RD8000
http://www.hobbypeople.net/prdcls/r460762.asp
Futaba 9C Super
http://www3.towerhobbies.com/cgi-bin...I=LXRLN0**&P=0

There are probably others but it is late and I'm sleepy.

Thanks for the info. It's a good place to start; have to agree with the sleepy bit too.

The major reason for a seperate air only channel is because you can operate ground based vehicles anywhere and there are alot of them out there, if you lose control of a ground based vehicle the results are usually not as dangerous as losing an aircraft. We use an aircraft only frequency to prevent interference from anyone turning on an rc car in their back yard while we have an aircraft in the air. Remember that transmitter signal can effect an airplane up to 3 miles away.
My opinion, if you want to run a ground vehicle use a ground vehicle frequency or at the very least make sure no one is flying an airplane within 3 miles of you.
A friend of mine bought a Futaba 6EXA on 75Mhz for the same price as a 72Mhz for his tank.

Didn't 2.4 GHz start with surface models then later expand to airborne?

It's early now, and I've had some coffee.

Futaba also offers less expensive models on 75 mhz such as: the 4YF: http://www3.towerhobbies.com/cgi-bin...I=LXEFJ4**&P=7

I believe Polks Hobby sells their Tracker III on 75 MHZ, but for some reason I can't load the right page on their web site right now.

In the USA, you can also use the 27MHz units on surface or air, 2.4GHz on either surface or air and, if a HAM you can use 6 meteres on either air or ground units. I believe that 49 MHZ is legal on both but am not sure of that.

Many module radios from JR and Futaba can do either 72Mhz or 75Mhz (and maybe the ham frequeices, and recently 2.4Ghz) with just a change of module. One of the guys in my club uses the same Futaba 9(something) in his airplanes and boats by changing the module out.

Hey guys, thanks for all the information; I didn't know some transmitters could go as far as three miles, so I'll make sure that I stick to the assigned frequencies when I find something affordable. Special thanks to Piper Cub for the buying info. Being a newbie, I'm not too sure where to turn, so now I feel better equipped when I hit my local hooby shop.