November 19, 2023
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Hello ECR Family, and welcome to The Antenna Farm. This is your friendly Antenna Farmer Charles, KC6UFM.
In this installment, we’ll talk about some of the tools you will need if you want to build—and design—antennas.
Before we get into the actual nitty gritty of tools, let’s review why you might need these things…
Antennas are one of the few areas of Ham Radio left where you can build your own gear, usually called “Home Brew” by most Hams. Building any kind of transmitter beyond a simple CW unit is out of reach of most people. It often requires highly specialized tools and skills and, honestly, is not even close to cost effective. Building a few “accessories” for the shack is possible in many cases, but usually these accessories are more of a convenience than something that will actually make your station better.
But antennas…pretty much anyone who can handle common hand tools, read a tape measure/ruler, and follow directions can build some very good antennas that will enhance their station.
When I first started getting interested in antennas, my Elmer told me to think about building an antenna from plans just like I was in the kitchen cooking. The recipe has all the details worked out and all I needed to do was follow the recipe. Of course, as my Elmer knew, that would lead me to make changes and try new things, just like cooking. One day I’ll tell you about my “Dual Feed Quad” design. It didn’t end well.
The main objection I hear from Hams about building an antenna goes something like, “I don’t know anything about how they work! I can’t build it if I don’t understand it!” In a word, bull. First of all, you have The Antenna Farm articles to give you some of the information needed to learn what’s going on. Second, remember that YouTube is your friend…there are many videos on building a wide range of antennas. Third, the Internet in general is full of plans, calculators, white papers, and more. Fourth, look to your Antenna Elmer for help, or find an Antenna Elmer you can ask for help. Lastly, there are many great books out there, and the main ones are “The ARRL Handbook” and “The ARRL Antenna Book.” Yes…those two books will set you back about $100 new, but you can often find used ones at ham fests, flea markets, and swap meets, and many Ham Radio clubs have loaner copies. Also check with your local library.
To keep things organized, I’m going to break down the tools you need into several categories.
But, there are two items I want to mention right up front…
1) A good pair of safety glasses and, optionally, a face shield. No…a face shield is NOT a substitute for safety glasses.
2) A pair of decent mechanic’s gloves. In some cases, you may also need “rubber” gloves when working with solvents and/or glues.
Remember…safety first! Well, top five anyway.
Hand Tools
For most projects, this list is fairly small and simple. Things like an assortment of screwdrivers, wrenches, Allen keys (preferably with a ball driver on one end), and pliers are a must. Other things like an assortment of clamps (C , strap, and bar type as well as pinch type), levels (including a post leveler for masts), and corner clamps will be very handy. Get a few tape measures and a combination square with a twelve inch scale. One thing I have found that I can’t live without now is a cheap (~$10) “Composite Digital Caliper” from Harbor Freight. You will also need a good assortment of drill bits, and I would suggest getting both a set of “Number” and “Letter” bits plus a few fractional sizes. You don’t need to go out and buy Snap-On tools…the Harbor Freight specials will more than do the trick.
A few “specialty” hand tools are also needed…Things like wire strippers for wires from about #22 to #4 AWG in both stranded and solid wire (yes, a #14 solid wire and a #14 stranded wire need different strippers, and do NOT get “automatic” strippers! They WILL damage the wire!), crimpers for terminals (works for ring, spade, quick, etc.), coax strippers for RG8 and RG58 family coax (NEVER strip coax with a knife!), coax connector crimpers for RG8 and RG58 cable (these usually come with one crimper and two sets of jaws), and a cable cutter will make things much easier. For all of these items, don’t go for the cheapest thing you can find. In fact, look at the higher end tools. Odds are, for example, if you pay less than about $45 for a coax connector crimper, it will likely never work quite right. For wire strippers, look at either Ideal or Klein brand. These specialty tool are NOT the place to try to save money.
Power Tools
A cordless drill is almost a must. Fighting with a cord while trying to drill a hole in the middle of a large antenna is a nightmare. Odds are a 3/8” drill will be just fine, but a 1/2” might be needed in some cases. Nothing fancy needed here.
A Dremel type tool and an assortment of bits, cutting disks, burrs, and such is a great help. Again, a cordless unit can be had at Harbor Freight for about $25 or so.
Soldering irons are another thing you’ll need. At a minimum, get 25w and 50w pencil irons AND a good quality soldering gun of at least 250w. Personally, I will only buy Weller brand irons and guns. Yes, they are expensive, but they work 100% of the time and seem never to wear out. To go with the irons, you’ll need a tip cleaner, a wiping sponge, a few extra tips, some soldering paste (rosin based) with brushes, and some solder. Yeah, solder…today you can still buy tin/lead solder if you look for it, and you can also get “lead free” solder. There is no doubt that lead, in ANY amount, is not good for you. There is also no doubt that lead free solder, particularly in antenna work, does not work very well because it is brittle and will crack with time. It’s your call which to use. No matter which you get, be SURE it is rosin core. NEVER EVER use acid core solder for electronics or antennas.
By the way…on the soldering tools, be sure and follow the warning label, especially the warning not to put the iron in your mouth.
Another power tool that is very handy is a jigsaw. Some people know these as saber saws. And don’t forget an assortment of blades for both ferrous (steel) and nonferrous (aluminum) metals and wood. While handy, a hacksaw will probably get the job done with a little elbow grease added. When picking out your metal blades, remember that most of the metal you will be cutting will be fairly thin, so get blades with a fairly fine tooth pattern (24 or so should be fine, but 32 is often better). If you’re going to work with HF antennas, a “Sawzall” type reciprocating saw might be a good addition.
Test Equipment
Sadly, you’ll likely spend more in this category that in all the others combined.
You will need at an absolute minimum an SWR meter. SWR meters are frequency sensitive, and you will commonly see 1-54 MHz all lumped together, but in the VHF/UHF world, you may have to buy separate 2m, 1.25m, and 70cm meters. If you look around, you can find meters that will cover 2m up through 33cm or higher. Check flea markets, swap meets, thrift stores, and the like for deals. Even brand new, an HF SWR meter shouldn’t be more than $75.
A much better option is either an Antenna Analyzer or VNA. These are far more accurate and flexible than an SWR meter, but they are more expensive and have a learning curve. The price range here is around $50 up to over $2000, so your budget may dictate what happens here.
An oscilloscope is also a good addition, but we’re looking at another expensive piece of equipment that has a bit of a learning curve. The scope can, however, do things that nothing else can do. Oh, and don’t forget the correct RF probes for the frequency band you will be using. There are a few small, portable scopes that, while not vert accurate, will do the job available in the $200-$300 range.
A multi-meter is another must. I prefer the digital units over the far more accurate analog meters. Yes, analog is about 500 times more accurate than digital, but analog is harder to read. The good news is that you can go Walmart and get one that will do the trick for about $20 and you can use it for a lot more than antenna work.
Software
This could turn into a huge list, but I’ll try to keep it under control.
Software can be more expensive than the hardware, but there is some very good news…many of the antenna software packages are either low cost or totally free. Most packages have both Windows and Linux versions (a few have ARM versions for Raspberry Pi) or there are workarounds to your OS. Sadly, I know of only a limited number available for iOS in native mode. I have no information on running these packages on iOS…the last Apple product I owned was an Apple II-GS.
Essentially, what you need is a software package that will help you design and analyze antennas. Just by using the modeling software, you will also learn a great deal about how and why antennas, and the related systems like feed lines, work. Just as an example, you can design a simple ½ wave dipole and see how the current is distributed on the wire and what impact making the wire longer and shorter might have. Then you can add parasitic elements around that dipole wire and see what happens to the radiation pattern. You will see, in real time, why we call this arrangement a “beam” antenna.
While there are many packages out there, they are all more or less similar, but the user interface varies. It really comes down to personal preference as to which one you should use. I’m only going to touch on two packages here…
EzNEC – Up until the first of 2022, EzNEC was commercial software, but the author decided it was time to retire and released this fine package for free. This is a Windows system (7 or above) but it runs just fine under Linux in an Oracle VirtualBox setting. EzNEC has a rich list of features and functions, and is a great choice. I use EzNEC myself for most of my modeling needs, but like so many feature rich, easy to use software packages, there are some things that are more or less hidden and very difficult to access.
MMANA-GAL – This is a package from Germany that is also very powerful. It uses a slightly different model than EzNEC so sometimes will come to slightly different solutions. MMANA-GAL defaults to German (no matter what the website says) and changing to English can be a bit of trial. This also is a Windows program, but MMANA-GAL runs perfectly under WINE in Linux. I also use this one when I need to get down and dirty and into the details of the antenna.
In either case, there are a number of good/excellent user guides, YouTube videos, and mailing lists to get support.
Hardware
Now, here is the part that’s going to get you in trouble with the XYL…you need a junk box, a junk pile, and someplace to work. Actually, you’re going to need several boxes and piles for junk. But it’s all in how you look at it…
Some people (like your XYL) will see boxes and piles of junk. You (and me) will see antennas in the raw. It’s kind of like pork chops…there’s little as pleasing as a nice, thick cut pork chop waiting to go on the grill to be transformed into a wonderful, juicy meal. But all your XYL will see is a dirty, nasty pig in the back yard.
Anyway, that’s your problem…
Gather old TV antennas, you know, the big ones that had half a mile of aluminum tubing involved. Get any kind, size, and length of wire you can find. Look for hunks of plastic, nylon, and similar insulators. Screws, bolts, nuts, washers, and other fasteners, especially brass, are like gold.
Never even think about throwing away that 2’ length of coax. You’re probably going to need that!
If you have a project working and you need to buy 5 PL-259 connectors, always buy 10. You’re going to need them, too. And I can promise you that you will ruin a few of these.
And then are the other odds and ends…metal pipe and conduit, PVC pipe and fittings, rope and cord, hose clamps, and just about anything else you can imagine.
In short, look at everything through the lens of building antennas. Ask yourself if that gizmo you’re about to throw away could be used in some way in some design. Odds are, it can.
Yes, I have a toaster, two microwaves, and non-working apartment refrigerator in my junk pile.
And in closing, I want to leave you with this warning:
Building antennas is addictive. There should be a warning from the Surgeon General on the cover of the ARRL Antenna Book.
But as the saying goes, it is a fine and enviable madness.
In our next installment, we’re going to take a DDD…that is, a Dipole Deep Dive to discuss how (and why) they work and why on the order of 99% of all antennas are based on them. More importantly, we’re going to look at a few variations you can build right now.
Take Care & 73
de KC6UFM
Charles