Big Zapper HF Antenna | HF Doublet | All band HF Antenna | 600 Ohm Ladderline | Parallel Lines

Added: 2026-05-07

[00:00:04]Welcome to our channel. My name is Sophie and my papa's name is >> Darren. My call sign is N4 VFR.

[00:00:14]>> In this video, we're going to build a big sapper antenna.

[00:00:23]>> Cool. You ready?

[00:00:25]>> Yeah.

[00:00:28]This portion of the video, I'm going to show you where I got the information on building the big zapper. So, there's a document that I found online. I want to bring it on screen. So, this is a newsletter from the Central Virginia Contest Club. This is dated back in September 2008. In this newsletter, when you scroll down, you get to a an article that's showing you the antenna calculations. And here it is. So, the designer was Jim. His call is November 4 Mike X-ray Zulu. And this article was submitted by Whiskey Kilo for Yankee.

[00:01:13]His name is Chuck article into the newsletter. This is how you calculate the length of the wire, your antenna portion. So in this example, you take 468 divided by the center frequency. In this situation, it's the 160 m band 1.850.

[00:01:35]That equals 252.97 ft. Then you divide that by 2, you equals 126. That's 126.48. 48 ft. Write that down and that number is right here.

[00:01:50]You take that answer divided by 2 again and that equals 63.24.

[00:01:57]Then you add that number to your 126.48 and it comes out with a total length of your antenna element is going to be 189.72 ft. And you divide that by two that equals per side 94.8. 86 ft. Now for the feed line portion, you take the same formula. 468 / the center frequency equals 252.97 ft. You take that answer, divide it by 2, it equals 126.48 ft. It's the same as the formula above.

[00:02:37]Then you divide it by 2 again and that comes out to 63.24 24 ft with the 450 ohm feed line. That's going to be your length 63.24 ft. So it's the same formula up here for the antenna and that's calculating your feed line. So this 63.24 ft, that's your actual ladder line length. I found this also on the internet when I was doing some research for the Big Zapper. This was posted by RD Bentley on 31 October, but this is the HF band that it covers from 6 through 160 m and the total length was 192 ft long. So up here is the T where you have it. It splits into two sides. You got the the left side and the right side. So this side is going to be 96 feet and the right side is also 96 feet. So it's a little bit longer than that formula that we saw earlier on the the PDF. So here the length per side was 94.86 and on this picture here it's 96 ft on each side. The length of the ladder line is 65 ft. here using the 450 ohm and coming to the formula for the feed line it is 63.24 ft. So you see that there's a couple inches longer in this plan here. So let's take a look the big zapper HF antenna. Number one, it uses 96 ft quarter wave per leg. They use a copper solid wire 14 gauge or 12 gauge and the total length is 192 ft. Number two, it uses 65 ft matching stub feed feeding the 450 ohm ladder line and 14 gauge is the standard specification. Number three, for best results, installation should be at a height of 40 ft at a minimum. Number four, the center should be supported and the end should be raised or lowered for an impedance of 100 ohms on 80 m. Number five, it provides a perfect match on 80 and 160 m by using a 2:1 balon at the feed point.

[00:05:12]So your feed point is right here where you see so 239. It's right here in the middle. Number six, it is also optimized for the 40 meter band. And number seven, an automatic tuner should function properly with this antenna. And right here at the bottom, it's designed by N4 MXZ.

[00:05:34]And it was modified by W4 COX. And take note here on these uh image here, you need at least a 50 ft 50 ohm coax that feeds to the 2:1 balance. And also there's a note here, no balance needed.

[00:05:50]So that's uh that's kind of strange.

[00:05:52]Have you guys ever used AI? This is Claude AI. I asked Claude, "What are the differences in using 450 ohm ladder line compared to a 600 ohm ladder line for a double HF antenna?" So I'll let you read all that here. I'm just going to go straight towards the practical differences for the 450 ohm ladder line.

[00:06:17]It's this here, this column.

[00:06:19]Construction is manufactured. It's uniform spacing availability. You can purchase it uh over the counter.

[00:06:28]Durability, it's robust. It handles the wind and ice very well.

[00:06:35]In regards to close proximity to objects such as towers or or buildings, it's more tolerant for nearby objects and walls. In regards to water and ice like rain or snow, window line somewhat is susceptible and the cost is inexpensive over the shelf and handling it. It's easily to route and it's somewhat flexible. Now over to the 600 ohm open wire. The construction is normally home brewed availability. It's not as common as the 450 ohm. The durability it's more fragile because the spacers can be shifted. In regards to close proximity to buildings or towers, it's more sensitive and they need more clearance from structures. Now with rain or snow or ice, they said here this is important for those that live in those environment. It's more immune since there's no dialectric and the cost. It may cost a little bit more because you got to buy the wires, the insulators and the zip ties to construct the open wire.

[00:07:47]And last for handling, it's stiffer and requires more careful routing. So which to choose? And Claude says, "Go with a 450 ohm windowed ladder line if you want practicality. Buy it today solution and it's readily available. It's durable. It works excellent for any kind of double it or the big zapper application that I'm going to be building here. And uh slightly higher loss versus the 600 ohm is completely inconsequential in practice. Or you can go with the 600 ohm open wire line if you want the absolute the theoretically minimum loss. You're home brewing this uh antenna your feed line and you're running high power is greater than 1 kilowatt and want every marginal improvement. It's also the most classic approach and works well in open rural settings where routing away from structures is easy. Bottom line for the vast majority of HF doublelet installation 450 ohm wind windowed ladder line is the pragmatic winner. The electrical difference is negligible and it's far easier to work with. The tuner will handle either one with equal ease and you'll be hardressed to measure the loss difference in the air. These are the websites for the product materials that I'm using. This is your 6in heavywalled tube insulator and this is from Kenco Farm Fence Supplies. So, I bought uh I'm not sure how many I bought, but I this is what I'm using right here. As far as the zip ties go, I'm using uh zip ties from Amazon. You see right there, Amazon. This is 16 in in a pack of 100. Uh very important to have a UV resistant zip ties and it's used for outdoors. For the wire that I'm using, this is Davis RF flexeave. It's an amateur radio uh product flexeave and I believe I'm using the number 12 flexeave. I think it's uh this one here, FW12 Papa. So that's what I'm running here.

[00:10:08]All right. some of the equipment or materials that I'm running here is the zip ties. These are 16inch zip ties. Uh I I bought two packages. I don't know how many I'm going to require, but these are UV resistance. Very important because out here in Florida, we have beautiful sunshine all day long. Uh this is important here. We decided to go with a 500 ft strand of Davis RF 12 gauge wire. This here are our 6 in spacers.

[00:10:45]So, I bought two packages. Again, I'm not sure how many I'm going to require.

[00:10:48]I went ahead and bought a bundle of two.

[00:10:51]I bought these off of eBay. And I got some uh various uh insulators, the dog bones here. I'm going to space them out 12 in. And we have this concrete plate that you see here that my mom used on her her patio, homemade patio, by the way. So, this is about a foot long. And I have a measuring tape here to measure out my my distance required. This is that 500 ft long of 12 gauge wire. And we're going to cut each length or each wire to >> 161 ft long. So, let's do that. Now, we're going to measure it out.

[00:11:33]>> Puppy >> C.

[00:11:36]>> Can you help me?

[00:11:37]>> Sure.

[00:11:40]>> R N for Q and C gave this to my puppy.

[00:12:12]It's a search protector.

[00:12:26]Tada.

[00:12:28]>> Okay, I'll hold this end. All right. And make sure it's you walk nice and straight backwards. Okay. Go ahead.

[00:12:36]>> We have to see the wizard. The wizard of us. We have to see the wizard of the wizard of us. We have to see the wister of the wizard. Because they are up because because because because because of the way he huffles.

[00:13:01]>> Did he get tangled?

[00:13:03]>> Yeah.

[00:13:03]>> Okay. Keep going, baby.

[00:13:18]All right. So, I only got a 100 foot of uh measuring tape. Um, so we're going to have measure 100 ft, tape it off, and then measure 61 ft afterwards. All right. So, I'm going to have you go ahead and pull back. Okay. Ready? Go ahead and go.

[00:13:34]>> Mhm.

[00:13:36]I I I >> All right, I'm going to try to be as accurate as possible. I'm going to try to start here. This is going to be 100 foot mark.

[00:14:12]Right here is 100 ft.

[00:14:18]Just going to tape it. This is going to be 100 ft.

[00:14:22]And then we need to go 61 ft that way.

[00:14:25]What you're going to do is I'll hold this now and you're going to pull this wire to the end of the measuring tape.

[00:14:33]Okay.

[00:14:33]>> But the this >> Yeah. Just go as close as you can.

[00:14:38]>> All right. Keep going.

[00:14:44]All right. So, this is again the end 100 ft. And I'm going to measure out another 61t.

[00:14:55]from here.

[00:15:16]So that's 161 ft long of 12 gauge wire.

[00:15:23]So, what I want to do is I'm just going to run another pair along the side of it and measure it out and cut it off. And once that's done, I'm going to mark from where the the surge suppressor is going to be located. From that point, I'm going to measure 65 ft up to the the apex. And that's where I want to put another blue tape. The blue tape will signifies that's where it's going to go to the top and then wise off to the tea.

[00:15:52]So, this is the good end, and this is the the new one. We're going to pair it up like this and measure 165. They're going to be 161 ft. They're going to be the same.

[00:16:11]Now, that's the end, and that's where I'm going to cut it. Okay, I'm going to cut it right here.

[00:16:18]So, this these two wires are the ends.

[00:16:22]One's going to be a positive, one's going to be a negative. Uh, they're not going to be touching. So, what I'm going to do is I'm going to go ahead and add a ring connector to the end of this and attach it to the surge suppressor.

[00:16:38]This is a surge suppressor.

[00:16:41]One side's going to be positive, the other side is going to be negative. So, I got to make sure my ring connectors will fit this.

[00:17:00]I'm taking it. It's probably this size here.

[00:17:05]That's what it is. So, I'll need two of these.

[00:17:35]Now that we have uh a starting point, we'll measure 12 in from here. Every 12 in, we'll add a spacer. Okay, the next thing I'm going to do is I need to measure out 65 ft. I'm going to mark it with a blue tape.

[00:18:01]This is 65 ft. Okay, we got to measure it out, tape it off, and that's where we're going to stop the ladder line.

[00:18:09]Okay, this is my first time doing this.

[00:18:11]Let me see if I do this correctly. Yeah, Sophie's first time, too. Go through the tube around the first wire. Go back inside the tube >> and then then there >> and then into the the zip.

[00:18:34]>> Pull >> and you pull it.

[00:18:38]Okay.

[00:18:40]So, that's uh how we're going to do it.

[00:18:42]So, we'll do one on this side and then we're going to alternate on the other side. Since this is already one in, I'm just going to eyeball it to say that's going to be we'll stop over here. Okay.

[00:18:57]I won't cut these yet. Yeah. See how that moves a little bit? So, it needs to be one more click.

[00:19:06]There you go.

[00:19:08]That's nice and stout.

[00:19:09]>> So you go in.

[00:19:23]>> Yeah, you need >> you need to feed it more. See all this extra slack? You need to push that in >> and then push the top back in. Okay.

[00:19:41]Did it come out the other end?

[00:19:43]>> Yeah.

[00:19:52]>> All right. So, there you go.

[00:20:01]>> Ready?

[00:20:03]She doesn't have the strength. See how loose it is.

[00:20:13]Now I can cut this one off >> like this.

[00:20:20]But this should be like this. And then here Papa He's there.

[00:20:32]Okay.

[00:20:34]So, we going down like this.

[00:21:00]Where is heat?

[00:21:39]How's it going?

[00:21:41]>> Good.

[00:21:48]You want me to help you, >> puppy?

[00:21:52]>> I'm sorry.

[00:21:55]Try again.

[00:22:10]See you there.

[00:22:14]Let me see. Sometimes you get this backwards. So it's this is not This is backwards.

[00:22:20]So let me show you something.

[00:22:23]>> How to know that it's backwards?

[00:22:25]>> Okay.

[00:22:28]I'm going to waste this one. Okay. So you see the shape of this?

[00:22:34]>> Yeah.

[00:22:35]>> See the the box is on top. So you put >> box have to be on top. So yeah, and you put the the tail inside the box from the bottom because if you did it to the top like this, it's not going to work. See?

[00:22:51]See? It's supposed to catch and then it goes loose.

[00:22:55]So make sure um >> the box have to be on top or down.

[00:23:01]>> Okay. When you're going, the box is going to be down.

[00:23:04]>> Have to be Okay, >> you got it.

[00:23:06]>> Okay. Let me let me walk.

[00:23:49]You got it. That's it.

[00:23:51]>> But it's upside down.

[00:23:53]>> Huh?

[00:23:54]>> So it have to be >> Yeah. See, but you got to pull it. See, now you feel it. Pull it. You can hear it. Click, click, click. You feel it?

[00:24:02]Okay. All right. Before you tighten it all the way, we need to make sure that this is all right. So, pull that up to the top of there. There you go.

[00:24:14]Just like that. And then tighten it.

[00:24:19]>> Want me to do it? Cuz um >> Yeah.

[00:24:22]>> Yeah.

[00:24:23]>> It's too hard to pull it because mine I have a lot of >> Yeah, cuz you're I know you're you're a little weak there, but that's fine.

[00:24:32]Well, I'm gymnastics.

[00:24:35]>> You go to the gym. You see it right there? You can see how the box is almost like flush and it gives it like a nice wedge on the inside.

[00:24:45]>> Okay.

[00:24:45]>> Yeah, baby girl. Go ahead and do another one.

[00:24:50]>> Okay.

[00:24:53]Okay.

[00:24:57]Box up. I have to put it like this.

[00:25:03]box.

[00:25:05]This is fun.

[00:25:12]>> Okay. But we I want that the box hit here.

[00:25:18]>> Okay.

[00:25:19]>> Yep.

[00:25:20]>> So I I can I can know that I can take Oh, it's going up. I don't want to go up.

[00:25:32]Okay.

[00:25:43]Huh?

[00:26:05]puppy.

[00:26:12]>> What we got?

[00:26:13]>> Okay. You want me to tighten it?

[00:26:15]>> No, but I I don't know. You >> straighten it out.

[00:26:19]>> Straight.

[00:26:20]>> Yeah.

[00:26:21]Okay.

[00:26:22]>> Okay.

[00:26:33]Okay.

[00:26:51]And how how >> use this uh diagonals and cut it right no right here. Yeah.

[00:27:03]>> How?

[00:27:03]>> Get it closer to the box like this.

[00:27:05]Diagonals like that.

[00:27:08]Okay. Squeeze.

[00:27:11]>> Very good.

[00:27:13]>> That's all for >> Yeah, that's it for now. Let's keep going back.

[00:27:22]>> Keep going, baby.

[00:27:24]>> More.

[00:27:26]>> Yeah, we got to go 65 ft.

[00:27:28]>> What?

[00:27:29]>> 65?

[00:27:30]>> Do more. I can't.

[00:27:34]>> It's getting dark.

[00:27:35]>> Okay.

[00:27:35]>> All right. Here you go. Keep going, baby. So, we did it on this side. Now, you're going to do on this side. Box down.

[00:27:42]Yeah, puppy, can you put it straight, please?

[00:27:49]Please, please, please, please, baby, please.

[00:27:53]Okay.

[00:27:55]No, stupid.

[00:27:59]>> There you are, baby.

[00:28:09]>> This is number five. So, it's about 5 ft right now.

[00:28:31]>> You get it done.

[00:28:36]>> I think it was too long like No, you got to push it through and then you have to try to push that through and then wrap it around this.

[00:28:51]>> How?

[00:28:52]>> How?

[00:28:54]>> All right. So, this is got to go. That has to go up.

[00:28:58]Push push it through like that. You see how now you have slack?

[00:29:03]>> Yeah.

[00:29:04]>> And then pull it here.

[00:29:08]See that?

[00:29:11]Do you see the you see the uh what do they call that? The the light the light bulbs glowing.

[00:29:20]>> Mhm.

[00:29:22]>> Let me show you again how it looks like from the bottom angle. So the zip tie box there is wedging against the wire and you pull it as hard as you could and this won't move.

[00:29:38]Eventually it'll move in severe weather.

[00:29:41]You know what I'm saying? Wait, wait.

[00:29:43]Other way. Other way around. See those diagonals? They go this way. Up against up against. Okay. The diagonals.

[00:29:58]I think you got to go to the gym.

[00:30:04]No, I you need some strength. You see how you got a gap there? We don't want that. You want to get it as close you like it >> there.

[00:30:15]>> Watch your fingers. And then snipped off.

[00:30:21]You got it.

[00:30:22]>> Okay. Okay.

[00:30:23]>> You got it. How many do we have to do?

[00:30:26]>> When the sun sets, we got to keep working.

[00:30:31]>> Too much.

[00:30:36]>> This is hard. Well, not not too hard, but it's hard to put it.

[00:30:45]I don't know.

[00:30:46]>> Have I got a gun? I got a gun to shoot these freaking birds.

[00:30:53]Two.

[00:30:54]>> The box is up. The box need to be down.

[00:31:02]>> You did it wrong.

[00:31:03]>> Again, wasn't catching >> because a bird.

[00:31:10]>> Because the bird distracted you >> upside down.

[00:31:13]>> Yeah.

[00:31:15]>> Did you see the box is up? You see that, >> buddy? Turn it around.

[00:31:20]The box needs to go down.

[00:31:22]>> I put it down.

[00:31:24]>> All right. So, I twist it like this. All right. I'm going around.

[00:31:30]Put it through. See, the box is down.

[00:31:36]There you go.

[00:31:38]All right. So, I came through and put it in.

[00:31:49]What do they want?

[00:31:52]>> That's tight. That's tight. Okay. Use the diagonals and and snip it there.

[00:32:08]Okay. One, two, three.

[00:32:15]Good job.

[00:32:22]We're almost to the end of the ladder line. So, the tips of the blue, these are the ends where it's going to be uh connected to this uh I don't know what they call this, the apex, the the T connector. Well, it's not a connector.

[00:32:40]It's a continuous run 12 gauge wire. So, at the bottom of these blue tape, that's where we're going to uh split apart. So, I'm just going to line these up.

[00:32:56]Since this is the thicker part, I'll put the the pan head on that side. So, this is the thinner part. See how thin it is?

[00:33:05]So, this is the thicker end.

[00:33:23]So, what I did is uh I'm going to put where the blue markers towards the middle of that hole there. And that's where it's going to be inserted inside.

[00:33:34]So, I got these tight enough so I can actually move the wires back and forth and then have the exact measurements.

[00:33:41]I'm going to put those wires in that hole and then loop it outwards. I took the blue tape off. I'm just going to work with one end. So, that's 65 ft right now of ladder line up to the top.

[00:33:56]Now, we're going to have 95 ft on each leg. So, it's 95 ft of wire I'm going to have to route through there.

[00:34:10]Look at the wire. It's just limp. It just falls.

[00:34:15]There's no memory to it.

[00:34:25]So, look at that.

[00:34:28]Goes in nice and easy. And uh I'm going to go back in that hole and then come around and then go back in this hole.

[00:34:52]That's what it looks like so far.

[00:34:55]Feels good in Florida. A little bit of light breeze.

[00:35:08]I'll do the same thing for the other side on this end. The same process.

[00:35:13]There it is. The big zapper. Each leg is about 95 ft long. This is how it's connected.

[00:35:26]The ladder line, it's a 600 ohm ladder line. It's about 65 ft long. And for Q&T Art uh made this for me, like Sophie said. So, one side is positive, the other side is negative. That's going to be connected to the ground and that's where I'm going to be running a at least 50 foot of coax. I think I'll be running the Messian Paloney. Let me show you how long it is. I had to fold it. So, from the box, it's running all the way behind the SUV.

[00:36:13]Okay. And if it folds over and then it goes back to a table.

[00:36:23]So that's 65 ft long.

[00:36:25]>> Thank you for watching our videos. My name is Sophie and my papa's name is >> Darren. My call sign is N4 VFR. Hey guys, if you're new to my videos, please consider to subscribe, leave me a like, and a comment for us. We'd like to thank you for watching again. Have a great day. 73s. See you.