Smith chart

Although the Smith Chart looks quite scary at first it really is not.

The smith chart will tell you a great deal about antennas and resonate circuitry.

A fellow ham gave a simplistic explanation of the area of a Smith chart which I wrote up for amy club news letter (a portion of which is attached):

Visualize the CIRCLE area of a Smith chart as a pond and PIFTY-OHM, the fish is swimming there exactly in the MIDDLE. He is facing toward the right side of the pond, which is the OPEN sea. He has a very SHORT tail on the left side, COILy hair on TOP and unfortunately his CAP fell off and sank to the BOTTOM.

So in other words the center horizontal line is pure resistance, 0 ohms on the left, (typically) 50 ohm point in the center and open (Infinite) on the right. Inductance characteristics are on the top half and capacitance characteristics are on the bottom half.

Check out this SMITH chart program and try creating a few solutions with the building blocks:
http://www.fritz.dellsperger.net/

This program has been a lifesaver for me and even though the free version is limited to a few components it has done everything I needed for some rather complex setups.

Also check out the SARK110; a very handy and relatively inexpensive (antenna/polar/smith/transmission line tester/ETC) analyzer for circuitry under 200 MHZ.

John

Hello,

+1 with davorin 🙂