Antenna Theory - What's Happening
Antenna Theory – A small bit, anyway It is an early Sunday evening, and you have been in the shack for over an hour. You have been tuning the HF bands on your new Icom 7300 transceiver. Linked to the 40-meter half-wave dipole that stretches from the far yard tree to the house eave, you are experiencing noiseless, 1.2 SWR transmissions and picking up DX stations in South America and the Pacific rim. Your wife calling you to dinner quickly snaps you out of your Tuesday, after work nap. It's time to get up from the Lazy-Boy lounge chair. While at the dinner table, you reflect on the dream that you just had. It was all a fantasy; you get no such performance from your ham shack setup. You know it is not good, but you don’t know why. It's time to dig into what may be happening. Radiation occurs when electric charges accelerate. Constant-velocity current does not radiate; time-varying current does. In a half-wave dipole, the RF source forces electrons to speed up, slow dow...