Posted: 3/25/2026 8:24:22 PM EDT
[Last Edit: Omni][Edited]
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Are homebrew antennas witchcraft, magic, and voodoo powered? Do I need to provide the blood of a fresh Technician as a sacrifice to have them make sense? Received my Stick 500 on Monday and have been playing around with it. Tried making a dipole out of 16g speaker wire and a cobra head. I looked up the lengths, double checked the math was right, and then cut the legs a foot long on each side. Hung it up in a slanted upside-down V and started taking readings. An hour later and I had cut off over two feet from each side and no matter what I do, cutting, double over and wrapping, it always has a high SWR on any freq. I'm obviously doing something wrong and need more practice. Took a reading on my EFHW and it read all four bands that it was described as having when I bought it. SWR was not the greatest on any of them; but my rig can tune them fine. Then for shits and giggles I took it inside and took a reading off of the receive only dipole I have in the attic. This is used for feeding my computer-based software radio and SDRsharp. When I installed it, I used a roll of surplus army trip wire, a cobra head, and that small as hell 1/8 thick Chinese coax wire with SMA connectors on each end. The coax is running down the inside wall from the attic and right past all of my power cable for the computer. I didn't measure any leg lengths on the dipole since it was for receive only and I wanted as much wire as possible. That half assed antenna is resonate on 14 different bands and half of them have SWR less than 1.6! WTF ?? |
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"Good SWR" on your crappy attic antenna might be loss in even crappier Chinese spaghetti coax. Get a wide-band sweep device like a Rig Runner or nanoVNA and find out where the dipole you tried first is resonant. It's gotta be - somewhere. If not, you have a hardware problem, perhaps in the cobra head feed point or a short or open in the feedline. Let us see the leg lengths you calculated as a starting point. |
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What he said ^^^ Originally Posted By Omni: snip That half assed antenna is resonate on 14 different bands and half of them have SWR less than 1.6! WTF ?? A dummy load will have a <1.5 SWR on all bands. Do you have a nanoVNA? They're really helpful with antennas and especially learning/understanding them as you can see the SWR over a span and what little changes in position, height and length will do. |
| Is your slanted upside-down V near any metal, near the house etc? Antennas couple to metal around them. How long are the legs and how high in the air is it and how close to something else. It is all about wavelength distance away. |
Mach
Nobody is coming to save us.
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Nobody is coming to save us.
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Something is up for sure. I made a speaker wire antenna with the banana plug bnc connector, inverted V off a tenkara rod. Thing was like 1:1.1 after trimming. Got quite a few contacts and all the way to the far side of Spain on it. I can’t remember the YouTube guy whose video I followed but he later got brain cancer and passed. I think his tutorial was on the HRCC YouTube show. Here is his first video before HRCC had him on.  How to make a Ham Radio Speaker Wire Antenna |
“ Well, it feels like someone took a rubber band and snapped it right on the edge of your anus.” -JThompson
Non Solis radios sed Iovis fulmina mitto
Non Solis radios sed Iovis fulmina mitto
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Originally Posted By Sierra5: Something is up for sure. I made a speaker wire antenna with the banana plug bnc connector, inverted V off a tenkara rod. Thing was like 1:1.1 after trimming. Got quite a few contacts and all the way to the far side of Spain on it. I can't remember the YouTube guy whose video I followed but he later got brain cancer and passed. I think his tutorial was on the HRCC YouTube show. Got it to 1.8 with no tuner, Unun, balans or any magic. I made contacts from SE Mo, all over the upper North and West States, then all the way over to Slovakia. With good signal reports. Strange thing, no matter where I spun the thing or oriented it, it seemed like I still got contacts in the same areas. |
LARUEMINATI
NRA Endowment Life Member
Originally Posted By Boom_Stick:
""AKs are for villagers you have to tell not to shit in their water supply.""
NRA Endowment Life Member
Originally Posted By Boom_Stick:
""AKs are for villagers you have to tell not to shit in their water supply.""
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You would need the blood of a new General, not Technician, just saying... As others have said, low SWR is only one indication that the antenna *may* work properly. All of my HF antennas are home made, although I don't wind my own baluns/transformers. Every one I have made has requied trimming, as much as several feet. Because of this, I (almost) never measure accurately, I trim to my NanoVNA readings. Trimming or adjusting with a single frequency reading is about impossible, and when things aren't right, you can have multiple SWR dips, within a MHz or so, which go away when things get fixed. Start with confirming the coax is not bad. I had a PL-259 connector go bad on one of my coax, and readings were all over the place. Replaced it, things are working again. For this reason, I always take extra coax when I go portable. If the coax is good, make sure the wire lengths are the same, or close to it, and check the cobra head to make sure it doesn't have an issue, stray wire or something. Confirming the coax is good depends on what you have available. Simplest method is to swap it out and see if anything changes. Or, with a NanoVNA, you can measure the coax, or even check it for continuity with a multimeter. A dipole more than 15' above the ground, and the ends more than probably a few feet, not too close (15'?) to a metal object, should be below probably 1.5 SWR. A dipole may not get much below that due it the design, but that is fine. As mentioned, losses in the "small as hell 1/8 thick Chinese coax wire with SMA connectors on each end" will make the SWR look better because of losses in the coax. |
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Okay, I come from an era where only professional 2-way radio shops had an SWR meter and they weren't about to loan it out. We cut our antennas per the formula, strung 'em up in the trees, and worked the world in our blissful ignorance while running a single 807 or 6146 with a power output of 40 to 50 Watts. Our transmitters did have Pi-network output stages which had a very wide matching range. People overly obsess about SWR. If your radio can match the load, you're going to get out. To decrease the received signal by one S-unit, the power must be reduced by a factor of four. IOW, 100 watts down to 25 Watts, 3/4 of your power is going up in heat warming the transmission line. This month's QST has a good article about this. How to tune an antenna If you're going to be playing with antennas a lot, buy yourself a Nano VNA. They're amazing little devices and educational to boot. LINK There are plenty of videos on TouTube showing how to set up and use them. ETA: Be careful where you buy a VNA. There are many knockoffs that are POS. |
"...Capitalism...shares its blessings unequally; ...Socialism...shares its miseries equally."
Winston Churchill
Winston Churchill
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Originally Posted By smullen: I made my 1st HF 10m antenna out of a large T Shaped structure from 3 lengths of PVC pipe and a T, then taped 14 ga Speaker wire from the HW store on it with black tape Soldered a PL259 connector in the middle, then cut to tune. Got it to 1.8 with no tuner, Unun, balans or any magic. I made contacts from SE Mo, all over the upper North and West States, then all the way over to Slovakia. With good signal reports. Strange thing, no matter where I spun the thing or oriented it, it seemed like I still got contacts in the same areas. I’ve noticed rust also on different antennas. For example, me and the back side of Spain are very well aquatinted. And in winter I get Chile all the time. |
“ Well, it feels like someone took a rubber band and snapped it right on the edge of your anus.” -JThompson
Non Solis radios sed Iovis fulmina mitto
Non Solis radios sed Iovis fulmina mitto
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Originally Posted By Sierra5: I’ve noticed rust also on different antennas. For example, me and the back side of Spain are very well aquatinted. And in winter I get Chile all the time. I rarely have a rust problem with antennas, but I do get Chile in the winter, especially if I stay outdoors for long. |
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For those wishing to build or experiment with wire antennas, I have found these banana binding posts to be very helpful. They make simple work to connect wires to coax. You can use them for dipoles, verticals, whatever you like that doesn't need a blaun. I used them on vertical and a Delta Loop before moving to more permanent, i.e., weatherproof, solutions. You will likely need a PL-259/BNC adapter if you don't already have one. I have left them outside for a while, but they will tend to rust after a week or so. But for portable, or trying things out, these work! Attached File |
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Originally Posted By Frank_B: Okay, I come from an era where only professional 2-way radio shops had an SWR meter and they weren't about to loan it out. We cut our antennas per the formula, strung 'em up in the trees, and worked the world in our blissful ignorance while running a single 807 or 6146 with a power output of 40 to 50 Watts. Our transmitters did have Pi-network output stages which had a very wide matching range. People overly obsess about SWR. If your radio can match the load, you're going to get out. To decrease the received signal by one S-unit, the power must be reduced by a factor of four. IOW, 100 watts down to 25 Watts, 3/4 of your power is going up in heat warming the transmission line. This month's QST has a good article about this. How to tune an antenna If you're going to be playing with antennas a lot, buy yourself a Nano VNA. They're amazing little devices and educational to boot. LINK There are plenty of videos on TouTube showing how to set up and use them. ETA: Be careful where you buy a VNA. There are many knockoffs that are POS. A NanoVNA can be used, among other things, for measuring your antenna's SWR and will also generate a Smith Chart. It is a relatively low cost open source type of product meaning that the circuits and parts are known to all, so every cheap overseas sweatshop can crank them out using the cheapest parts they can find. So, quality varies. That is why I bought from R&L, thinking they were at least a reputable place that knows ham radio, so wouldn't sell junk. This is the one I have and have been using for over 3 years without any problem. I see that they offer a few different ones now, so if I were buying today, I would look at all of them.  I am running the NanoVNA from a PC so I don't have to torture myself with the cheesy little touch screen, plus I get the results on the large PC monitor so can see the results more easily and do things with them. The free NanoVNA-Saver software makes a HUGE difference in how easy it is to do things. The software can be found here: https://github.com/NanoVNA-Saver/nanovna-saver |
Don't confuse where I live with where I'm from.
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True. I ordered the 2.8" screen because I wasn't sure how useful it would be. Had I know known then what I know now, I would have gotten the 4" screen. Those numbers are really small for these old eyes. What I really like about it is that if the open/short/load calibration procedure is performed at the antenna end of the feedline, all feedline effects are nulled out and the readings are those for the antenna only. |
"...Capitalism...shares its blessings unequally; ...Socialism...shares its miseries equally."
Winston Churchill
Winston Churchill
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Originally Posted By Frank_B: True. I ordered the 2.8" screen because I wasn't sure how useful it would be. Had I know known then what I know now, I would have gotten the 4" screen. Those numbers are really small for these old eyes. What I really like about it is that if the open/short/load calibration procedure is performed at the antenna end of the feedline, all feedline effects are nulled out and the readings are those for the antenna only. Not sure I follow you. Why look at the tiny screen on the unit when you could see it on a PC or laptop screen instead? |
Don't confuse where I live with where I'm from.
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Originally Posted By Mach: Is your slanted upside-down V near any metal, near the house etc? Antennas couple to metal around them. How long are the legs and how high in the air is it and how close to something else. It is all about wavelength distance away. This just might be the cause of all my issues. The antenna was on the backside of the shop right next to the wall. I had the rope thrown over the metal strut channel that my mast is anchored to and the cobrahead was pulled up tight to it. Thanks for the suggestion everyone, sometime in the next few weeks I will find a different place to give it a try and see if I can make it work. |
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Originally Posted By Emoto: Not sure I follow you. Why look at the tiny screen on the unit when you could see it on a PC or laptop screen instead? KISS, man, KISS. Keep It Simple, Stupid. Lugging a computer out to my antenna disconnect point is a real PITA when I'm trimming the antenna. |
"...Capitalism...shares its blessings unequally; ...Socialism...shares its miseries equally."
Winston Churchill
Winston Churchill