FROM
EARTH TO AERIAL
What's going on?
There seems to be a hell of a lot of confusion about SWR, RF current, ATUs, aerial length, RF earth systems, burying miles of expensive copper wire as some sort of tax-loss scam, ground rods, twin-feeder, coax... Many of the explanations concerning such things that I've heard on the amateur bands only add to the confusion. Talk about the blind leading the blind. I'm no expert. In fact, aerials dwell in a complex field of their own. However, I hope to dispel some of the myths that have sprung up over the years. The other day I heard an M3 asking a G3 about indoor HF aerials. The G3 suggested an eighty metre dipole slung around the room using the picture rail for support. Yeah, right!
Aerials are in a field of their own. There's the horizontal half wave dipole, end fed wire, grounded Marconi, quarter wave vertical, Zepp or Zeppelin, carolina windom, multi band antenna, loaded wires and elements, the trapped aerial, directors and reflectors... Then we have RF ground current, losses, impedance matching, the ATU, loading coils, resistive and inductive stuff... Blimey, there's a lot to it!
To many old timers, my pages on aerials and earth systems will be kids’ stuff. Many new-comers to the hobby will wonder why I’ve used the analogy of the current flowing in a battery and bulb circuit when talking about current flow in an aerial. On the other hand, there will be old and young who are not so knowledgeable and eager to learn. Hopefully, they will find my ramblings useful and informative.
We all had to start somewhere, and I find some of the old timers’ comments on the bands about M3s not only sad but downright rude. One M3 joined a group of amateurs on a certain band and was ridiculed. He was making his first contacts with his new license. He was only running ten watts, but was virtually called a liar because he was such a strong signal throughout the UK. The old boys then went on to try to confuse him with peak envelope power etc. The M3 finally closed down.
So don’t laugh because some of the information on the following pages is kids’ stuff. And remember that M3s are no less amateurs than G2s. All they lack is experience. Even the oldest and most experienced amateurs started somewhere. Probably by hooking up a battery and bulb on the bedroom floor.