What's Better: Ground Plane or Tiger Tail?

[00:00:00]All right, I got some stuff here. I got some wire here. This is actually leftover DX10 wire from a DX Commander antenna. And then these guys here, I'll have a link in the description below, but you can get these at Walmart, Tractor Supply, Harbor Freight, etc. These are just your Ace Hardware everyday run-of-the-mill, I mean, Home Depot fork connectors, terminal connectors, crimp-on connectors, whatever, butt splice connectors.

[00:00:24]But this you have to get from my buddy on Etsy. This is a case specifically designed for the SW-102, which you guys have seen in previous videos. And normally what I do is I put this ground plane on and they've made it really hard. They stopped including the ground plane, and so I've been showing it with the ground plane, and it's kind of unfair. The only way to get this ground plane is to pay more for the ground plane than you do for the meter by going to Short Comm's website and getting it directly from there. So, what I'm going to do today is I'm going to make up some tiger tails. And these tiger tails will work great with your radio without even having this, and they'll improve the range of your radio.

[00:01:03]But your radio needs to have an appropriate ground plane in order to do testing, and that's where this comes in.

[00:01:10]That way every ground plane is exactly the same for every antenna that I've tested up until now, cuz I'm going to be making the tiger tails.

[00:01:19]So, what a tiger tail does is it is the other half of the antenna. Most antennas have a push and a pull side of things, and that push-pull deal is the left side of the antenna, the right side of the antenna, the ground, and the center that you know, the shield and the center conductor on your coax and and that kind of thing.

[00:01:37]But on an HT, it's usually you. Let me grab one real quick.

[00:01:43]It's usually, you know, your your hand grabbing onto the radio creates your body into creates makes your body into that other half of the antenna.

[00:01:55]And depending on what you're wearing, if you're wearing gloves, if you have on more clothing or less clothing, no naked ham radio, then you wind up with a better signal. And so, the way to force and guarantee that you get the same signal every time is to create a tiger tail. For 2 m, it's really straightforward. It is 19 in of wire, and that's just the wire length.

[00:02:16]Don't worry about the connectors or anything.

[00:02:18]We're trying to be a little more precise. We're not trying to be that precise because there's so many factors that go into this. For 70 cm, it is 6 and 1/2. And so, I need my wire cutters.

[00:02:31]And I need 6 and 1/2 in of wire. Each one of these is a 1/2 in from there to there. 6 and 1/2 in. And so, 6 and 1/2 in is And we cut it. Perfect.

[00:02:49]And if you know that you're never going to use 70 cm as an example, or if you just want to have the utility, you can do one fork connector, one spade connector, one ring terminal, one one whatever. But, I'm going to be doing this test a lot, and so I'm actually going to terminate them both into the same end.

[00:03:07]There they are.

[00:03:09]Into the same connector.

[00:03:11]And so, I'm going to use these guys here.

[00:03:14]And then, where's my meter? I'm going to make sure before I go through all the trouble and crimp this thing down.

[00:03:19]Now that I've got my wires cut, that that actually fits over there. And it does fit over there just fine.

[00:03:25]Can I put that on?

[00:03:30]I think we've got a winner there. And I'm not really a fan of those blue plastic covers on there, so I'm actually going to take that off. And you can heat them up to slide them off, and that looks like that's what's going to be needed right now.

[00:03:50]Ta-da!

[00:03:52]Don't breathe in the fumes. They're pretty bad for you. Known to the state of California to cause cancer. And then I need wire strippers, and these actually also happen to be a simple set of crimpers, and we'll see if that gets the job done or not. But with these, I can set my my depth gauge, which is going to be just a little bit.

[00:04:12]And maybe just a little bit more than that.

[00:04:17]And we'll put those together.

[00:04:23]Cross them over into one.

[00:04:27]And then I've got enough wire to go through there.

[00:04:30]Plenty, but I'm actually going to fold it in half to give it more surface area to crimp onto.

[00:04:35]And then that goes in there, and then we will try a crimp here, or should I use my other crimp tools?

[00:04:48]Okay, there's one. All right. And I'm going to dress that up with a little bit of heat shrink, too.

[00:04:55]All right.

[00:04:56]There we go. And so we've got the 19-in piece for the 2-m antenna, and we've got the 6 and 1/2-in piece for the 70-cm antenna. And RF is pretty cool. It's actually going to pick the one that is the most resonant to send the most of its signal out of, and so that's why you're able to get away with this.

[00:05:13]And this is kind of the same principle behind a fan dipole, and it'll be just fine.

[00:05:18]Because this obviously isn't any very specific measurement. This is just a lot of metal underneath of the antenna. This is a little bit more of a specific measurement, and is a lot of metal under the antenna, but not as much metal.

[00:05:32]So, what I want to do next is some side-by-side comparisons, and then we'll be able to get this thing all put away in the case. But while I'm here at the at the desk, I will show you this really neat little case that my buddy Jared made.

[00:05:45]What I do with my Short Com is I'm always testing out HT antennas.

[00:05:51]And so as an example, I have this little stubby antenna which a lot of people think is a dummy load or just a a high quality resistor or even a low quality resistor. And what I'll what I do is pull it off, figure out whatever end it is that's on there, and then this is the end that goes on the output side, the antenna side.

[00:06:11]And then I can put this on right here.

[00:06:16]And this is usually about the time when I realize that I forgot to put the ground plane on, but now it doesn't matter. Now I can put the whole antenna on and I can put my tiger tail on instead.

[00:06:29]And we're good to go. The problem with putting the antenna on first is that the ground plane doesn't fit over that. So then I wind up taking the whole thing off.

[00:06:37]And on this side here, I have the the other gender of the antenna connector, and that goes directly into the radio.

[00:06:50]And if you happen to have a radio like a Yaesu that's got the other kind of antenna connector, then the beauty of this is I can just take this one and put it over here and this one and put it over here, and then we've got a good match again.

[00:07:05]So let's give this guy a test while we're inside and see what she says.

[00:07:17]All right, so this is 2-meter calling frequency and high power, and we're using the tiger tail, and we get 5:1 SWR. Not very good.

[00:07:29]3-something watts out.

[00:07:33]Now is that because I'm inside of a great big metal box, or is that because that's really just a bad antenna?

[00:07:42]So we'll put the ground plane on and we'll test that same antenna again. So, we get a little bit better SWR with the ground plane on, but we'll check it again outside. Okay, so now you know why I have a male end and a female end on that, so I can swap out for different types of antennas and different types of radios.

[00:07:58]But, there's also room in the case for BNC male and female, so I can put this in line between those two types of antennas. And then there's room there for the short com meter itself. And then believe it or not, I've had this thing for a couple of years and I've never had to charge it. I've never even taken the twist tie off of the charger socket. And who needs one of these? I haven't even taken the wrap off of this thing, either.

[00:08:23]But, that will fit in there if you're if you're the kind of person that does feel like you need to charge it all the time.

[00:08:29]That'll fit in there.

[00:08:30]And if you actually use this a little bit more, maybe you'll be able to get the the cable in there nice.

[00:08:37]There we go.

[00:08:38]So, she's all set with the cable and the charger in there. But, like I said, I don't use those and this is micro USB and I since I do a lot of Raspberry Pi stuff, I have a bunch of those. So, what I'm going to do instead is I'm going to put my tiger tail in there.

[00:08:58]Then we get some extra stuff in here.

[00:09:01]A random color SMA wrench for cinching down your SMA connections.

[00:09:08]And then some directions, but we don't need directions. That's what we make videos for.

[00:09:13]And some of these guys here. This case is nice enough to have a What's the opposite of recessed?

[00:09:20]Obsessed?

[00:09:21]Um place to put the stickers and he's included single-sided stickers instead of double-sided stickers. If you've seen me build these things in the past, the double-sided stickers are fun with a capital F to put on cuz they stick to your fingers when you're trying to get them stuck in there.

[00:09:38]And what this does is it stops the meter from rattling around inside the case and provides a little bit of a connection there for it.

[00:09:47]And so now, I've got all the tools that I routinely use, plus some extra BNC connectors. I don't really don't use these, but the holes are there, so I might as well fill them up. The meter fits in good. I've got my SMA connectors. I've got my tiger tail. I've got my wrench. You can put the cable and the charger in there if you use it. And I just found out, I'm going to do a future video if possible, where there is a drop-in replacement for these micro USBs, where you unsolder this, unsolder desolder this from the circuit board, and you put in a USB-C connector, and it's pin compatible. You know, excuse the the borrowing of the phrase, but it's pin compatible and mostly size compatible. You can see it's a little bit of a D shape for the micro USB there.

[00:10:27]And I can put a USB-C in there. So, if it works out to be a video on doing that in the future, and if you never see one, it either I didn't get around to it or it doesn't work. But now, all of that fits in there very nicely, and we are good to go with some protection for our instrument, and it matches the other cases that Jared has. Let me show you those real quick.

[00:10:46]This one here is for the TinySA, and inside it's kind of the same thing, except this time there's room for your TinySA, and there's a false bottom for all of your TinySA toys.

[00:10:59]And that goes in there very nice. And then, if you happen to have See, that's why I need to protect my instrument. If you happen to have a NanoVNA, he's got the same thing set up for these guys here, where there's room for the NanoVNA inside and a false bottom for all of your NanoVNA toys, your open short and load, some unions, another couple of adapters if you need them, whatever else you'd like to add to round out your collection here.

[00:11:24]And these are made custom for each of the different sizes of the TinySAs and the NanoVNAs.

[00:11:31]And again, they'll be linked in the description down below. Now, let's get outside and compare that same cheesy antenna with the ground plane and the tiger tail and see if this metal box RV is causing additional reflections and that's why it looks bad or if this is just a bad antenna. And I'm as far away from the metal box as I can be. The only thing I've got nearby is a pine tree.

[00:11:51]Kind of like the one behind me, but it's right over here. And we're set up with the stubby antenna and the ground plane and I'm going to run it.

[00:11:58]4.43 on the SWR, the big number there in the center of the screen.

[00:12:04]Which also makes us down to 3.29 watts out in power. Let me change this over real quick.

[00:12:11]Get rid of this ground plane and we'll try it with the tiger tail.

[00:12:14]So, it looks like the metal box hasn't changed anything so far.

[00:12:18]Which makes it easy for me. Now, I can do the whole thing at the bench instead of having to get outside. I hate being outside.

[00:12:27]All right, there's my tiger tail. Put the antenna back on. And let's run the test again. 2-m high power.

[00:12:33]5.33. So, it's 5.23. So, it's the same inside as it is outside. Now, some of you guys might be saying, "But that's that's only a a UHF antenna. If you look at the the label on there, it says VHF UHF."

[00:12:47]So, I'll take your word for it that it's a VHF antenna. Let's put this on a VHF frequency. There's the 70-cm calling frequency.

[00:12:55]And we're keying up.

[00:12:57]Ooh.

[00:12:58]15. I saw 15 to 1. 14.65 to 1 SWR. So, this antenna is no good.

[00:13:06]So, that's going in the bin. We need another stubby antenna.

[00:13:10]So, if you guys have any recommendations for a stubby antenna, leave them in a comment down below.

[00:13:15]And I will leave a link where you can get the Surecom meter and the SW-102 case and the NanoVNA case and the TinySA case, as well as these really cool coax adapters that you need in the description down below for you as well.

[00:13:28]So, what I've got here is my favorite radio, the Vero VRN76, the Surecom SW-102 meter, the ground plate that is made of pure 100% pure unobtainium, and a 10-W dummy load.

[00:13:42]And if we run that same test where on high power 2-m call, we get 1.02:1 SWR, big number right there in the center.

[00:13:52]So, what I'm going to do is I'm going to do some surgical relocation and get rid of this ground plate and put in my tiger tails. Let's do it in real time for you guys.

[00:14:03]There you go. 1.01:1 SWR, 1.02:1 SWR. So, depending on how long I hold down the the key and where the peak is, we're pretty much exactly the same with the tiger tails and the ground plate that you guys can't get.

[00:14:20]Let me show you something about this dummy load here real quick. Oh, you got me dinner. Yeah.

[00:14:27]You probably don't have your little baby camera. I do. What are you doing over here? I'm testing SWR on an antenna and I don't want the metal on the side of the RV to reflect the signal back at me.

[00:14:38]>> you just stay out of my damn business?

[00:14:39]It's none of your damn business, Dan.

[00:14:41]All right. Thanks. [laughter] I'll see you later. See you, bud. This is why I like living in RV parks.

[00:14:46]Everybody's always so friendly. Dan's like, "I'm not interested in radio at all." A very wise man once said, "A difference that makes no difference is no difference."

[00:14:54]And so, that's your 100th of a decimal point of SWR difference. But, let's take a look at the case now, too.

[00:15:00]And I've already talked to Jared about this, and I'm sure that this can be fixed cuz this is all doable in software, but there's your meter, there's your SMA and BNC adapters, there is my dummy load. And my dummy load is 30 mm wide, and this section of the case here is 28.8 mm wide. So, she fits in there, but she's a tight fit.

[00:15:23]And then also, in case I happen to need it, I've got my SMA union, my SMA wrench, and the SMA wrench comes with the case. It's pretty cool. And the tiger tails that we built. So, if you put that in there, and then you got to kind of start it on the round side, it fits in there like so.

[00:15:39]And we are good to go in case you need a dummy load for your testing. Okay, this is what I like about working with small businesses. This is the first case that I showed you, and there's another case underneath of it. So, what happened was this dummy load was a little tight. So, I told Jared about it, and my boy fixed it. This is awesome. Let's move this over, move this over, move this over, move this over, move this over, get this out.

[00:16:10]We've got Where is it?

[00:16:13]A little union that's left.

[00:16:15]That can go in there, the tiger tail that we made up, and now this guy just fits right in there.

[00:16:22]It's not a squeeze fit anymore. It's a fit fit.

[00:16:28]Perfect.

[00:16:33]So, dummy loads are super cool. They come in all different shapes and sizes, and they also come in different frequency ranges. So, make sure when you get a dummy load that you pair it up with the amount of power you're going to be putting into it, and the frequency that you're going to be using.

[00:16:46]And also, I've got a really cool one from Cellwave that has a little tap on it, so that I can put high power into it, and then sample out lower power RF into like an oscilloscope or something like that without blowing it up. Some of the things that I use a dummy load for are for communicating with myself inside of the same shack. So, that way I can set up two 2-meter radios and do packet communications back and forth while I'm testing out something with the Toads DI or some piece of software that I'm loading, and I can guarantee the other side of the transaction is there and I can tell what's going on between the two. It's no longer is there a hill in the way? Is the other station down? Is RF propagation not very good for me today? I've got two radios side by side. I control both ends of the conversation and I'm not splattering RF all over the planet trying to solve a little software problem that I'm working on for a video for you guys. Dummy load to do let out a little bit of RF, but not as much. So, if I put a 100 W dummy load on to a 100 W radio and I do key down, I might get half a watt. I might get 2 W, but I'm not getting 100 W and I'm not making everybody in the 300-mile radius upset at me. Same thing with 2 m. I might be able to put a 50 W dummy load on there and get out half a watt or 2 W and I'm not making everybody unhappy in the 30-mile to 80-mile radius around me.

[00:18:09]So, they are definitely necessary for testing. And if you've got an amplifier, especially one of those old tube-type amplifiers, you want to get that thing all in tune between the radio and the amp before you stick an antenna on it.

[00:18:19]So, that's where the dummy load comes into play. Dummy loads are real sensitive to heat. So, if you are using a dummy load for an extended amount of time with a high-power radio or with a low-power radio and a low-watt rated dummy load, check to make sure it's not overheating because you're going to start to see your SWR creep up as the dummy load gets too hot and it's not going to be effective for blocking RF anymore and it might actually cause some damage to one side or the other of those things. So, short key down, get the job done, get out of there, let the dummy load cool.

[00:18:49]So, a little bit of mechanical empathy is what I call that. Well, that certainly was a lot of fun getting that all figured out, getting it all reorganized for in the case and everything. You can see from the stubby antenna and from the dummy load that everything affects everything and this is especially true when it comes to HT type radios. The way you hold it, the way the wind blows, the amount of clothing you have on or don't have on.

[00:19:15]Again, no naked ham radio. How much metal and stuff is around you? Right now, I'm inside of a box that's got metal siding on the outside of it. So, that's going to actually bounce signals back into me. And that's going to cause some problems. What really matters here is the scientific method. Create a reference point. Create a control. Come up with a hypothesis. Test your hypothesis and prove the answer to yourself. This W antenna has got some really high SWR. However, not to make any defenses for this, by the way, but I have been told, an old ham's tale that is, I have been told that HTs are a little stronger when it comes to SWR mismatch tolerances, number one.

[00:19:57]And number two, these operate in pretty much the worst environment you can imagine because that environment is every environment. If you have a base station in your car, it's a pretty fixed environment. The radio doesn't move, the antenna doesn't move in relationship to its ground plane, the ground plane doesn't change all that often, maybe a little bit of rust over time, kind of thing.

[00:20:19]And then your reflected surfaces are what's out in the area around you. And usually you're not close enough to those kinds of reflected things that it's going to make a huge material impact.

[00:20:30]Your home station, you've got a fixed antenna up on a mast somewhere, you've got a J-pole hanging from a tree, whatever the case may be. It is also relatively stationary. I use this in my shack. I use this in my car. I use this out walking. I take this into hamfests, which are even bigger metal boxes filled with even more people with more antennas just like this.

[00:20:49]This has got to be the most hostile RF environment that a ham can do.

[00:20:55]But now, we've got a tiger tail system set up, so no matter what we have the same reference plane. We've got a dummy load that we can test against. We've got a known good antenna that I could bring in, like the antenna that we all know and love.

[00:21:09]And really what I'm trying to do is verify power output, which would be use the dummy load, or verify a quick check on the SWR to make sure that I'm not so far out of spec as to be causing stupid harm to my radio.

[00:21:23]That's science. Here we are.

[00:21:26]We know that everything affects everything and it's all about your environment. And I will leave a link for the case and the dummy load and the coax adapters and everything you need in the description down below. But now I can put that ground plane to rest and save some space in my workshop.

[00:21:44]And you guys can check out this video right over here. I think you'll enjoy next. Thanks for being awesome. I'll see you over there. Oh yeah, be sure to like and subscribe and all that stuff, too.

[00:21:52]Much appreciated.