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[Articles Home]  [Add Article]  

Nearly Cheap Homebrew QRP Vertical

rick fineout (KB2NAT) on October 8, 2018
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Ideally, I wanted a portable antenna that was effective, didn’t have an extremely narrow bandwidth, was easy to carry, small, set up quickly and did well on DX. There must be a solution that doesn’t cost much…isn’t there?

First, I must say that I do have a mag loop and it works very well. It does, however, require some fine tuning and is subject to reacting to its surroundings which can be iffy in both home and travel. In addition, they are not cheap, and mine doesn’t remotely tune unless I want to add to the price and I don’t have the remotest idea of why I should spend more on it.

A large, albeit efficient, mag loop is not easy to travel with, either by foot or air. I could get a smaller (less efficient) one, but I’ve found that many surroundings in hotels and even beaches, often preclude their effective use. They are great for the right circumstances, but I have a penchant for not being in them.

A great idea is to simply use a couple of wires with a BNC connector with my KX3. Elecraft suggests a basic pair of 25’ wires and they are reasonably effective and my KX3 can tune them easily, as well as the other lengths I’ve tried. The KX3 can even tune the BNC connector…but, many times there aren’t appropriate structures to hang a wire on. Barring levitation, kites or balloons would just add stuff that I don’t need to add to my little go bag. I’ve used a bush, a low tree, or a signpost, as a support when nothing else was available, and the NVIS approach works well, but of course, not for DX. At least the price is very reasonable for 50’ of wire, especially at a garage sale where $2 can often buy a half roll of 500’ wire, but it’s inherently limited.

So I looked at a growing plethora of portable QRP antennas advertised out there and found that they were either costly ($90 for a just a coil?), really small (read inefficient), or too toy-like. End-fed antennas work well, but there is still the support issue. At the beach lifeguards apparently don’t want you to run a wire to the top of their beach stands.

I priced some verticals, and starting at the bottom, I looked at tripods for them. One was a slight variation of a camera tripod for $125…it was just like the one I bought at a garage sale for a few bucks and gave to our son. Another is small, very packable, but $90 was still a bit much. Then there’s a complete “deployment” kit that comes with two real counterpoise wires (with fittings) that will, for about four C- notes, have you bursting with deltoids, standing on a snow- clad mountain talking into a microphone with your head six inches from the radiator while QSO-ing with everyone who wants to communicate with a ham with deltoids on a mountain. I wondered about that one.

There’s also a tripod available with a telescoping pole for $160 and there’s a little one that comes apart in three little metal sticks with a small center section that has been threaded for an antenna for only about $80. There’s also an antenna that looks like it was designed by a spider and would cost two boat payments, but is directional. I would end up trying to put it together in a poison ivy patch, or a wind tunnel. Am I the only one who’s retired, makes car payments, yet wants to take his wife to dinner from time to time and keep things simple?

Some of the reasoning for buying showroom equipment I’ve heard is, “You bought an expensive transceiver, so you should spend lots of money for peripherals!” Part one precludes part two of that statement. It’s a HOBBY, not the definition of my masculinity…so what to do?

Fortunately, I hit many garage sales. As a result, I no longer need mobile mounts, coax, cables, work benches, vices (?), or pliers. I’ve obtained so much of that stuff on the cheap that hams run from me. “Oh no, he wants to give us more antenna cables!” My emails offering free cables are unanswered! Seriously!

I started to watch more videos of what other hams do…one guy has a machine shop, drill press, lathe, welding gear and seven racks of oscilloscopes, Hammarlunds and every Zenith Transoceanic ever made. I wanted to send him a picture of my Tivdio V-115 SW receiver ($19 on eBay). I have a condo. My tools are a hammer, some basic tools, a tall garbage can, a tiny desk vice, a soldering gun and a Dremel. I do have meters of various sorts that sit in a small drawer in my desk.

But I continued to persevere and several dozen videos later, I recognized that a lot of clever hams have had some great ideas and many of them are of the money-saving home-brew variety. And one day at a garage sale, I saw six pieces of one- foot aluminum tubing that screw together to form something that would look like a portable antenna that would cost $175 if it were made in California. How well, I thought, would that work for portable hamming? A dollar and six feet of aluminum tubing later, I was hooked on making my own portable, inexpensive, DX-eating, (semi) wide-band antenna.

Of course, that meant a few other auxiliary parts, like a coil, tripod, pole mount, and a cheap, long, skinny bag to carry it in, cable and solder. I was already half-way there. The garage yielded some one-inch PVC pipe— thin, easy-to-trip-on-and- hard-to-see (but useable) wire; and, I had enough antenna parts to make my own coil.

One ham used corrugated plastic hose which he cut into strips and glued to a support on which to wind a coil. Clever! I had some of the same stuff which I had previously used to cover sundry antenna cables coming into our house years back, so I cut it into four narrow seven-inch strips and glued them on the sides of a one-inch diameter PVC pipe to hold the wire. I drilled holes into two round PVC caps, installed the 24x3/8’s antenna hardware and bought a bolt to fit the odd six aluminum small pipes which would make up the radiating element. I used a wander lead with an alligator clip to connect to the coil to find points of resonance.

Part of a rotatable dipole bracket would work as a pole mount for the coil . Oh yes, the tripod—I had an old mic stand (garage sale; it came with six mike cables, two other mic stands and assorted audio cables: $10!). The basic tripod, extension and base were perfect for this purpose.

I mounted the bracket on the stand, the coil on the bracket, the aluminum pole on the coil and connected the antenna cable to the antenna analyzer (MFJ-I bought it direct). But the antenna was lopsided and crooked! The round caps were just impossible to evenly mount an antenna on, no matter how clever the hams were whom I watched do this in the videos. However, I took some readings, anyway. I found that I actually could tune down to 14 MHz, even if the coil and rods looked funny. Then I thought about my MFJ 1979T telescoping antenna (Christmas gift from the XYL). I replaced the hardware to fit the more conventional threads (24x3/8) and managed an SWR below 1.5:1 down to 6.5 MHz. I tried adding two one-foot extensions. However, it only dropped the lowest point of resonance down to 6.4 MHz. I guessed it would be easier to add more coil to reach 80 meters rather add than antenna length. Of course, if the antenna were straight it would look a bit more professional as well.

To increase inductance to get down to 80 meters, I made a coil that was 8” long and doubled the diameter to 2” with PVC pipe and some more slices of corrugated tubing as a wire guide. Instead of 12’ of wire, I used 36’. Instead of round caps, I found a pair of flat ones with screw-in inserts in which to mount the antenna receiving hardware. I used the same wander lead and with the coil and added 17’ telescoping antenna, I could now get down to 3.55 MHz with a usable SWR of 1.5:1 or better.

It measured well with the analyzer with the same three 25’ radials I had used before, so off I went with the antenna, tripod, KX3 and associated gear to our local gazebo in a small field to see how it all worked in practice. I had no problem matching the performance to the measurements. My little six- foot antenna with coil had given way to something much larger, but still practical. The MFJ 1979T and all else packed up well with the mic stand being the longest piece of about 27”. It all worked surprisingly effectively, even if I wasn’t on a mountain top with a tight t-shirt over my big deltoids. But there are, however, some rather important afterthoughts.

The first was that it wasn’t quite as cheap as originally planed. The hardware was already on hand, because I was cannibalizing previously used materials, but if I were starting from scratch, the cost would have risen easily by $40-50. And if I hadn’t had the $60 telescoping antenna, I would have had to buy one or use a lot of coat hander wire—very uncool. Another of those afterthoughts was to raise the antenna to its maximum height once it was on the tripod. It gives some vertical help to the radials and gives two less feet of wire for people (me) to trip over. This (and an 6 knot breeze) brought forth another afterthought: that was to carry three or four ground stakes (they don’t have to be large) and cords with adjusters. The 17’ antenna, fully extended, develops a surprising amount of wind loading. My cheap bag wore a hole in one end, dumping everything out. Time for a new bag… either a garage sale acquisition (over some time) or some material and some sewing machine time (the XYL volunteered here), so I don’t yet have a bag that will work for toting the coil, antenna, and my converted mic stand. I can’t see this being a big cost. I mention it because finding a weakness in the stitching or a hole in cheap material can leave parts invisibly in the woods forever.

So How does it compare to a good mag loop? It’s cheaper, easier to transport, but is not quite as good in performance. The mag loop also demands some freedom from metal objects which could leave you stranded. The vertical is noisier, but more consistent in its performance and more useful in more places. It also requires a bit more time to put up, but not much more. The mag loop covers 60-6 meters; the vertical covers down to 80 meters and the KX3 ATU would tune it down to 160 meters, which would also see a big drop in efficiency. Both antennas lose efficiency as the frequency drops, of course. It wasn’t as cheap as I’d hoped, if one considers the cost of buying what I had on hand (the MFJ telescoping antenna, the hardware, etc.) However, it is enjoyable to just spend an afternoon with something you built yourself—even if it’s a wire thrown over a branch—helping to send those QRP watt(s) into the ether. And looking at the prices of many of the antennas out there, I guess I didn’t spend that much after all.

Member Comments:
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Nearly Cheap Homebrew QRP Vertical Reply
by KM0U on October 8, 2018 Mail this to a friend!
Thanks Rick, for the article. I enjoy reading what others have tried or are doing regarding QRP. I agree that some of commercial gear is expensive for what you get. I use portable verticals but find for multiband use, it's hard to beat the ease of a radiator and counterpoise with a good tuner (toss - tune - operate).
I came across some cheap teflon #22 wire at a local surplus store for $.02/foot so bought a 1000 feet. I've been doing a lot of experimenting with toss in the tree antennas.
My favorite portable vertical is the PAC-12 when trees are not available. It is light, packs well, sets-up quickly, and doesn't need a tripod or clamp - just spears into the ground.
 
Nearly Cheap Homebrew QRP Vertical Reply
by KF7ZFC on October 8, 2018 Mail this to a friend!
Rick: Thanks for the article. I am in a HOA situation and am building a copy of a flower pot vertical antenna system by WA5DJJ. Building with limited tools and finances is both fun and what a lot of ham radio is about. What loop antenna are you using?
 
Nearly Cheap Homebrew QRP Vertical Reply
by K4BAD on October 9, 2018 Mail this to a friend!
Good story..Particularly liked the part about the KX-3 ability to tune a BNC connector.....Great humor.
I've been using a MFJ "Big Stick" portable vertical with great results....worked lot's of European DX on 20 meters and,most surprisingly, Australia and New Zealand on 40 meters.Honest!
Using ICOM-7300 for above contacts.Cost was about 100 bucks for the antenna.
 
Nearly Cheap Homebrew QRP Vertical Reply
by KD8ZM on October 9, 2018 Mail this to a friend!
Try the W1SFR end fed wire, supported by the MFJ-1910 collapsible fiberglass pole. I set the end-fed's box on the ground and use a 35' counterpoise wire also on the ground. Works 40-6 meters with a antenna tuner. Man does this setup work well! And it sets up/takes down in just a few minutes.
 
RE: Nearly Cheap Homebrew QRP Vertical Reply
by KJ4DGE on October 10, 2018 Mail this to a friend!
Just took a store bought 20 meter dipole and mounted it on a 25 foot piece of bamboo pole hanging from the top. Secured the SO-238 at the bottom and ran 8 counterpoise wires from the "ground" end in different directions. Worked 2 Florida stations with a 57-59 signal and one in Alabama. Takes up less space and can mount it just about anywhere next to the house with the top in the clear. First home-brew vertical I tried and I like the results.

If you have a painters pole or other long non-conducting vertical base try a vertical!
 
Nearly Cheap Homebrew QRP Vertical Reply
by ND6P on October 17, 2018 Mail this to a friend!
Back in my hiking days I used a vertical. It was made from the base section of a Hustler mobile antenna that doubled as a walking stick to help with the hiking. The rest of the antenna (mounting plate, radials, 12' telescoping whip, center coil for 40 meters, and coax) fit in my backpack. This antenna was great for mountain tops where there were no trees to hang wires.
 
RE: Nearly Cheap Homebrew QRP Vertical Reply
by N3HAM on October 29, 2018 Mail this to a friend!
Check out Ed WA3WSJ's web site for his version of the Black Widow wire vertical. I use it with my PFR3 rig since it matches the 3 bands it has. Quick no fuss deployment and no need for sky hooks.
http://wa3wsj.homestead.com/BW.html
 
Nearly Cheap Homebrew QRP Vertical Reply
by WD0BCT on November 18, 2018 Mail this to a friend!
An excellent article! It shows that using one's own gray matter, bulging deltoids, and whatever materials at hand one can create something that works. Material cost can be kept low but the satisfaction derived is priceless!
 
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