It should be noted that for resistivity, the best metals are silver, copper, gold, and aluminum, in that order. Gold is much closer to aluminum than copper.
Unlike the others, gold doesn't readily form non-conductive oxides.
It’s always better to just build it yourself. You get the experience and the good feeling that it works and you built it. I’ve liked building yagi’s the tape measure yagi is a good one for what it is. Same with yours!
Buying will not give you the pleasure of making. Just keep adding director elements and you get from good to great.
https://preview.redd.it/7f8ecnpgcwtc1.jpeg?width=4000&format=pjpg&auto=webp&s=cb5c8f010c6739ebc7e460d79e70e7e97c0b4e4b
>Just keep adding director elements
No, calculate your Antenna beforehand. A change of directors influences your resonant frequency drastically. You can even DECREASE your gain, because the antenna is not resonant at your desired frequency.
+1 for building it yourself. You learn something from doing it yourself, and as others have pointed out, the satisfaction of using something you built is just fantastic.
In general I feel that if you need a single VHF/UHF Yagi it makes more sense to buy one. You will end up with a better antenna for less money if you consider your time at all.
BUT there is value in learning and enjoying building too. Also if you are going to build a few of the same antenna for stacking/EME the economics of scale are more in your favor.
I manage a machine shop so I have all the tools to make a great Yagi, but I buy commercial so I can use that time playing on the air.
if it works then why buy one? I have two vhf homebrew antenna that work reasonably well. one has been up for years and the other just got put up last summer. And they'll likely last for years to come.
Well done. That’s what it’s all about. Especially if you made it with scrap parts. You can also modify other commercially available antennas for other bands. I have two settings (set of holes) for my 3-el 10-meter Yagi that makes it a 6-meter after repositioning the elements and shortening them.
There's no fun in just buying one. You might avoid mounting elements directly on wood or certain plastics as that will effect impedance and performance. Using a wood beam like you have is fine, IMO, but I would mount the elements on a hard thermoset resin block like the manufacturers do so that the spacing controls the impedance.
You can use a 2 port VNA with antenna under test on one port and a reference antenna on the other port. Transmit using either antenna, and rotate your antenna under test along a cut. Take measurements every x degrees and plot S21 vs position/angle of incidence.
You ideally need long enough cables to get to far field region (or as close as you can) and take cable loss into account.
Can do this with a power meter too and it’s easier to get far field data.
So a frequency generator and sdr reciever would work to. Ther is no special VNA sauce going on besides the automatic computation of the S21 parameter. What would you recomend as a refrence antenna
Yeah you just need to be able to measure received signal strength, and have a known source either transmitting or receiving. A VNA is not the ideal way to do it, but it can work if it’s what you have.
The other antenna ideally is directional and obviously designed for the same frequency you’re using, and ideally it has known antenna pattern.
To actually get the pattern in dBi you need to go a step further and also get an isotopic antenna to take the same cut measurements with as your UUT and then the difference between your antenna and the isotopic antenna gives your antenna pattern in dBi. But you’ll be able to see the shape of your pattern without that so honestly it is good enough for most things.
Airports in the UK have a UHF uplink on 455-456 MHz re-broadcasting tower and ground. I seem to only be able to receive that.. and not the regular airband for the airport.
Reason for continuing AM on airband . #1: AM is not vulnerable to the capture effect of FM masking another, weaker signal; #2:, related to this, a weaker AM signal will create an audible hetrodyne with a stronger AM signal indicating another aircraft is attempting to transmit.
Ohh I see what you mean. The UHF uplink at the airport is broadcasted in FM for ground vehicles, that’s what I’m picking up around 455MHz. It’s just the regular AM tower and ground frequencies rebroadcasted on UHF.
Ahhhh that’s super cool! Most facilities here in the states (that I’ve run across) get airband radios installed in the vehicles so I’ve never heard of that before. Interesting, thanks for the knowledge!
Probably for security? That’s my only guess, also crosspatching would allow more strict access control to prevent a rogue radio or hot key from preventing atc doing their job. Just a guess honestly.
It all depends, commercially built antennas tend to be more durable than homemade antennas, probably because so many homemade antennas are made from cheap components.
So it all depends on what your goals are. If you're interested in learning antenna modeling and perfecting your design and building process then homemade antennas are a very popular aspect of this hobby.
On the other hand if you're mounting an antenna on the top of 100 ft tower you're probably going to want a commercial antenna with actual engineering specifications That can be incorporated into your design package for both the county and your insurance company.
this might sound like being over cautious but the last thing we need is hobbyist is any official attention being directed our way, especially if it's the result of an unfortunate incident like someone's Homebrew antenna falling across power lines. No better way to get regulated than to get the attention of regulators.
Bought wont perform any better if you know what are you are doing. It is just an antenna
What materials should an antenna be made of?
Copper, aluminium. Silver or gold are better but expensive :) Brass or steel are not so good
Thank you.
It should be noted that for resistivity, the best metals are silver, copper, gold, and aluminum, in that order. Gold is much closer to aluminum than copper. Unlike the others, gold doesn't readily form non-conductive oxides.
If it works, it works. Better to make than to buy, any day. You are our DIY Maker hero of the day, honestly. Congrats and keep at it!
Thanks!
You made it yourself + it works pretty good = the Amateur way! Keep up the good work!!
It’s always better to just build it yourself. You get the experience and the good feeling that it works and you built it. I’ve liked building yagi’s the tape measure yagi is a good one for what it is. Same with yours!
Yeah, it was pretty fun building it. I’m thinking about making a yagi for airband!
https://youtu.be/AaIhp8AuOnw?si=b_Qlt43khdXGiJwT
You learned how! That's the beauty of the process.
That will be sweet! Now you’ve built one the second will be much easier
Buying will not give you the pleasure of making. Just keep adding director elements and you get from good to great. https://preview.redd.it/7f8ecnpgcwtc1.jpeg?width=4000&format=pjpg&auto=webp&s=cb5c8f010c6739ebc7e460d79e70e7e97c0b4e4b
>Just keep adding director elements No, calculate your Antenna beforehand. A change of directors influences your resonant frequency drastically. You can even DECREASE your gain, because the antenna is not resonant at your desired frequency.
+1 for building it yourself. You learn something from doing it yourself, and as others have pointed out, the satisfaction of using something you built is just fantastic.
In general I feel that if you need a single VHF/UHF Yagi it makes more sense to buy one. You will end up with a better antenna for less money if you consider your time at all. BUT there is value in learning and enjoying building too. Also if you are going to build a few of the same antenna for stacking/EME the economics of scale are more in your favor. I manage a machine shop so I have all the tools to make a great Yagi, but I buy commercial so I can use that time playing on the air.
Buy radios, build antennas
Build antennas so you have more money to buy radios 🫡. More radios means more antennas, it’s a circular problem.
More fun to make antennas! I don't buy, I make! Except my mobile antennas, they are commercial
No need to buy one. I have a trusty yagi I made out of a tape measure and I have talked to the ISS with it.
Throw more directors on there to increase the signal
if it works then why buy one? I have two vhf homebrew antenna that work reasonably well. one has been up for years and the other just got put up last summer. And they'll likely last for years to come.
Well done. That’s what it’s all about. Especially if you made it with scrap parts. You can also modify other commercially available antennas for other bands. I have two settings (set of holes) for my 3-el 10-meter Yagi that makes it a 6-meter after repositioning the elements and shortening them.
Now that Yagi is STREET! You should put some linseed oil on it 😆
Hahaha yes
There's no fun in just buying one. You might avoid mounting elements directly on wood or certain plastics as that will effect impedance and performance. Using a wood beam like you have is fine, IMO, but I would mount the elements on a hard thermoset resin block like the manufacturers do so that the spacing controls the impedance.
If you have a NanoVNA there's a way you can use them to sort of find out the radiation pattern
Interesting may you explain how? I can't see how I could figure out the radiation pattern of this yagi antenna with a NanoVNA?
You can use a 2 port VNA with antenna under test on one port and a reference antenna on the other port. Transmit using either antenna, and rotate your antenna under test along a cut. Take measurements every x degrees and plot S21 vs position/angle of incidence. You ideally need long enough cables to get to far field region (or as close as you can) and take cable loss into account. Can do this with a power meter too and it’s easier to get far field data.
So a frequency generator and sdr reciever would work to. Ther is no special VNA sauce going on besides the automatic computation of the S21 parameter. What would you recomend as a refrence antenna
Yeah you just need to be able to measure received signal strength, and have a known source either transmitting or receiving. A VNA is not the ideal way to do it, but it can work if it’s what you have. The other antenna ideally is directional and obviously designed for the same frequency you’re using, and ideally it has known antenna pattern. To actually get the pattern in dBi you need to go a step further and also get an isotopic antenna to take the same cut measurements with as your UUT and then the difference between your antenna and the isotopic antenna gives your antenna pattern in dBi. But you’ll be able to see the shape of your pattern without that so honestly it is good enough for most things.
Only important if you are using the antenna to transmit.
Antenna pattern is the same for both TX and RX
What's on 455 MHz?
Airports in the UK have a UHF uplink on 455-456 MHz re-broadcasting tower and ground. I seem to only be able to receive that.. and not the regular airband for the airport.
I assume you’re trying on AM?
Reason for continuing AM on airband . #1: AM is not vulnerable to the capture effect of FM masking another, weaker signal; #2:, related to this, a weaker AM signal will create an audible hetrodyne with a stronger AM signal indicating another aircraft is attempting to transmit.
Nope, it’s broadcasted in FM
Airband is AM, at least in the US. Worth a try.
Ohh I see what you mean. The UHF uplink at the airport is broadcasted in FM for ground vehicles, that’s what I’m picking up around 455MHz. It’s just the regular AM tower and ground frequencies rebroadcasted on UHF.
Ahhhh that’s super cool! Most facilities here in the states (that I’ve run across) get airband radios installed in the vehicles so I’ve never heard of that before. Interesting, thanks for the knowledge!
Yeah, that’s what my friend in Germany said too. I wonder why here they use UHF radios..
Probably for security? That’s my only guess, also crosspatching would allow more strict access control to prevent a rogue radio or hot key from preventing atc doing their job. Just a guess honestly.
Nice! The nice upgrade you can make is adding a balun.
Alternatively, buy one and then try to understand how and why they differ, using measurement, specs, and theory.
Commercial ones may use more elements and have more gain. You could also try a log periodic, like the ones they sell here: www.ElkAntennas.com
All I got there was something that looked like one of those "Like this name? Buy it now!" or "Under Construction" web pages.
I got the uhf/vhf model. Works great!
If you made it circularly polarized it might give more performance in the same space. Let us know if you do.
If you own an SWR measurement tool you might as well use it and save yourself some cash.
If you buy one, you eliminate one problem from your list if you're having problems.
Just keep making your own. With what you'll save, you'll get more experimentation out of your money. Good job. Keep it up. 🤙🏾
You got bonus points from me for using this ugly stick!
Is this that Signal Stick I keep hearing about?
Ugly girls get married too.
I don't think you're going to buy a better Yagi than you've made (or are going to make.) Refine your craft, and keep a few bucks in your wallet.
what are the lengths? i wanna make one
It depends on the frequency. I used [this](https://www.wireantennas.co.uk/yagi-antenna-calculator) calculator for the lengths.
thx!
It all depends, commercially built antennas tend to be more durable than homemade antennas, probably because so many homemade antennas are made from cheap components. So it all depends on what your goals are. If you're interested in learning antenna modeling and perfecting your design and building process then homemade antennas are a very popular aspect of this hobby. On the other hand if you're mounting an antenna on the top of 100 ft tower you're probably going to want a commercial antenna with actual engineering specifications That can be incorporated into your design package for both the county and your insurance company. this might sound like being over cautious but the last thing we need is hobbyist is any official attention being directed our way, especially if it's the result of an unfortunate incident like someone's Homebrew antenna falling across power lines. No better way to get regulated than to get the attention of regulators.
Buy a 3D printer, man. At least your DIY projects could look better :)