Learn by Doing Smith Charts

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Where Have We at Chelsea Been

The Chelsea Amateur Radio Club (CARC) began sponsoring license upgrade training using the Smith Chart as the operational vehicle. Wes Cardone (N8QM) has been presenting a series of lessons centered around the Smith Chart with the premise that the student already knew a lot about electromagnetics relating to the Smith Chart but just didn’t know that he or she knew it. But it was all academic lecture with no labs.

Where Has Wes Been

Wes began to think to himself about how he learned electronics. It started in the Air Force, continued with correspondence study with the National Radio Institute (NRI), and then finally electrical engineering studies at the California Polytechnic State University at San Luis Obispo, California. All of that was lecture mixed with labs. Yes, even including the correspondence studies through the NRI. Looking at today’s Cal Poly website, we can see that its moto today is the same as it was in Wes’ day: LEARN BY DOING.

What Should We Do

So, what might be a good course of action for us at the Chelsea Amateur Radio Club? Learn-by-doing is fine when you have mega-donors behind you. In the Air Force there were unlimited funds in the days of Viet Nam for oscilloscopes and lab equipment. Likewise at Cal Poly, very elaborate lab equipment was found, well stocked and well maintained. But in amateur radio, we are on our own. Each one of us needs to come up with the funds to acquire appropriate lab equipment to suit our training goals. Long-term we could look to the ARRL for funding aid. But what about right now?

Miniaturization to the Rescue

Many of us have heard of or acquired the magnificent nanoVNA. A couple of years ago, Wes gave a presentation to the Chelsea club on the nanoVNA even going so far as to call it “God’s Gift to Amateur Radio.” Wes also gave that same presentation to the Jackson Amateurs (W8JXN Cascades Amateur Radio Society) and wrote up a couple of blog posts(1) and blog posts(2) on it.

The nanoVNA can serve as a very nice lab instrument for a select series of laboratory studies. But we are still left with having students jig up electrical components, working with dykes and pliers, and just a bunch of things that, while not objectionable, complicate things.

Enter the RF Smith Chart Demo Board

While mini-connectors are fragile, this miniaturization brings technical education to the masses.

The board in the above illustration is designed for RF training in basic electronics together with the Smith Chart. These boards come shipped with two compatible connectors having SMA connectors on one end and on the other end they have the miniature and delicate IPEX connectors used in cell phones and other mini pieces of equipment. These demo boards cost from about $20 to $40 each. The connectors soldered to the board are connectors that you have never seen before because they are typically hidden or covered over within the equipment where they are used. They are too delicate to have people messing around with them.

But be advised about those nasty IPEX connectors: They are fragile when subjected to ordinary handling. In the CARC Smith Chart Tuesday training sessions we will be covering techniques and recommended tools to attach and de-tach these connectors with ease and dependability. Bring an everyday cheap pocket knife to easily detatch these connectors.

You don’t have to buy anything right now. Here is a page where I have gone over many details in case you want to buy right now. In the next few Tuesday night sessions, Wes will demonstrate the use of these things and advise on where and how to buy.

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