Making wireless railway controller

Hello,
I would like to build a controller for a model railway.
It just needs to be very simple, as the plan is to run up to 3 locos on a 00 gauge shunting plank of 4ft * 2ft. The is already information on this site of how to set up the locos to receive the signals, but i do not know how to build the controller.
The main reason for doing this is to run the railway without any power to the rails (the power being supplied by a rechargeable battery fitted inside the loco. Now i must admit that i am 70 years old and only have a very few brain cells left. If someone could supply a list of the parts i would need to buy to make the controller i would be very grateful. If you envisage a standard analogue Hornby controller this is all i am trying to re-produce but wireless with no direct electrical current to the rails.
If you can help thank you very much in advance. If this is not considered "appropriate" please ignore
GreenBR

Please post a link to what you have found

This has come up in various forms before. In particular, Robin2 has posted about a similar setup he worked on. It's mentioned In this thread but I seem to recall that there are plenty of others.

Well after reading anything i can find i am struggling. there are some ready made products out there. just pay your money and away you go, but where is the fun in that! Robin2 has documented the reciever for the dead track and this is the way i intend to go (whoever you are Robin2 thank you very much for putting it out there so to speak). I tend to get the feelling that the little controller that is fine for me is deamed a bit simple for the average guy, and is passing everyone by (in other words not worth the effort to make) I hope this is not true.
I have purchased a box of bits from china with samples and code a bit like a chemestry set would have been in my day and will have a play with that to start. Thankyou all who replied and read my post, this is where the adventrue begins