Foundations Of Amateur Radio

Foundations of Amateur Radio When you use your trusty multi-meter to measure resistance across a 50 Ohm resistor, it shows 50 Ohm, but when you use it across a piece of 50 Ohm coax, you see either infinity, or 0. Similarly, when you measure across a folded-dipole, you see 0, not 300 Ohm. Does this mean that a 50 Ohm resistor is somehow different than a 50 Ohm piece of coax and why is the feed-point impedance of a folded dipole 300 Ohm, when your multi-meter clearly says it's 0? Does this mean that there are two types of Ohm? Today I'm going to explain why this is and what's going on. Yesterday I started reading up on the subject and every single explanation I came across went into deep ju-ju with scary maths, using complex and imaginary numbers. I did a bit of that in my dark past, but none of that is needed to understand what's happening. As you know, there is such a thing as Direct Current or DC - we use it with batteries and little power supplies, in simple circuits and all manner of day-to-day activiti