Would you please answer the 2 questions you pose so that someone , not as knowledgeable as you (that would be me), can learn something form this? I am guessing the answer is "impedance", but not sure. Thanks in advance.Oh? What's the purpose of that RG-58A/U section in there? Any particular reason why RG-58A/U was chosen, and the significance of it's length? "Tuned" doesn't necessarily pertain just to frequency.