M5URR

I’ve been asked many times how I started studying antenna theory and antenna tuning. Well, in the old times there were just magazines, practical experience and experiments with friends.

Starting today, it’s much easier, but before starting your studies you need to focus on few points.

1. If you think that a tuner is changing or “tuning” an antenna, forget about this. When you tune a car, you change something in the engine CPU and you tune it. When you tune a piano, you change something in the chords and you tune it. When you tune an antenna, you do nothing to the antenna, so you are not changing anything. You are simply matching the impedance that the tuner sees at the entry point where the cable comes from the rig (Zi usually 50 ohm) with the impedance that the tuner sees at the exit point (Zo), which depends on the antenna used and the frequency. This video is very useful to understand the concept of standing waves. A lot of interesting information at this link by AD5GG
2. A resonant antenna is not necessary your best option if you want to use it on different bands
3. A low SWR is not necessary an optimal solution. Remember, that also a dummy load is usually giving great SWR results !!!
4. Many performing antenna shapes will never go even near to 50ohms!

Look at the links below

USEFUL TOOL TO CALCULATE SWR –>

A great source of training articles by ad7fo