Great post Homer.
Happened to be unavailable since the "counterpoise" subject arose in this thread.
I to, since the aforementioned thread, have been actively seeking out information on this term as used in antennas. I have learned a lot on the subject in my search for reliable information, which is hard to come by. Also, not all of what I have learned is directly related to the term.
I started a thread in another forum on this topic, namely what it was and what source they had for their information. One person (ironically the first person) listed a source, wikipedia. Several others chimed in, they all had their own different ideas, but no one could tell me why, or give me any sources short of some ham's call sign that I have not seen or heard of before used the term in such a way. I had what, five more unique descriptions for what the word meant.
It was about that time that I realized that there is no real need for the word today when referring to antennas. From its original use as a "capacitive ground", to one of the many current uses including when it is often misused to replace the term "ground plane", there is no use (legitimate or otherwise) of the word that doesn't have another word or phrase that more accurately describes what is being referred to at the time. All it does is spread confusion, and it always will as long as it has different meanings to different people.
Perhaps one day the use of the word will congeal into a new unified (or near unified) use of the term, somehow I doubt it. Perhaps it is best to use whatever other term or phrase describes what is being talked about and let the word counterpoise, when referring to antennas, die.
If you want to do research on the topic, Laports book, Radio Antenna Engineering, which was one of several books referred to and quoted by Cebik, is a good source and available in .pdf format online for free. I personally prefer the description given in the 3'rd and 4'th (they are the same word for word) edition of the ARRL Antenna Books, which is much more readable for the non-engineer, but harder to find. These two sources don't agree exactly, and that is common among the few sources from the 40's and 50's that talk about the term "counterpoise" that I have been able to locate. While they do have their differences, so far they are all referring to a "capacitive ground" when using the term "counterpoise". For example, some say the radials (or wires) should be resonant while others say that you should use cross connected wires in a spider web pattern to prevent resonance. Still others don't even mention resonance. I guess even then there were differences in the use of the term, although not as drastic as some of the differences today.
If your looking for a good analogy of how the traditional meaning of the term "counterpoise" works, look at a magnet mount on a car. The magnet and the metal on the car near the magnet forms two plates of a capacitor. A capacitor will let AC current (such as we see with our transmitted RF signal) pass from one side to the other, in the case of a magnet mount antenna creating a connection with the body of the vehicle it is sitting on. The bigger the magnet (to a point) the more efficient it becomes. The radials or, as presented in Laport's book as well as others, the spiderweb layout of elevated wires and the earth below perform the same function as the magnet mount and the body of the car. As you raise the elevated radials/spider web layout of wires further above ground the larger they need to be to maintain the same capacitance with the earth ground below. The heights where a system is effective depend partially on the frequency the antenna is using. To high and it looses its capacitance all together and becomes an artificial ground plane as it tries to replace the earth below instead of providing a connection to it.
The DB
