So you want to be a Radioactive Transforming Orangutan? Good, I'm guessing someone will post a guide for that too, but this is a guide for basic RTO=Radio Telephone Operator.
First of all you will be to know how to operate a LR, setting additional channels, etc. If you have no idea what I'm talking about, make sure to check out Badgers TFAR guide. Next thing you should worry about is the map, what are the objectives, using the terrain as your advantage, that also requires a bit more advanced knowledge of map reading. I shall repeat myself if you are imagining a map as a delicacy in some country far far away, you should recheck yourself and check out the Map reading guide by Badger.
Now, since we covered the entry qualifications, we move on to what does an RTO do. RTO is in charge of the vehicles and mortar. You will be operating with them using LR freq. 67
For vehicles it is highly recommended that you know what kind of vehicles are used, what's their level of armor and level of destructiveness. Same goes for the enemy vehicles. So using that knowledge plus the map and the current objectives. You will be expected to relay messages from the PltHQ Leader, to help out infantry if they are pinned and so on, aswell as giving them some movement instructions (infantry is clearing a town, vehicle is moving parallel outside of town). Mostly in our missions, the vic commander makes those choices and on that I shall finish the vehicle part.
For mortar, during briefing, give a suggestion for a mortar locations that has almost the same altitude as the mission objectives do, it will make their lives a lot easier and the shots a lot more precise. The effective range is 3 kilometers and the ammo crates have 32xHE, 32xIllumination and 32xSmoke rounds. Always and always, you should be able to see the target and let the mortar know was the shot effective.
Radio comms should sound something like this:
RTO: RTO to MORTAR
RTO: Requesting fire mission at marker X-1, 3xHE.
RTO: Correct. Send first and wait for corrections.
MRTR: First splash sent ETA 25sec
RTO: Good effect on target, continue with fire mission.
MRTR: Fire mission complete, last round ETA 25 sec.
RTO: Target is neutralised.