I have a dumb question, will ask anyway.

I understand AM-FM (Audio modulation ....etc.I have a degree in elec., you think I'd know)
When it comes to RC model stuff, what is the difference? What is better?

I have a brand-new 4 channel AM Futaba in the box (use to do airplanes)
What is the legal? Will it work on a boat?
What is the range of each?
I never operate around other RC users, does it matter?

i would not use am in a gas boat only fm or 2.4ghz, am could get electrical noise and cause glitching. i belive fm has a longer range but im not 100% sure on that. want band are you on 27mhz and 75 mhz are for surface

Can an AM radio be used?
I understand the noise problem, I get that with FM too or is it worse?
What about range?
I need a simple answer, yes or no?

YES it can be used. NO it is not really recommended. YES it will be more sensitive to interference than the FM or PCM or DSM. Hope this helps. Range should not be an issue with either. Radios typically have way more range than we can use with boats.

I hate to disagree ... but AM "Amplitude Modulation" will go NUTZ with an ignition engine in close proximity. The RF scatter "Radio Frequency" caused by the high voltage secondary coil along with the RF caused by the jumping spark at plug just raises hell with what an AM receiver is looking at it terms of transmitter input.

DON'T use an AM radio in ANY R.C. application using a spark ignition engine


** Aircraft are used on 72mhz, Ground use vehicles use 75mhz or 27mhz frequencies.
Your OLD 72mhz radio by law ( The FCC ) is for AIRCRAFT USE ONLY

I agree, it might go nuts, but it can indeed work if precautions are used to make sure to limit interference sources in the boat. It has been done by many, although it is VERY rarely used anymore due to the low price of FM and DSM radios. That's why I said it is not recommended. Some things to do to eliminate sources of interference are: use a good resistor type spark plug, eliminate spark jumping by making sure your plug wire is good as well as proper grounding of ignition parts, often times it is preferred to also ground engine to stuffing tube, placing antenna as far away from ignition sources and metal objects in boat (such as tuned pipe) and keeping antenna at proper tuned length, NOT bringing into the radio box wires leading to ignition system (such as kill swithces), making sure the flywheel isn't scraping the coil... There is some good information on radios in the Ressources section:

www.modelgasboats.com/Resource...Tricks/Antenna/

www.modelgasboats.com/Resource...roubleshooting/ Scroll down, a lot of information on radios and electronics troubleshooting.

Thanks Scott
Catching up with my hobby, your comments make a ton of obvious sense.

I wish I had just bought a 2.4 ghz in the beginning. Ever since I got a 3 pk 2.4 ghz I have not had a single problem with glitches or range, even when the lawn mowers are around. Stay away from Spektrum in my opinion. I have been bitten before.