For A CMC, we wind the choke's toroid with coax as we are trying to impede the flow of current on the outer braid, but not the center conductor and therefore; keep excessive RF out of the shack. Am I correct?
You are correct. However you can make things more complicated and perhaps better by separating the wired in the "choke toriod." I have not done this. The Choke just is there to prevent RF from traveling down the shield of the coax back into the transmitter. I would think I would put the choke at the wall of the shack. I dont think that the snap on ferrites are good enough, I think you need a really big toroid that you can wind the coax around. (Hamfest time)
The actual "load" (antenna) is then the long wire and the shield of the coax before the choke. A Counterpoise makes the other half of the antenna (the part that is not the long wire) different and changes the impedance of the load, probably by a lot.
The transformer (the unun), transforms the signal into the antenna impedance. This impedance will be different for different freq. The idea is to get a transformer to get some sort of impedance that is workable on most bands. Length of wire is also important here.
I have an antenna tuner that I believe is meant for this sort of thing, it is a Sunair contraption that is automatic and meant for use with a specific tranceiver, the Sunair RT 9000. It is an enclosed watertight big box that is meant to go at the base of an antenna. There is memory involved and you can scan individual freq on several bands fairly rapidly. I believe that it was designed for shipboard use on steel ships where the Ground is the ship. Unfortunately for me the control connection is maybe 23 wire cable and I only have a 6 foot cable, not enough to put it outside.
I think the antenna they were using was not necessarily a long wire but some sort of multi freq antenna maybe something like a really big cone or eggbeater, or just multiple wires.
Here is an involved article illustrating the long wire and an Auto Tuner.
https://vk6ysf.com/longwire_antenna.htmWhether you have a counterpoise or not, if there is significant mismatch on the line between your tuner and your antenna, there will be RF feedback. I believe the idea here is to get the impedance in some reasonable range and use the choke to keep RF feedback to a minimum. I think the 9:1 is popular for this use.
Here is an advertisement that shows the basic idea of a long wire nicely:
https://palomar-engineers.com/tech-support/tech-topics/best-hf-end-fed-antennaThe counterpoise idea has a lot of different forms. Sometimes another long wire is used.
https://www.w8ji.com/long_wire_antenna.htmNote that a Balun (balanced to unbalanced) is used here not the Unun used with a counterpoise.
Interesting topic you introduced, Thanks.
Wally KC9INK