I have some questions I am hoping someone is willing to help me out with as I am quite confused

This is what I want to do: I want to purchase an ARF EasyStar, and I want to use a 4 channel radio for it, the reason being I can use the radio in the future for an upgraded plane, but then I am wondering what servos and receiver i will need for the transmitter, and will the servos and receiver work on the EasyStar? So my questions are as follows:

1. If we are building an ARF plane such as an easystar or a great planes pt, and we supply our own transmitter, reciever servos etc...., my first question is this, Are there specific servos, receiver, and/or ESC's that only work for the type of transmitter we get? Or can we purchase any servos, receiver etc.... for the transmitter? I ask because I may want to purchase a 4 channel transmitter from a friend but he has no servos, receiver or any electronics I would need for the plane so I need to find out exactly what I need to make the radio work.


2. I'm confused on what the difference is between an Electric Speed Contol (ESC) and a servos. How do we know if we need both, or just one, or neither etc...? I always thought esc's are only used on rc cars/trucks but apparently we need them for airplanes to. I thought the throttle on the transmitter controls the speed of the plane and the servos & receiver is what tells the prop how fast it goes. So how does an ESC come into the picture? Why would we need both ESC and Servos? I don't get it.

3. In trying to select a transmitter I can use in the future, by budget is very limited so I cannot invest much into it. But, I have seen many used ones (including what is being sold on this website), and I am wondering what the best brands are. Also, I have seen many 4 channel AM transmitters. they seem to sell much cheaper then the common FM. I realize FM is better, but if I purchase an AM, how will that effect my flight performance? If there is nothing wrong with AM, what is recommended in a 4 or 6 channel system? Are servos and receivers readily available for AM radios? Or, do you recommend me just sticking with FM even though they are more expensive? Is there really that much of a performance difference between the two?

4. What channels does a 27mhz FM transmitter have? Is a 72MHZ better then a 27MHZ FM transmitter? I ask this only if you recommend me staying with the FM frequency

5. Do we need one servo per function on an airplane? So, it goes like this: Prop-1 servo, Rudder- 1 servo, ailerons- 2 servos (1 for each wing)? , and any misc servos for extra functions.....such as xport or combat, or night flight etc... Correct? So then, where does the ESC fit into the picture if we already have a servo for the prop? Do we not need it?

6. On transmitters, if we want to change a channel, do we do this by adding a different crystal to both the transmitter and receiver? Or is there a different way of doing this? Also, are all crystals the same size? Or are there special sizes etc... only for specific transmitters/receivers? What is the exact function of a crystal- is it to set the transmitter/receiver at a specific channel, or does it act as a fuse of some sort also? Does the number on a crystal (example: 2 TX Band) represent the channel it is on?

Well, I think if I can get these questions answered, I'll be able to sleep better at night

Thank you very much for all your help. I realize its a lot of questions, but soon I will know all this

Feel free to PM me as well. Thank you.