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Blog - Ground-plane antenna project

The wonderful thing about ham radio is, no matter what part draws you in, there is an equal and completely opposite part that will make you shy away. Ham is an equal opportunity hobby. There’s plenty of rewards and challenges for everyone!

Some hams are drawn to the technology and electronics side of the hobby and shy away from on-air interactions. Others, once over the mic fright, enjoy the one-on-one and shy away from electronics.

If you’ve read much of the blog series, you know I am a big proponent of challenging yourself. If you seek out what you aren’t instantly drawn to and become familiar with it, it teaches you confidence.

For many women, electrical components, antenna builds and soldering represents part of the hobby we are not instantly drawn to. For good reason. Most men have been exposed to electronics, automotive repair and woodworking their whole life. Most women have not. It’s an exposure issue, but it’s not something we should shy away from.

Last week Hedge, AE5FZ, presented the technical topic using an antenna he built in less than 15 minutes. This is a fun, simple little project anyone can build. While there is less than $2 worth of materials involved in this project, the lessons learned are invaluable.

Before you run for the hills ladies… stop, take a breath and look me in the eye. You can do this. It’s fun and painless! Well, as long as you don’t rest your hand on the soldering iron, it’s painless. (Nope, not making fun of you KC5MGY, I swear.) Other than that, I stick by my original comment. Fun and painless.

Full instructions can be found here.

www.hamuniverse.com/2metergp.html

If you try this project… Wait, let me correct that… WHEN you try this project, you are going to learn a tremendous amount of useful ham-type geeky information that you really *did* need to know. You just didn’t *know* you needed to know it.

Things like:

LEARN THE BASIC SUPPLIES NECESSARY FOR AN ANTENNA BUILD. Like for instance, you will discover chassis mount SO239s don’t normally hang around in the typical ham-shack. We found them at Fry’s in Arlington, but you can also order them on-line.

After that, everything else is available from Home Depot or the local craft store. There’s a choice in wire material, as well. You can use copper for the elements, but you can also use brass. Brass is slightly less conductive than copper, but it’s harder. This will make bending more of a challenge, but the finished project will be sturdier. Also, regarding wire gauge, the smaller the number the thicker the wire. This project calls for 12 gauge wire, but you could use 10 or 8 in its place. Thicker wire will also give you wider band width.

LEARN THE BASICS OF GROUND PLANE REFLECTANCE. Ground planes radials serve as a horizontal conducting surface for your antenna. They reflect radio waves from the other antenna elements and make your antenna receive better. The wave length of the radials should match the wave length of the main vertical element. In other words, if you’re building a half-wave antenna, your main element and your radials should both be half-wave.

LEARN TO CALCULATE THE LENGTH OF ANTENNA ELEMENTS BASED ON FREQUENCY. Like the old “There’s an ap for that!” saying…in the ham world, it’s a guarantee …. “There’s a formula for that!” As I am not a math nerd, I’m not even going to attempt to give you the formula, though it appears to be simple. If you’re curious, look it up. My preference is to pop “antenna length calculator” into the Googlator. You will be rewarded with a plethora of websites willing to make your life way easier. Just plug the frequency in and voila’, it gives you the length to cut your antenna elements.

Speaking of frequencies, you can build this antenna to fit any frequency. But remember, if you customize for a repeater frequency, be sure to build it for the input frequency. (The one that shows up when the push-to-talk is engaged.)

LEARN THE BASICS OF SOLDERING. This includes what supplies you need to solder. Also pretty simple. You need solder, flux, and a way to melt said solder -- a soldering gun or wand. There are applications for both, but that’s an entirely different topic. For now, just know – for this project, either will work. A piece of sandpaper to rough up the surface of the main element before soldering would also be useful.

LEARN HOW TO USE AN SWR METER. Most of us have a clue what to do with an SWR meter, but may not have actually used one. (I haven’t.) Be aware, your meter needs to match your bandwidth. (Two meter SWR meter to measure 2-meter frequency.) With an SWR / watt meter, you must transmit in order to take a reading. An antenna analyzer, aka the Cadillac version of an SWR meter, doesn’t require the transmission in order to take a reading.

And last, but surely not least…

LEARN THE METHODS OF TUNING AN ANTENNA. I learned a hard lesson when I installed my mobile antenna. ALL ANTENNAS NEED TUNING. In the case of mobile antennas, this means raising or lowering the antenna to get the proper length for best reception. For this project, there are three different ways to adjust the antenna so that it receives to its fullest capabilities. You can bend the radials downward. You can adjust the length of the radials by clipping off 1/8” of wire at a time. Or you can adjust by clipping the vertical element 1/8” at a time. Each time you adjust, take a new SWR reading until you have received as close to 1:1 as you deem possible.

I’ll be honest, I haven’t tried this project yet, I’m waiting on my so239. But I will try it, if for nothing more than the pleasure of doing it. Like I said, lots of learning opportunities in this simple, simple little project.

Plus…

You never know until you try something. You may be really good at it. There’s no reason why lack of exposure should inhibit you. Who knows? You may be a soldering guru. Might as well try it and find out. In fact, try it a few times. The fun is in the process.

For more projects, Googlate “coat hanger antenna ideas” and see what you come up with. And thanks very much to Hedge for sharing this one with us. Happy soldering!

73 Y'all!
KG5BHY