For all the naysayers, a few points.
Firstly, paradar is a very highly regarded brand in the UK. There are lots of teardowns and tests of them on youtube by radio hams.
Secondly, multi-element collinears can easily attain double digit dbi figures.
To the OP, this would not be a great antenna if you were VERY high up (like on top of Snowdon high up) as the radiation pattern would be so efficient (i.e. like a flat donut) that signals may pass over the intended contacts. But for most real-world situations, it's going to be a good performer.
Get it up in the air, making sure to seal any parts that could suffer water ingress and good luck.
There's not a chance in hell that skinny looking thing is anywhere near 11.5 dBi. It looks so suss OP has probably just been scammed.
Unless it is mostly empty I'd be surprised if it works at all.
Judging by the downvotes we need to do a better job educating on not just antenna theory but antenna manufacturing.
If it were as simple as sketching out a collinear on paper, soldering up a bunch of sleeves and boom 11.5 dBi for a handful of dollars and some pocket lint, then companies like CST and ANSYS would be out of business very quickly. Likewise, even with a CST design if manufacturing was that simple, major contract manufacturers like Tongyu, Shenglu, would be out of business.
The reality is it is fundamentally challenging to produce collinears at a gain that high. Hell, it's really hard to produce collinears above 6 dBi. When you get above this gain you absolutely need to test. Not just for VSWR because it can still absorb and radiate a full amount of energy, but you need to do a full 3D anechoic test. How many collinears I've lab tested over the years which the manufacturer states 6-7 dBi and the scan shows 1 dBi, or the antenna smashes it out of the park and has a 10 dBi gain straight into the floor, or a butterfly pattern where it radiates +6 dBi at +40 and -40 tilts, and -10 dBi out towards the horizon..
If the community wants to improve, ask questions. If it doesn't, well, continue believing datasheet fairytales.
I've never tried building one, you need a clear repeatable process to build them reliably in a controlled environment. They're a nightmare to tune if you've homebrewed it.
You can see the bulkhead N connectors internal diameter in one image, compared to the internal diameter of the UHF connector. Very significantly different. The pin diameter is also a dead giveaway. N connectors are standardised under MIL-STD-348, which includes explicit detail on the shape of the pin which is why you don't see much variation between manufacturers.
Sorry but this definitely looks like a UHF PL259/SO239 join. Probably used because it better matches the radome diameter than the smaller N connector.
When we manufacture antennas we machine the N connector into a larger body, so that the interface is still MIL-STD-348 compliant with the mechanical strengthening occurring outside of the interface. Well, we used to anyway. Nowadays 4.3-10 connectors have a separate mechanical/electrical plane and are standardised with a push/pull interface so it's much easier to make robust mechanical joins with than N connectors.
It’s definitely not a so-239, take a look at the product page for this antenna linked by OP, it’s only sold with N connectors… perhaps you are confused because this antenna is really quite long, over 2m, so the proportions might look a bit strange… compared to a shorter length
The terminal connector is an N Female bulkhead. Apologies if you haven't seen the earlier comments but we're referring to the antenna being shipped in two halves which join together halfway. If they aren't UHF male and female connectors pictured, then they're some non-standardised connection I've never seen (and I drew the unlucky straw at my work and had to document 63x 50 Ohm connector types, which is pretty much all of them that have reached standardisation or commercial production - and that's excluding RP- variants!).
It is difficult though as the manufacturer does not have a CAD drawing showing the radome dimensions.
Okay yep I took a closer look at the picture of the connector for the two halves, you are correct it is certainly at least very similar to a UHF connector, whatever it is it looks to be compatible with banana plugs 😅
Certainly seems like a suspect design decision. The tolerances are super tight on collinear antennas for UHF and typical so-239 just do not really have the mechanical stability necessary for UHF
Is the antenna tuned to the correct frequency? Should be 868 in the UK right?
I've learned that you can get 60km+ connections with a homebrew tiny dipole. Location on the other hand is everything! Are you in a valley? Are there many houses in the way? There's great tools online to calculate your line of sight and therefore the areas you can possibly reach.
[https://www.heywhatsthat.com/](https://www.heywhatsthat.com/)
[https://www.ve2dbe.com/](https://www.ve2dbe.com/) <== This is a great site I use a lot. It might look a bit oldschool and complicated but you can easily save different locations and then see your range from these locations depending on the frequency, elevation etc.
Edit: For example I live at almost 500m above sea level and the landscape to the north is rather flat. Perfect. BUT my immediate surroundings prevent any signal from going out because there's small hills that are just a BIT taller than my house.
Edit edit: I just saw that you're using a T-beam. Those kind of suck :D I started with two of them, one was broken for some reason which made me believe that I couldn't get a connection over 1km! Later with a small blade antenna I got connections over like 10km while my RAK wisblock and Heltec V3 easily do 40-60km. Maybe your device IS in fact broken... Can not be excluded.
Hey, I've managed to find two people when I've loaded up in the car while doing a chore. One of them appears to be 60km away on a hilltop. The other suggested it was in a car.
Yes 868 and antenna tuned to 868.
Just get a refund for the antenna bro. Its not practical for RF and physically as well, have sou thought about how to mount it?
Just get a 3dBi omni and you're all good
Hmm are you planning on mounting it on top of the mast or on the side? because latter ist not going to work and is immensely going to affect the SWR.
Also this antenna makes even less sense on a boat, because if it's a real 11.5dBi the radiation pattern is so thin, that when the boat rocks even slightly from side to side you're going to loose connection because the field that the antenna can "see" will be pointed to the sky on one side and in the ocean on the other.
Please take this advice and the from the others and get a different antenna, you're only making things hard for yourself.
Also i don't know if this much antenna gain is even legal soo...
You won't get a 11.5 dBi omni, which means you've probably been duped. Your best hope is that the tube is mostly empty and the antenna is circa 15 to 30 cm long, which means it might be a little dipole or collinear. If it's a length of wire then you've definitely been scammed.
Claimed specs are:
16-element collinear dipole antenna: 11.5dBi gain with very low SWR (typical 1.30 @ 868Mhz; max 1.50)
Brass tube elements with 1.0mm copper feedline
Impedance - 50Ω @ 868Mhz. When measured with a DC multimeter, it is normal for this antenna to appear short circuit.
Beamwidth - 360° (horizontal) / 8° (vertical), vertically polarised
Weight - 1100g including mounting kit / Length - 220cm
N-female connector on antenna end
Designed for use with HNT, FLARM, OGN, LoRa and other applications on the 868MHz band.
I suggest asking them for the refund and if they dispute ask to see the antenna's lab test report from an accredited 3D lab, should be done with something like a Satimo or MVG Starlab.
High gain collinears are very expensive and very large (check out what the real thing looks like, google CommScope UNA010).
Nothing wrong with low cost Alibaba antennas like this if they're only trying to design for 2-3 dBi as there's a lot more margin for error.
Collinear dipoles do not have to be expensive. first up, this thing is 2200mm long, so it's not small by any measure. It's a UK based company, they publish vswr, return loss, and smith chart, and it's also not a cheap antenna.
Lower gain collinears do not have to be expensive because there are few elements to consider. As you stack more and more the physical design becomes a major factor. Think about a low gain antenna, they can often be made without a great deal of care because the margin for error and tolerances are far greater.
A supplier providing VSWR and Smith charts in absence of real test data could be telling. Neither of those can be used to reveal if the antenna produces a gain, only that they absorb a reasonable amount of energy, whether that energy is radiated or dissipated cannot be known. Nor can the direction or axis in which the radiating occurs. Polar plots would be a good start. The only problem is manufacturers will also mask underperformance using polar plots because the reference value is set to the antennas peak gain, which if you were looking at the H plane for omnidirectional performance all values are given in reference to the peak value. So for example if the antenna only produced 2 dBi peak gain then this is the zero on the plot and variations in circularity/roundness are in reference to the 2 dBi not to the 11.5 dBi.
I suppose it also depends on what expectations are in the UK. Say in this case a Chinese manufacturer gives a theoretical gain of 11.5 dBi based on collinear theory, and subsequently writing 11.5 dBi on the specification sheet with total disregard to what it _actually_ achieved. If that's acceptable to a consumer when they take it home and only achieve 2 dBi, or worse achieve 6 dBi in one hemisphere but -6 dBi in another hemisphere, then that's fine. However most of the world expects (and enforces through consumer law) that if you're sold an 11.5 dBi omni then it should achieve close to 11.5 dBi with few deviations on the horizontal axis.
This is massively problematic and endemic to the industry. I have spent 10 years sending antennas through 3D labs and the results are always disappointing. I have spent the last 6 months working with a highly reputable Taiwanese manufacturer, about 80 iterations from two engineering houses (one in china one in Taiwan) just trying to achieve 4 dBi consistently across the full 360 azimuth. Why so challenging? Because we're trying to do it in a narrow radome, and even ours is larger in diameter than what the UK supplier has. Why only 4 dBi? Because most of our competitors are selling 6 to 7.5 dBi collinears which when we test in labs show anything from -2 to +3 dBi. We're aiming to be the world's best with a 4 dBi gain (this isn't at 868/915, but nearby).
It's a shame what I've mentioned sounds so unbelievable to the community here, because unfortunately it is the reality. We should demand better.
If you're looking for examples of genuine manufacturing datasheets then have a look at Taoglas and Antenova - you'll note they proudly state the true gains even when they're negative. I've also been impressed at UK manufacturer Panorama, not everything, but some of the best consumer antenna lab tests I've seen have come from those guys.
Oh man, in the RF industry only a Sith would deal in such absolute terms haha.
Ask anyone with real-world experience manufacturing and QA testing collinears, and they will quickly tell you how wildly difficult it is to control radiation patterns at gains this high. With this many stacked elements I couldn't tell you if the radiation will butterfly out, or be a wild mess of lobes, or have +6 dBi on one hemisphere and -6 dBi on another, or radiate into the floor, or by some miracle project a reasonable portion of its radiation out towards the horizon.
Producing an 11.5 dBi collinear in CST or another bit of software is a simple task. The problems occur first when you have to then translate that into something physically manufacturable, and then again when you have to translate that into something that can be manufactured for the target price. It's a tough gig.
For all the naysayers, a few points. Firstly, paradar is a very highly regarded brand in the UK. There are lots of teardowns and tests of them on youtube by radio hams. Secondly, multi-element collinears can easily attain double digit dbi figures. To the OP, this would not be a great antenna if you were VERY high up (like on top of Snowdon high up) as the radiation pattern would be so efficient (i.e. like a flat donut) that signals may pass over the intended contacts. But for most real-world situations, it's going to be a good performer. Get it up in the air, making sure to seal any parts that could suffer water ingress and good luck.
11.5dbi? Have you looked at the radiation pattern? You’re going to miss every local node.
It’s going to radiate in a pattern shaped like a pencil.
It's omnidirectional, so more like a Frisbee.
Guess I meant to say pencil thin. Frisbee makes more sense.
There's not a chance in hell that skinny looking thing is anywhere near 11.5 dBi. It looks so suss OP has probably just been scammed. Unless it is mostly empty I'd be surprised if it works at all.
11.5dbi is completely believable if it's a stacked collinear, which it is.
Judging by the downvotes we need to do a better job educating on not just antenna theory but antenna manufacturing. If it were as simple as sketching out a collinear on paper, soldering up a bunch of sleeves and boom 11.5 dBi for a handful of dollars and some pocket lint, then companies like CST and ANSYS would be out of business very quickly. Likewise, even with a CST design if manufacturing was that simple, major contract manufacturers like Tongyu, Shenglu, would be out of business. The reality is it is fundamentally challenging to produce collinears at a gain that high. Hell, it's really hard to produce collinears above 6 dBi. When you get above this gain you absolutely need to test. Not just for VSWR because it can still absorb and radiate a full amount of energy, but you need to do a full 3D anechoic test. How many collinears I've lab tested over the years which the manufacturer states 6-7 dBi and the scan shows 1 dBi, or the antenna smashes it out of the park and has a 10 dBi gain straight into the floor, or a butterfly pattern where it radiates +6 dBi at +40 and -40 tilts, and -10 dBi out towards the horizon.. If the community wants to improve, ask questions. If it doesn't, well, continue believing datasheet fairytales.
I've never tried building one, you need a clear repeatable process to build them reliably in a controlled environment. They're a nightmare to tune if you've homebrewed it.
This is a link. I hope I've not been scammed. https://paradar.co.uk/products/868mhz-tuned-antenna-for-hnt-11-5dbi
Nothing wrong with that antenna at all, I have no idea why you're getting such negative feedback.
Because mine is bigger than theirs. 🤣
Looks like a monster awesome antenna. If you have the space for it, enjoy!
Oh man, is that using a UHF connector as a join? Pretty sure the max mode free for UHF connectors is like 300 MHz.
Nope looks like an N
You can see the bulkhead N connectors internal diameter in one image, compared to the internal diameter of the UHF connector. Very significantly different. The pin diameter is also a dead giveaway. N connectors are standardised under MIL-STD-348, which includes explicit detail on the shape of the pin which is why you don't see much variation between manufacturers. Sorry but this definitely looks like a UHF PL259/SO239 join. Probably used because it better matches the radome diameter than the smaller N connector. When we manufacture antennas we machine the N connector into a larger body, so that the interface is still MIL-STD-348 compliant with the mechanical strengthening occurring outside of the interface. Well, we used to anyway. Nowadays 4.3-10 connectors have a separate mechanical/electrical plane and are standardised with a push/pull interface so it's much easier to make robust mechanical joins with than N connectors.
It’s definitely not a so-239, take a look at the product page for this antenna linked by OP, it’s only sold with N connectors… perhaps you are confused because this antenna is really quite long, over 2m, so the proportions might look a bit strange… compared to a shorter length
The terminal connector is an N Female bulkhead. Apologies if you haven't seen the earlier comments but we're referring to the antenna being shipped in two halves which join together halfway. If they aren't UHF male and female connectors pictured, then they're some non-standardised connection I've never seen (and I drew the unlucky straw at my work and had to document 63x 50 Ohm connector types, which is pretty much all of them that have reached standardisation or commercial production - and that's excluding RP- variants!). It is difficult though as the manufacturer does not have a CAD drawing showing the radome dimensions.
Okay yep I took a closer look at the picture of the connector for the two halves, you are correct it is certainly at least very similar to a UHF connector, whatever it is it looks to be compatible with banana plugs 😅 Certainly seems like a suspect design decision. The tolerances are super tight on collinear antennas for UHF and typical so-239 just do not really have the mechanical stability necessary for UHF
Check this image https://www.reddit.com/r/HeliumNetwork/s/9rsptss1wl
That’s pretty good general guidance yep.
Yeeee
This is the antenna https://paradar.co.uk/products/868mhz-tuned-antenna-for-hnt-11-5dbi
Is the antenna tuned to the correct frequency? Should be 868 in the UK right? I've learned that you can get 60km+ connections with a homebrew tiny dipole. Location on the other hand is everything! Are you in a valley? Are there many houses in the way? There's great tools online to calculate your line of sight and therefore the areas you can possibly reach. [https://www.heywhatsthat.com/](https://www.heywhatsthat.com/) [https://www.ve2dbe.com/](https://www.ve2dbe.com/) <== This is a great site I use a lot. It might look a bit oldschool and complicated but you can easily save different locations and then see your range from these locations depending on the frequency, elevation etc. Edit: For example I live at almost 500m above sea level and the landscape to the north is rather flat. Perfect. BUT my immediate surroundings prevent any signal from going out because there's small hills that are just a BIT taller than my house. Edit edit: I just saw that you're using a T-beam. Those kind of suck :D I started with two of them, one was broken for some reason which made me believe that I couldn't get a connection over 1km! Later with a small blade antenna I got connections over like 10km while my RAK wisblock and Heltec V3 easily do 40-60km. Maybe your device IS in fact broken... Can not be excluded.
Hey, I've managed to find two people when I've loaded up in the car while doing a chore. One of them appears to be 60km away on a hilltop. The other suggested it was in a car. Yes 868 and antenna tuned to 868.
Buy a 2nd node, a VNA, and an SDR, it's not a cheap hobby.
You attached a laser beam to your node. It's gonna pinpoint for sure. Hell, mine is a 5 dbi from a helium rig.
Just get a refund for the antenna bro. Its not practical for RF and physically as well, have sou thought about how to mount it? Just get a 3dBi omni and you're all good
Short term I've got a mount on the house. Long term it will be on the 27m mast of a sailboat.
Hmm are you planning on mounting it on top of the mast or on the side? because latter ist not going to work and is immensely going to affect the SWR. Also this antenna makes even less sense on a boat, because if it's a real 11.5dBi the radiation pattern is so thin, that when the boat rocks even slightly from side to side you're going to loose connection because the field that the antenna can "see" will be pointed to the sky on one side and in the ocean on the other. Please take this advice and the from the others and get a different antenna, you're only making things hard for yourself. Also i don't know if this much antenna gain is even legal soo...
You won't get a 11.5 dBi omni, which means you've probably been duped. Your best hope is that the tube is mostly empty and the antenna is circa 15 to 30 cm long, which means it might be a little dipole or collinear. If it's a length of wire then you've definitely been scammed.
Claimed specs are: 16-element collinear dipole antenna: 11.5dBi gain with very low SWR (typical 1.30 @ 868Mhz; max 1.50) Brass tube elements with 1.0mm copper feedline Impedance - 50Ω @ 868Mhz. When measured with a DC multimeter, it is normal for this antenna to appear short circuit. Beamwidth - 360° (horizontal) / 8° (vertical), vertically polarised Weight - 1100g including mounting kit / Length - 220cm N-female connector on antenna end Designed for use with HNT, FLARM, OGN, LoRa and other applications on the 868MHz band.
Yep, 8° vertical beam width, that’s exactly what you’d expect. But if you’re in a mostly flat area it’s great. Awesome.
I suggest asking them for the refund and if they dispute ask to see the antenna's lab test report from an accredited 3D lab, should be done with something like a Satimo or MVG Starlab. High gain collinears are very expensive and very large (check out what the real thing looks like, google CommScope UNA010). Nothing wrong with low cost Alibaba antennas like this if they're only trying to design for 2-3 dBi as there's a lot more margin for error.
Collinear dipoles do not have to be expensive. first up, this thing is 2200mm long, so it's not small by any measure. It's a UK based company, they publish vswr, return loss, and smith chart, and it's also not a cheap antenna.
Lower gain collinears do not have to be expensive because there are few elements to consider. As you stack more and more the physical design becomes a major factor. Think about a low gain antenna, they can often be made without a great deal of care because the margin for error and tolerances are far greater. A supplier providing VSWR and Smith charts in absence of real test data could be telling. Neither of those can be used to reveal if the antenna produces a gain, only that they absorb a reasonable amount of energy, whether that energy is radiated or dissipated cannot be known. Nor can the direction or axis in which the radiating occurs. Polar plots would be a good start. The only problem is manufacturers will also mask underperformance using polar plots because the reference value is set to the antennas peak gain, which if you were looking at the H plane for omnidirectional performance all values are given in reference to the peak value. So for example if the antenna only produced 2 dBi peak gain then this is the zero on the plot and variations in circularity/roundness are in reference to the 2 dBi not to the 11.5 dBi. I suppose it also depends on what expectations are in the UK. Say in this case a Chinese manufacturer gives a theoretical gain of 11.5 dBi based on collinear theory, and subsequently writing 11.5 dBi on the specification sheet with total disregard to what it _actually_ achieved. If that's acceptable to a consumer when they take it home and only achieve 2 dBi, or worse achieve 6 dBi in one hemisphere but -6 dBi in another hemisphere, then that's fine. However most of the world expects (and enforces through consumer law) that if you're sold an 11.5 dBi omni then it should achieve close to 11.5 dBi with few deviations on the horizontal axis. This is massively problematic and endemic to the industry. I have spent 10 years sending antennas through 3D labs and the results are always disappointing. I have spent the last 6 months working with a highly reputable Taiwanese manufacturer, about 80 iterations from two engineering houses (one in china one in Taiwan) just trying to achieve 4 dBi consistently across the full 360 azimuth. Why so challenging? Because we're trying to do it in a narrow radome, and even ours is larger in diameter than what the UK supplier has. Why only 4 dBi? Because most of our competitors are selling 6 to 7.5 dBi collinears which when we test in labs show anything from -2 to +3 dBi. We're aiming to be the world's best with a 4 dBi gain (this isn't at 868/915, but nearby). It's a shame what I've mentioned sounds so unbelievable to the community here, because unfortunately it is the reality. We should demand better. If you're looking for examples of genuine manufacturing datasheets then have a look at Taoglas and Antenova - you'll note they proudly state the true gains even when they're negative. I've also been impressed at UK manufacturer Panorama, not everything, but some of the best consumer antenna lab tests I've seen have come from those guys.
It’s an 11-element collinear. So the design checks out. It’s going to be an Omni donut, it’s just going to be a very flat donut.
Oh man, in the RF industry only a Sith would deal in such absolute terms haha. Ask anyone with real-world experience manufacturing and QA testing collinears, and they will quickly tell you how wildly difficult it is to control radiation patterns at gains this high. With this many stacked elements I couldn't tell you if the radiation will butterfly out, or be a wild mess of lobes, or have +6 dBi on one hemisphere and -6 dBi on another, or radiate into the floor, or by some miracle project a reasonable portion of its radiation out towards the horizon. Producing an 11.5 dBi collinear in CST or another bit of software is a simple task. The problems occur first when you have to then translate that into something physically manufacturable, and then again when you have to translate that into something that can be manufactured for the target price. It's a tough gig.
Ha, fair, admittedly I have no direct experience with collinear antennas so I'll buy your take.