honestly.... you are the kind of god this hobby needs. i am very thankfully for sharing your thoughts and discoveries with us. i love your work, i love your antennas and i like you as a person. hope all the best to you and stay crazy!
Thank you. I do my best, but unfortunately the turnover rate in FPV is getting faster and faster. Thus the tech people are looking for is buried under marketing.
As an Amateur radio Operator for the past 29 years this is Yagi 101. You should learn this at the Technician level. Nice training course for those who have no experience. Now if you could get people to become legal flying 1.3 gear and take a simple easy to pass technician license. Side note. I have invested lots of money into your antennas and like your products. We have been testing antennas for past 35 years at Central States VHF Society Conferences around the USA. Love the range test days where folks test out antenna designs. Keep at it and keep teaching!
The legality thing has been a losing battle over the years and I gave up trying to get people to get their HAM license years ago. Instead, I focus on getting people interested in the tech and hope they decide to pursue the licensing.
JD Dupuy I passed my technician exam before I put my first FPV bird up in 2014... but I really should pursue the next level up. A lot of this is still very confusing even with what I studied for the test and what I’ve learned over the last few years.
JD Dupuy In fact, even tho I took my tech exam exclusively for using HAM FPV freqs, I always say I wanted to but a radio and start transmitting, but never did. I live in the mountains now so it would probably be a good idea to get on that.
A simple parasitic reflector ... as developed by Uda / Yagi (two colleagues at Tohoku Imperial University circa 1926). The actual physical length of the parasitic reflector is important as well. In GENERAL, a reflector 5% longer than 1/2L F (1/2 wavelength of fundamental frequency length) will attain the desired result. By adding directional elements in FRONT of the array (about 5% shorter) starting at about 1/4 wavelength ahead of the driven element, you can further increase gain and directivity. As one who has built many Amateur radio antennas (and still have my original 4 element tri-band Yagi up over my house), I can confirm this is not magic or rocket science ... just the application of known antenna development. For UHF & SHF frequencies, these antennas can still be manageably small and useful. At HF frequencies, the antennas get very large ... my 4 element tri-band Yagi has a "footprint" on the ground nearly as large as the roof of my house. At UHF/SHF frequencies, dimensions become very critical (compared with HF frequencies). Good demonstration. BTW, still waiting for a response from you to a question I posed on the VAS website (contact email) regarding optimizing my FPV signal @ 5.8ghz. Happy New Year & Cheers.
Yes, what u have made is a reflector for the driven element ( no offence meant but just basic antenna design). I like the demonstration but I wonder how many quads will be lost because they missed the part about only flying in front of the antenna. Possibly it could inspire a new antenna design👍. Keep it up, good stuff
Thanks for this post Bill. I was just going to ask for the equations so that I could do the math myself. And I was wondering too about forward elements. I use the CF micro module, so it’s kind of like QRP, I like the extra challenge of lower power. I liked to see what worked on the VNA and I like to run the math myself for my region, 915mhz, so thanks to you both!
@ Bill Somrak ok for adding extra 5% for a reflector (of 1/2F) but how about the position? Is there any general rule of thumb, I want to make antenna for terrestrial TV (not sure exact frequency now but something from 480-800Mhz)
Welcome to the world of physics Mr Crazy....its funny to see, HOW u find this. U found well known antenna knowledge....and for all the forum pppl, u are a god. Sorry, thats only physics
I gave this hack a try. As a result of the Diamond antenna modification as demonstrated in the video, VSWR is significantly worse now. Without the mod it was almost perfect at better than 1:1.2 but shows at 1:2.5 now. There will be a gain in range due to added directivity, but 18% of the transmission power is reflected back into the transmitter, not exactly what we want.
I was reading 1.8:1 on my Agilent Field Fox VNA. In order to read properly you must use an extension cable to move the antenna away from objects and then re-calibrate the analyzer to that added cable. Indeed there is an increase in VSWR. However, the gain in range is significantly greater. You can mitigate this by cutting the wire down some. This will reduce your forward gain as well, but put your SWR closer to the value you want.
@@CAGreve1231 Thank you for the clarification. My main concern is the Crossfire transmitter at high output power settings during long range flights. Can the reflected power do any damage?
@@VodooFeed - In extreme cases it can do damage. However, I wouldn't be concerned with this mod. Remember that SWR is more affected when people lay their transmitters on the ground or in their laps when sitting down.
Alex, Obviously that's a very neat hack. I would not want to give up the proximity signal strength. so why don't you make one of those that sits tight against the post when you don't need it and then you just push a little mechanical switch that extends the arms out to both sides for when you're at long-range then when you launch you can leave it tucked into the post and not making any difference in your proximity stuff. And as soon as you get to long-range you just flipped a little mechanical switch that pushes the arms out to the proper space.so again when you're not using it it would tuck in next to the post and not make any RF difference. But when you are long-range you just push a little lever that extends the arms out and does that parasitic reflection.
3D print files are ready: www.thingiverse.com/thing:3324358 cdn.thingiverse.com/renders/ce/12/67/cb/37/9582e44cf30b6e6b1efb163b604564ed_preview_featured.jpg
so next question - the diamond antenna is also available for the EU version of crossfire which works with 868Mhz, could you calculate for that also the distance and cable-lengt for this mod ?
Nice hack. Thanks for sharing. What I am wondering is if my Taranis X9D radio, if the Chrome plated bar at the back of the radio, as well as the add on swiveling metal kickstand that I've added are somehow also affecting the shape of the Diamond's emissions. I suspect so, because your addition of a simple length of wire has an impact on the antenna, perhaps also the "hardware" which is on the controller might also be causing some issues. Since you have the test equipment, would love to see you test a typical kitted up controller as well, to see how these metal components impact the signal.
Hi. This is very informative video. please tell me which is front side and which is back side of the TBS diamond antenna? how to mount in our taranis the front facing our quad or to our self? pls suggest for the best and optimum reception. thanks
What would happen if you cut a wire and connected the two ends to make roughy an oval shape and attach it behind the antenna? So a similar shape as the diamond. Would that help get the signal behind you as well or would cancel out?
Interesting video. What frequency are these diamond antennas or indeed the Immortal T antennas tuned to? I ask as if it's 915Mhz then are they less than ideal for use in Russia or the EU where we use 868Mhz? Thanks. Great channel btw. 😄
The bandwidth of the Immortal T is much narrower than the diamond and thus, without testing it, I cannot make a recommendation to do it. The Diamond antennas work well with both 868 and 915MHz frequencies. However, to answer your question, the distance for the Immortal T and the diamond would be the same and have similar gains. However, the Immortal T might have significantly higher VSWR which could damage your transmitter.
@@CAGreve1231 Excellent response thanks. I was going to use the diamond as my primary controller TX. I just ordered the Crossfire nano diversity and two Immortal T v2 antennas for my quad so I can have one each side in the vertical position. But I watched a video just now that says that the best way is to not use the Immortal T's and take the soft dipoles you get with the nano diversity module and trim off 7.5mm. Apparently this will tune them for 868Mhz Also the video said if I use plastic tubing and or heatshrink this will also affect the tune meaning I may need to cut a further 0.5mm off. Does this sound advisable?
@@changeagent228 - Can I recommend not trimming the antennas that come with the receiver. trimming the ends off moves them to a HIGHER frequency, not a lower one. Using a coating will certainly increase the effective length (and thus reduces the center frequency). However, I would think the effect should be rather small.
@@CAGreve1231 You are absolutely right that makes sense. I will just test them stock. On the Immortal T v2 stiff plastic version which is the top and bottom of the dipole because there are no markings to indicate top or bottom? I can see the TBS logo on one side at the middle so I can get them matched on each side of my camera mount but just not sure which side is the ground plane which I'm guessing should be pointing down given the diamond antenna on my TX will be oriantated correctly vertically like the lobe diagram on the antenna shows.
so does that mean when the diamond is mounted horizontally on a full crossfire, using a taranis radio, the taranis radio handle gives some reflection too ! ? even if the wrong dimensions
I'm going to design a 3D printed part for that (hooking up to the lower bar of the diamond, so you can bend the RG405 as you wish, but the parasitic would stay parallel to the diamond)
@@CAGreve1231 no problem, will do. I'm thinking about a forum for fpv mods only. any ideas where to set up? ( I have more custom things to put there for everyone)
@@CAGreve1231 we must shorten the distance for QX7S users, the chrome handle is colliding with the parasitic element (if the diamond is vertical). For QX7S the distance would reduce to 38,5mm. could you check that problem on the X9D please?
this is amazing! well done. very interesting. is the non moded diamond less effective than the stock immortal T shape for radiating aside and behind me? cheers
@@CAGreve1231 hey thanks Alex. I spent hours as a kid putting tin foil on the underside of an umbrella and connecting it to a radio to hear aliens, satelites or radio broadcasts from far away, like Russia or something 😅 i had no idea what i was doing and it didn't work. wishing i had you as a friend back then! LOL Keep em flyin
As there is only one diamond for both regions, do I use the same dimensions for 868 MHz, or is it better to lengthen the reflector accordingly (16,1 cm)?
Most likely not. The length is very specific. If it isn't exactly correct, then the handle will have minimal effect (which is whatmost people observe).
Three reasons: 1. Size - This makes the antenna larger 2. Directionality - Most people prefer an omni-directional antenna to a directional one 3. Simplicity - A single element is much simpler than multiple parts
Say you use the True mox 915mhz would you even use this antenna anymore? TBS Diamond is great for being used as an antenna on the quad side receiver try it :) LONG RANGE
Alex, great tip, any info how ground (earth) affects the antenna performance? Does it act similar to Moxon (gains drops with proximity of ground/earth)?
Will this cause some issues flying far and low to the ground, or will it retain consistent coverage at different altitudes like with the unmodified diamond antenna?
You should see an improvement in signal at all altitudes below 55 degrees with this mod. If you azimuth exceeds 55 degrees from your location, you would be better off without the mod.
Every time you adjusted that straight wire or rod or whatever, I noticed that you stepped back. How far back are you stepping when you do that? And would this make any difference in real world circumstances? Due to you're holding the transmitter close to your body anyways. Because due to these observations (of mine just now), it seems to me as if I should either fabricate some kind of mount with coaxial extension on my transmitter 'carry bar' (or whatever the hell that thing is), or construct a stand alone mount w/coaxial extension, for my transmitter antenna. In order to not be seriously degrading my transmitter's signal with just normal usage proximity.
I am glad someone caught that! The truth is the amount I step back is simply an empirical value. In other words, I back up until the effect of my body on the measurement is negligible. There really is no set distance.
Alex Greve Any object that comes close to the antenna is going to detune it. So if you put a reflector on the antenna as you did and then stand away from it you’re going to get a certain result. But then, when you take the antenna off and put it on the radio with someone holding the radio the measurements are going to be different. So, to make this practical for FPV use you should make a part 2 and show the results of the antenna on the radio while it is being held. Then re-tune the antenna for max results while being held 👍
@@53roger - As a general rule: anything behind the reflector is minimal. The reason for this is because the energy is being re-directed rather than making it back to the pilot or the radio. Thus, there would be little, if any change to any of the dimensions.
It's not the size that matters, it's how you use it! Sorry, couldn't resist. Same antenna, just different frequency. 2.4GHz has a shorter wavelength so it is smaller.
@@CAGreve1231 HI, my TBS Crossfire Micro TX is arriving soon. I'm a little confused with description on the TBS Diamond antenna - www.team-blacksheep.com/products/prod:diamond_antenna It says "A slightly-directional antenna for best signal penetration". Does it mean it's still omni-directional?
Would this extra element fix the forward null spot on the 433Mhz diamond antennas? Can you do a quick how to video for us 70cm guys? Or at least some reflector wire lengths to start?
Alex Greve you and I had this discussion about the null spot on the 433 diamond a few weeks ago. Remember I told you when I held the diamond antenna to the side my RSSI increased and when pointed forward it decreased a lot. I was in extreme conditions and distance for the environment. You said it was because of the part in the middle of the antenna. The bent part is a micro strip. It was to balance the antenna.
@@Hyprmtr - A null is "0" or no signal. When mounted near the ground, the Diamond lends more of its transmitting energy to the sides rather than straight forward which is the phenomenon you are seeing. This is caused by the geometry and the balun in the center. The difference in strength is about 1.5db or so.
Alex Greve would this modification help push the center lobe to be more uniform compared to the side lobes? I already got mine modded. I just need some good weather to try it.
I know you probably have stuff going on, but it would be greatly appreciated if you did a review of Crossfire antennas and how placement affects performance. Just got the large module with the immortal T and I get RSSI and LQ warnings at 500m with two vertically mounted antennas... Extremely frustrating to say the least.
Your problem isn't the RX antenna. The Immortal T signal is deflected by the ground causing destructive interference. This is the precise problem the diamond was designed to fix.
@@CAGreve1231 So I did a good amount of testing. It's important to note that my antenna is mounted vertically with the same tilt as my FPV camera, and one full half of the the Immortal T is above the GoPro and the entire antenna is isolated by 3/4 from any material. Now here come's the weird part: Even with flipping the antenna to find the "active element" I still experienced this: As low as 65 LQ on 2 Watts heading out, and 99 LQ at 25mw headed back. (this is on dynamic power recorded live). This was the same with either position. The only other thing I can think of is my 5.8 antenna. It's a Lumeniier LR Axii that sticks out to the same height as the Immortal T above the quad. It is mounted 3 inches away (diagonally) from the T and is transmitting 5.8Ghz at 800mw. Do know what could be the source of this LQ/RSSI problem?
@@nige5572 - That's an unusual problem, but you have a good installation. The Crossfire should never hit 2 Watts running a quad. I can certainly help you troubleshoot the problem, but ti is best done through Email. Send me some photos of your vehicle and have someone take a picture of you flying and I will see what I can do.
This is not an easy question to answer. In general, horizonatally polarized waves travel better at low altitudes. However, the ground will change the polarization to have vertical components to the wave as well. Thus, horizontal is technically better so long as you don't fly into a null.
@@philaell sure. Use the rssi feature. Set the quad some distance away, set the r9m to range test mode, vary the distance and work out what gives the best rssi.
@@nohandle1 I actually tried that with my diy dipole on my r9m. Rssi seemed to change a few digits but I couldn't verify if it was me moving the tx or the wire reflector moving. I'll have to test with the tx somewhere stable.
Unfortunately this is a tall order simply because the transmitter is sending the signal and not receiving it. If the transmitter is allowed to receive, then we could certainly do this. Typically this is done by beam forming.
I was told the diamond antenna doesn't have any dead spots(at least thats what the person stated), so does that mean if I do this mod I won't be able to fly behind myself(I do that now with no issues) and have to worry about dead spots?
The diamond has very small dead spots that don't really have a large affect on RSSI or LQ. If you do this mod you will basically have no effective range behind you as you are utilizing a parasitic reflector to reflect the signal output in one direction. Look at his FPV antennas video if you want a visualization. The diamond (equivalent of an omni) was just turned into a directional antenna.
@@DavidHanniganJr - It is. You can pick one up used for about $10,000 or so which puts it well outside of DIYer territory. However, you can use 2X RFExplorers and create a makeshift version of this machine for about $500.
Literally any metallic wire will work for this. Even a steel TIG welding wire will work. Just use whatever is convenient for you and it will work well.
@@CAGreve1231 obviously this is amazing I just didn't know if that could possibly both increase directional signal and also possibly retain higher DBI omnidirectional too? Thanks again
@@vasprofessional1094 ty, that's why your the man, the thee turn helical has been my go too since the day I got it. All time fav for my range atm. Ty, again n always looking for a new VAS ANTENNAS worth every penny!! 😎
serval FPV It doesn’t matter how you mount the antenna. What natters is when flying, the antenna on the tx is point toward the quad like he is showing in the vid
@@53roger obviously the antenna has to point to the quad im hardly going to hide it... but i want to get the optimum range so should it be tx & rx horizontal / vertical 1 each way theres surely a correct and wrong way to set it up !
serval FPV to get the maximum signal the tx and the rx antennae need to be situated in the same ‘plane’. So generally speaking, the antenna on the quad and how it’s mounted determines whether it is horizontal or vertically polarized. For example, if you used a TBS immortal T antenna mounted vertically on your quad then you would want your radio transmitter antenna mounted vertically and vice versa hope this helps
i just checked it, the dipole became a yagi right? question is, does the additional elements have wire connections on the main antenna? i don't see any from the pictures
@@don0219 - This is as simple as it looks. Yes, I made a simple 2 element yagi. No electrical connections. It is just a 6" section of wire 1-5/8" behind the antenna. There are a few 3D printable parts on thingiverse so you don't have to ghetto-rig it with electrical tape like I did.
Great video. I will buy the diamond antenna. Crossfire fail-safes like crazy at less than 100m distance and I have done everything TBS has told me to do. Do you think the diamond antenna will solve this problem or is it a firmware issue? I use v2.41 on a big crossfire 500mW static power.
Antenna is not your problem unless it has some factory defect, look somewhere else. Unsoldered/disconnected pigtails inside the module has been reported
@@slavikarg Thanks, yes loose pigtails has been a problem for many. Tbs told me to check that on the the first crossfire micro transmitter. Then they sent me a new micro transmitter and they told me to check the pigtail again. Then I asked them to send a big crossfire, same problem. And I have two nano receivers, same problems. Firmware 2.24 was terrible and I updated to 2.41 which I think is better but I still get failsafe and I lose control here and there for half a second and it feels really wrong.
Failsafes at 100m tells me something is very wrong and you need to find what is causing the issue. This mod would only be a band-aid fix. I would suggest investigating the issue further before trying mods like this to fix it.
@@vasprofessional1094 Thanks Alex, but after Tbs keept sending me new transmitter modules and I sent them photos of my installations of two different quads, I'm running low on ideas what to do. I have done everything they suggested and sometimes it can work for a while and then there is a failsafe or a second of lost control. So for me, even if I'm an engineer and I have a reasonable good experience trubleshooting booth hardware and software, if someone tell me to stand on one leg when I fly, I will try it...
@@Siamect - This sounds like a receiver issue to me. Usually range loss is in the receiver. The u.fl connector isn't very good for FPV use despite what people want. That would be the place I look.
Hacking it like that will give you range but also some pesky random lobes. Have fun pointing it bvlos :p Make things right, rigid, good materials like extruded aluminium pipe, a solid boom, tight reflector mount. Tape won't do it very well for very long.
Aluminum pipes and such will cause side-lobes. Tape won't. The idea behind this was to inspire some people to design some 3D printed mounts. Within 5 hours of posting the video, pixel comet designed a 3D printable TPU mount.
honestly.... you are the kind of god this hobby needs. i am very thankfully for sharing your thoughts and discoveries with us. i love your work, i love your antennas and i like you as a person. hope all the best to you and stay crazy!
You actually used a VNA to showcase a yagi-uda reflector beam. Other people would just eyeball that. Mad respect.
Yawplomacy. Alex you are FPV innovator of the year. Thank u for your service sir.
More decade.... almost every antenna we have had came from this mans work...
I vote ibcrazy to take over from Sir Bruce, when is his no longer able to educate us.
Thank you. I do my best, but unfortunately the turnover rate in FPV is getting faster and faster. Thus the tech people are looking for is buried under marketing.
@@vasprofessional1094 common struggles and i do understand. Just note that you are valued and have taught many.
Mind blown
As an Amateur radio Operator for the past 29 years this is Yagi 101. You should learn this at the Technician level. Nice training course for those who have no experience. Now if you could get people to become legal flying 1.3 gear and take a simple easy to pass technician license. Side note. I have invested lots of money into your antennas and like your products. We have been testing antennas for past 35 years at Central States VHF Society Conferences around the USA. Love the range test days where folks test out antenna designs. Keep at it and keep teaching!
The legality thing has been a losing battle over the years and I gave up trying to get people to get their HAM license years ago. Instead, I focus on getting people interested in the tech and hope they decide to pursue the licensing.
JD Dupuy I passed my technician exam before I put my first FPV bird up in 2014... but I really should pursue the next level up. A lot of this is still very confusing even with what I studied for the test and what I’ve learned over the last few years.
JD Dupuy In fact, even tho I took my tech exam exclusively for using HAM FPV freqs, I always say I wanted to but a radio and start transmitting, but never did. I live in the mountains now so it would probably be a good idea to get on that.
Alex have you ever taken your test? You do not show up on the FCC Data Base.
A simple parasitic reflector ... as developed by Uda / Yagi (two colleagues at Tohoku Imperial University circa 1926). The actual physical length of the parasitic reflector is important as well. In GENERAL, a reflector 5% longer than 1/2L F (1/2 wavelength of fundamental frequency length) will attain the desired result. By adding directional elements in FRONT of the array (about 5% shorter) starting at about 1/4 wavelength ahead of the driven element, you can further increase gain and directivity. As one who has built many Amateur radio antennas (and still have my original 4 element tri-band Yagi up over my house), I can confirm this is not magic or rocket science ... just the application of known antenna development. For UHF & SHF frequencies, these antennas can still be manageably small and useful. At HF frequencies, the antennas get very large ... my 4 element tri-band Yagi has a "footprint" on the ground nearly as large as the roof of my house. At UHF/SHF frequencies, dimensions become very critical (compared with HF frequencies). Good demonstration. BTW, still waiting for a response from you to a question I posed on the VAS website (contact email) regarding optimizing my FPV signal @ 5.8ghz. Happy New Year & Cheers.
I've been having website issues. Best to just EMail me directly. videoaerial at gmail gets through a lot better.
Come on champ. As you said, "Its not rocket science". Figure out your 5.8 issues on your own.
Yes, what u have made is a reflector for the driven element ( no offence meant but just basic antenna design). I like the demonstration but I wonder how many quads will be lost because they missed the part about only flying in front of the antenna. Possibly it could inspire a new antenna design👍. Keep it up, good stuff
Thanks for this post Bill. I was just going to ask for the equations so that I could do the math myself. And I was wondering too about forward elements. I use the CF micro module, so it’s kind of like QRP, I like the extra challenge of lower power.
I liked to see what worked on the VNA and I like to run the math myself for my region, 915mhz, so thanks to you both!
@ Bill Somrak
ok for adding extra 5% for a reflector (of 1/2F) but how about the position? Is there any general rule of thumb, I want to make antenna for terrestrial TV (not sure exact frequency now but something from 480-800Mhz)
Awesome hack...thanks for your time on this!
Welcome to the world of physics Mr Crazy....its funny to see, HOW u find this. U found well known antenna knowledge....and for all the forum pppl, u are a god. Sorry, thats only physics
Of course it is only physics. I am simply showing the way it works. You know you are talking to a guy who has 6 patents on antenna tech, right?
Great video. Keep making awesome antennas!
Excellent... Great video to close out 2018....
Wishing a Happy and prosperous New Year to you and yours Alex.
Ty for this bro, as if it wasent AMAZING ENOUGH.. Thank God for you n Trappy!
I gave this hack a try. As a result of the Diamond antenna modification as demonstrated in the video, VSWR is significantly worse now. Without the mod it was almost perfect at better than 1:1.2 but shows at 1:2.5 now. There will be a gain in range due to added directivity, but 18% of the transmission power is reflected back into the transmitter, not exactly what we want.
I was reading 1.8:1 on my Agilent Field Fox VNA. In order to read properly you must use an extension cable to move the antenna away from objects and then re-calibrate the analyzer to that added cable.
Indeed there is an increase in VSWR. However, the gain in range is significantly greater. You can mitigate this by cutting the wire down some. This will reduce your forward gain as well, but put your SWR closer to the value you want.
@@CAGreve1231 Thank you for the clarification. My main concern is the Crossfire transmitter at high output power settings during long range flights. Can the reflected power do any damage?
@@VodooFeed - In extreme cases it can do damage. However, I wouldn't be concerned with this mod. Remember that SWR is more affected when people lay their transmitters on the ground or in their laps when sitting down.
I wish i knew as much as you alex, im thinking about taking up rf engineering because i find it so interesting and amazing how signals work.
It is a great field to go into. Radio controls everything we do and good RF people are hard to find.
Alex,
Obviously that's a very neat hack. I would not want to give up the proximity signal strength. so why don't you make one of those that sits tight against the post when you don't need it and then you just push a little mechanical switch that extends the arms out to both sides for when you're at long-range then when you launch you can leave it tucked into the post and not making any difference in your proximity stuff. And as soon as you get to long-range you just flipped a little mechanical switch that pushes the arms out to the proper space.so again when you're not using it it would tuck in next to the post and not make any RF difference. But when you are long-range you just push a little lever that extends the arms out and does that parasitic reflection.
Actually you make this and it's simple elegant and works well and every single person will have it on their dimond antenna.
@@fotalimark There are tons of snap-on spacers on thingiverse for this very purpose.
He actually was talking about the function of the Shapeshifter antenna before he realized that it already existed ;)
3D print files are ready: www.thingiverse.com/thing:3324358 cdn.thingiverse.com/renders/ce/12/67/cb/37/9582e44cf30b6e6b1efb163b604564ed_preview_featured.jpg
So simple, even I could understand this lesson...Great info... Now, so how to get the best increases in all directions???? Hummmmm????
Thomas Nolder Only way to get an increase in all directions is moar power.
Tbs xfire
Wow that blew my mind.
I think that would be a great thing on thingiverse with som kind of copper rod or pipe.
Thanks for the awesome Idea.
pixelcomet's design is already up there for this.
Nice to be able to get your hands on a Network Analyzer ($$$$). Thanks for sharing.
Jack Bisson - I actually own 2 of them ;)
good old reflector element! Nice idea, I bet it works for super 8 and others too, even dipoles. A bit less with patches
It works with any omni antenna. The issue is that the placement might change for certain antenna types. I never messed with a super8
so next question - the diamond antenna is also available for the EU version of crossfire which works with 868Mhz, could you calculate for that also the distance and cable-lengt for this mod ?
Awesome, thank you!
That's magic, and you are a magician of wireless signals.
When can we expect an analog HD FPV signal?
2016. We've had HD for a few years now ;)
Nice hack. Thanks for sharing. What I am wondering is if my Taranis X9D radio, if the Chrome plated bar at the back of the radio, as well as the add on swiveling metal kickstand that I've added are somehow also affecting the shape of the Diamond's emissions. I suspect so, because your addition of a simple length of wire has an impact on the antenna, perhaps also the "hardware" which is on the controller might also be causing some issues. Since you have the test equipment, would love to see you test a typical kitted up controller as well, to see how these metal components impact the signal.
RF pattern must look like A louisville Slugger now!
Hi. This is very informative video. please tell me which is front side and which is back side of the TBS diamond antenna? how to mount in our taranis the front facing our quad or to our self? pls suggest for the best and optimum reception. thanks
The backside is the side with the wire. The front side should face your aircraft.
Hi. Thanks! So I had mine... the tbs head logo facing st me and the vas logo facing at my quad...
THANKS A LOT!!! awesome vid
What would happen if you cut a wire and connected the two ends to make roughy an oval shape and attach it behind the antenna? So a similar shape as the diamond. Would that help get the signal behind you as well or would cancel out?
That would significantly reduce performance.
Thank you for your response and Great video
Interesting video. What frequency are these diamond antennas or indeed the Immortal T antennas tuned to? I ask as if it's 915Mhz then are they less than ideal for use in Russia or the EU where we use 868Mhz? Thanks. Great channel btw. 😄
The bandwidth of the Immortal T is much narrower than the diamond and thus, without testing it, I cannot make a recommendation to do it. The Diamond antennas work well with both 868 and 915MHz frequencies. However, to answer your question, the distance for the Immortal T and the diamond would be the same and have similar gains. However, the Immortal T might have significantly higher VSWR which could damage your transmitter.
@@CAGreve1231 Excellent response thanks. I was going to use the diamond as my primary controller TX. I just ordered the Crossfire nano diversity and two Immortal T v2 antennas for my quad so I can have one each side in the vertical position. But I watched a video just now that says that the best way is to not use the Immortal T's and take the soft dipoles you get with the nano diversity module and trim off 7.5mm. Apparently this will tune them for 868Mhz
Also the video said if I use plastic tubing and or heatshrink this will also affect the tune meaning I may need to cut a further 0.5mm off. Does this sound advisable?
@@changeagent228 - Can I recommend not trimming the antennas that come with the receiver. trimming the ends off moves them to a HIGHER frequency, not a lower one. Using a coating will certainly increase the effective length (and thus reduces the center frequency). However, I would think the effect should be rather small.
@@CAGreve1231 You are absolutely right that makes sense. I will just test them stock. On the Immortal T v2 stiff plastic version which is the top and bottom of the dipole because there are no markings to indicate top or bottom? I can see the TBS logo on one side at the middle so I can get them matched on each side of my camera mount but just not sure which side is the ground plane which I'm guessing should be pointing down given the diamond antenna on my TX will be oriantated correctly vertically like the lobe diagram on the antenna shows.
Would this also work with the antenna of the Tango 2? It would save the hassle of building in a SMA connector into the tango 2.
simple - You Are The Best
so does that mean when the diamond is mounted horizontally on a full crossfire, using a taranis radio, the taranis radio handle gives some reflection too ! ? even if the wrong dimensions
Unlikely that is does anything. The wire length needs to be very specific.
I need to make a simple mount for the radiator element to install at the field that's not tape lol. This makes the Diamond better then the TrueMox!!!!
I'm going to design a 3D printed part for that (hooking up to the lower bar of the diamond, so you can bend the RG405 as you wish, but the parasitic would stay parallel to the diamond)
@@pixelcomet - Thank you for this! Would you mind posting a link here so I can reference it in the video description?
@@CAGreve1231 no problem, will do. I'm thinking about a forum for fpv mods only. any ideas where to set up? ( I have more custom things to put there for everyone)
@@CAGreve1231 we must shorten the distance for QX7S users, the chrome handle is colliding with the parasitic element (if the diamond is vertical). For QX7S the distance would reduce to 38,5mm. could you check that problem on the X9D please?
@@pixelcomet - Why not attach the parasitic behind the chrome handle? It shouldn't interfere too much.
Can you do this with the immortal t?
this is amazing! well done. very interesting. is the non moded diamond less effective than the stock immortal T shape for radiating aside and behind me? cheers
The diamond is more effective than the "T" antenna. This is just an added boost for the Diamond.
@@CAGreve1231 hey thanks Alex. I spent hours as a kid putting tin foil on the underside of an umbrella and connecting it to a radio to hear aliens, satelites or radio broadcasts from far away, like Russia or something 😅 i had no idea what i was doing and it didn't work. wishing i had you as a friend back then! LOL Keep em flyin
Awesome hack.
As there is only one diamond for both regions, do I use the same dimensions for 868 MHz, or is it better to lengthen the reflector accordingly (16,1 cm)?
For 868, the length should be 160.5mm long and it should be 44.5mm back from the antenna.
@@vasprofessional1094 that's long ;) thanks!
@@vasprofessional1094 Hello if i have 433mhz antenna, what efector i need? Thank you for your answer.
@@chansmitbahim - Check out this video for 433MHz: ruclips.net/video/PvJ6-DjfcG0/видео.html
@@vasprofessional1094 44.5mm measured at the back edge of the antenna?
Can i using 12 awg like a lipo wire??
Can't you make the wire shorter to increase the back signal. I'm sure there is a happy medium. Just wondering.
the metal radio handle should do a similar effect unintentionally?
Most likely not. The length is very specific. If it isn't exactly correct, then the handle will have minimal effect (which is whatmost people observe).
What happens if the shape of the wire was changed. Like if you were to use a flat or square shaped wire rather than round wire?
Effectively nothing changes with the shape of the wire.
@@CAGreve1231 Thank you Alex. Interesting idea to increase confidence in frontal distance. Much appreciate the response. See You In The Sky
Hi @Video Aerial Systems. Is the TBS Diamond 915MHz antenna a directional antenna or omnidirectional antenna? Thank you!
It is an omni antenna.
@@CAGreve1231 Thank you!
We need a 3D printed piece the houses the element and places it perfectly in position 😉
A few have offered to do this and post it up for others to use. I stink with 3D software.
Lol me to plus I enjoy buying your products they've never failed me and are well worth the price in my opinion!
any idea where to get the dimensions/location of the parasitic reflector for a VAS 433 Mhz Microwave Diamond Antenna?
with such content, and darn you still under 100k ;/
Thanks for sharing. Would this work with a dipole / imortal T?
Sort of. The spacing would be different and it would de-tune the Immortal T. The Diamond is much more resilient to these effects than the "T".
awesome! a compromise would be a shortened parasitic, gaining some to the front, but keeping a little bit to the rear. am I correct?
Yes. 5.75" long gives you a fair amount more rear coverage but still goes 40% farther than the standard diamond.
Does rotating the antenna on its "roll" axis affect signal strength??
It will have a very small effect, but nothing noticeable. As long as you aren't in the dead zones of the antennas you're good.
Is this how the shapeshifter works?? I just put one on my crossfire module.. Does turning on the switch, turn on that affect?? Thank you
Why doesnt the antenna come manufactured this way I wonder?
Three reasons:
1. Size - This makes the antenna larger
2. Directionality - Most people prefer an omni-directional antenna to a directional one
3. Simplicity - A single element is much simpler than multiple parts
Your the best 👍👍👍
Will this work on the R9m Super 8 long range antenna as well???
amazing. can this be done to 5.8ghz video antenna?
How do I do this for my immortal T ?
So you added a reflector to make it a driven dipole.
you are so cool- Thanks!
is that a just wire like ve use on esc or xt60 ?
Say you use the True mox 915mhz would you even use this antenna anymore? TBS Diamond is great for being used as an antenna on the quad side receiver try it :) LONG RANGE
Alex, great tip,
any info how ground (earth) affects the antenna performance? Does it act similar to Moxon (gains drops with proximity of ground/earth)?
Will this cause some issues flying far and low to the ground, or will it retain consistent coverage at different altitudes like with the unmodified diamond antenna?
You should see an improvement in signal at all altitudes below 55 degrees with this mod. If you azimuth exceeds 55 degrees from your location, you would be better off without the mod.
THANKS YOU... Great video..
Every time you adjusted that straight wire or rod or whatever, I noticed that you stepped back. How far back are you stepping when you do that? And would this make any difference in real world circumstances? Due to you're holding the transmitter close to your body anyways. Because due to these observations (of mine just now), it seems to me as if I should either fabricate some kind of mount with coaxial extension on my transmitter 'carry bar' (or whatever the hell that thing is), or construct a stand alone mount w/coaxial extension, for my transmitter antenna. In order to not be seriously degrading my transmitter's signal with just normal usage proximity.
I am glad someone caught that! The truth is the amount I step back is simply an empirical value. In other words, I back up until the effect of my body on the measurement is negligible. There really is no set distance.
The truth is that no matter what you do, there is still a matter of uncertainty which you cannot account for.
Alex Greve Any object that comes close to the antenna is going to detune it. So if you put a reflector on the antenna as you did and then stand away from it you’re going to get a certain result. But then, when you take the antenna off and put it on the radio with someone holding the radio the measurements are going to be different. So, to make this practical for FPV use you should make a part 2 and show the results of the antenna on the radio while it is being held. Then re-tune the antenna for max results while being held 👍
@@53roger - As a general rule: anything behind the reflector is minimal. The reason for this is because the energy is being re-directed rather than making it back to the pilot or the radio. Thus, there would be little, if any change to any of the dimensions.
I bought VAS Diamond 2.4Ghz antenna. It looks like it's smaller than the TBS Diamond antenna I saw. Does size matter?
It's not the size that matters, it's how you use it!
Sorry, couldn't resist. Same antenna, just different frequency. 2.4GHz has a shorter wavelength so it is smaller.
Ah cool! Thank you so much for clarifying! Have an awesome day ahead of you! :)
@@CAGreve1231 HI, my TBS Crossfire Micro TX is arriving soon. I'm a little confused with description on the TBS Diamond antenna - www.team-blacksheep.com/products/prod:diamond_antenna It says "A slightly-directional antenna for best signal penetration". Does it mean it's still omni-directional?
i learned something today👍
Great 👍
Would this extra element fix the forward null spot on the 433Mhz diamond antennas? Can you do a quick how to video for us 70cm guys? Or at least some reflector wire lengths to start?
I can make a video today on the 433MHz Diamond if you like. There isn't a forward null spot on it, but you can definitely increase the gain.
Alex Greve you and I had this discussion about the null spot on the 433 diamond a few weeks ago. Remember I told you when I held the diamond antenna to the side my RSSI increased and when pointed forward it decreased a lot. I was in extreme conditions and distance for the environment. You said it was because of the part in the middle of the antenna. The bent part is a micro strip. It was to balance the antenna.
@@Hyprmtr - A null is "0" or no signal. When mounted near the ground, the Diamond lends more of its transmitting energy to the sides rather than straight forward which is the phenomenon you are seeing. This is caused by the geometry and the balun in the center. The difference in strength is about 1.5db or so.
Alex Greve would this modification help push the center lobe to be more uniform compared to the side lobes? I already got mine modded. I just need some good weather to try it.
@@Hyprmtr - Absolutely. I found for 433MHz, the ideal location is 3" back and the wire length should be 13".
I know you probably have stuff going on, but it would be greatly appreciated if you did a review of Crossfire antennas and how placement affects performance. Just got the large module with the immortal T and I get RSSI and LQ warnings at 500m with two vertically mounted antennas... Extremely frustrating to say the least.
Your problem isn't the RX antenna. The Immortal T signal is deflected by the ground causing destructive interference. This is the precise problem the diamond was designed to fix.
@@CAGreve1231 So even with the dead-spot facing downward you still experience this?
@@nige5572 - Watch this video: ruclips.net/video/bnK3HGzdmTc/видео.html Same principal applies to 900MHz.
@@CAGreve1231 So I did a good amount of testing. It's important to note that my antenna is mounted vertically with the same tilt as my FPV camera, and one full half of the the Immortal T is above the GoPro and the entire antenna is isolated by 3/4 from any material. Now here come's the weird part: Even with flipping the antenna to find the "active element" I still experienced this: As low as 65 LQ on 2 Watts heading out, and 99 LQ at 25mw headed back. (this is on dynamic power recorded live). This was the same with either position. The only other thing I can think of is my 5.8 antenna. It's a Lumeniier LR Axii that sticks out to the same height as the Immortal T above the quad. It is mounted 3 inches away (diagonally) from the T and is transmitting 5.8Ghz at 800mw. Do know what could be the source of this LQ/RSSI problem?
@@nige5572 - That's an unusual problem, but you have a good installation. The Crossfire should never hit 2 Watts running a quad. I can certainly help you troubleshoot the problem, but ti is best done through Email. Send me some photos of your vehicle and have someone take a picture of you flying and I will see what I can do.
thank you for that nice hack.. does this work also with the immortal Tx ? or with 2.4 linear antennas?
It works with the T-antennas well. However, the T tends to get de-tuned a bit compared to the diamond and thus the range increase is closer to 50%.
For 2.4GHz, I find a 16AWG wire 2-3/8" long mounted 5/8" behind the antenna performs best.
@@CAGreve1231 amazing. thank you alex.
i will try how far i can throw my 100mw-wifi with this trick :D
@@smokinjoe1256 - You should get another 75% range out of it ;)
Which the antenna placement for flying beneath me? Vertical or horizontal?
Always vertical. However, if flying behind yourself, do not perform this hack. It only works for flying out in front.
@@highervoltage5430 thank you
Hey Alex. In what scenarios is the diamond better used in vertical or horizontal alignment. Considering that RX antennas are diversity at 45°
This is not an easy question to answer. In general, horizonatally polarized waves travel better at low altitudes. However, the ground will change the polarization to have vertical components to the wave as well. Thus, horizontal is technically better so long as you don't fly into a null.
Thats very cool, do you think this also works for the super 8 from frsky?
Unfortunately, no. The Super 8 is an uncompleted open loop antenna and thus this technique won't work properly.
Amazing, thank mate.
Dude!!! Yes!
Is a Frsky Super 8 antenna the same as a TBS Diamond?
Not really. Will this hack still work with it? Maybe, but the location is going to be different.
Is it possible to calculate without a network analyzer?
@@philaell - Not accurately. I would guess the distance would be 1.75" or so.
@@philaell sure. Use the rssi feature. Set the quad some distance away, set the r9m to range test mode, vary the distance and work out what gives the best rssi.
@@nohandle1 I actually tried that with my diy dipole on my r9m. Rssi seemed to change a few digits but I couldn't verify if it was me moving the tx or the wire reflector moving. I'll have to test with the tx somewhere stable.
What is the gauge of the wire used?
12AWG wire. Anything from 6 to 18 AWG will do, though.
Will this work with the little diamond guy for the frsky xlite?
I'm unsure what sort of wire to use for this. Can anybody post a link to a recommended product?
Any conductive wire, I believe. Copper would be fine. You want single-strand. I'm imagining something like what is used in house A/C lines.
Is there anyway we could setup diversity for tx antennas like we do for our video systems?
Unfortunately this is a tall order simply because the transmitter is sending the signal and not receiving it. If the transmitter is allowed to receive, then we could certainly do this. Typically this is done by beam forming.
TBS just announced the CRSF Nano Diversity Receiver.
So, yes, on the receiver sie it is doable and done.
I was told the diamond antenna doesn't have any dead spots(at least thats what the person stated), so does that mean if I do this mod I won't be able to fly behind myself(I do that now with no issues) and have to worry about dead spots?
The diamond has very small dead spots that don't really have a large affect on RSSI or LQ. If you do this mod you will basically have no effective range behind you as you are utilizing a parasitic reflector to reflect the signal output in one direction. Look at his FPV antennas video if you want a visualization. The diamond (equivalent of an omni) was just turned into a directional antenna.
Interesting, thanks for the share
are the measurements available for 868mhz with the diamond
SImply scale it by multiplying your measurements by 915/868: Element length:160mm Distance behind the diamond: 43mm
Would this work on the super 8 antenna for the frsky r9m ?
One more question pls. Would this same 'hack' work on the FrSky Super 8 (R9M 900mghtz•?•) antenna. (Asking because I have it on order already.)
Sort of... The distance will be a bit different (1.75" if I had to guess). The super 8 has no documentation so it it really just a guess.
@@vasprofessional1094 that machine that you work/test with, probably out of the average person's budget range huh?
@@DavidHanniganJr - It is. You can pick one up used for about $10,000 or so which puts it well outside of DIYer territory. However, you can use 2X RFExplorers and create a makeshift version of this machine for about $500.
@@vasprofessional1094 LOL! As i suspected
When are you making a batch of Diamond yagi crossfire antennas lol awsum dude
I am researching a new technology for control right now. This is just a quick modification which I have no intention of marketing or selling.
What kind of 12 gauge wire? Solid? Stranded? Copper?
Literally any metallic wire will work for this. Even a steel TIG welding wire will work. Just use whatever is convenient for you and it will work well.
@@highervoltage5430 does it have to be 12 gauge. I printed the first stl he has listed. The only thing that fits is a very small wire.
Does this work with the stock dipole tx? Thanks
Not really. You increase gain a little bit, but SWR goes up considerably.
@@CAGreve1231 Thanks for the reply and awesome products
@Alex is it impossible to only do half? Get best of both worlds by covering only half of the back of the diamond?
What do you mean? Only reduce the rear range to half?
@@CAGreve1231 no if you only applied the wire from the center out on one side. I hope this isnt crazy, just a thought?
@@CAGreve1231 obviously this is amazing I just didn't know if that could possibly both increase directional signal and also possibly retain higher DBI omnidirectional too? Thanks again
@@cenabitednbfpv587 - You mean 1/2 length of wire (3")? It would not work at all. The wire will be too short.
@@vasprofessional1094 ty, that's why your the man, the thee turn helical has been my go too since the day I got it. All time fav for my range atm. Ty, again n always looking for a new VAS ANTENNAS worth every penny!! 😎
So is the stock antenna better for general usage?
If you aren't doing long range, keep the stock the way it is.
Does this work only on the diamond antenna or could I try this on the regular dipole? What wire length for 868 Mhz?
Same question here
It works on the dipole as well. Same distance and everything. It just de-tunes the dipole a bit.
👍 👍 👍
got a sub from me, great stuff!
So you recommend placing the antenna vertically on the tx ?
serval FPV It doesn’t matter how you mount the antenna. What natters is when flying, the antenna on the tx is point toward the quad like he is showing in the vid
@@53roger obviously the antenna has to point to the quad im hardly going to hide it... but i want to get the optimum range so should it be tx & rx horizontal / vertical 1 each way theres surely a correct and wrong way to set it up !
serval FPV to get the maximum signal the tx and the rx antennae need to be situated in the same ‘plane’. So generally speaking, the antenna on the quad and how it’s mounted determines whether it is horizontal or vertically polarized. For example, if you used a TBS immortal T antenna mounted vertically on your quad then you would want your radio transmitter antenna mounted vertically and vice versa hope this helps
Will this work with the 2.4 diamond antenna as well?
Yes. Length of wire: 2-3/8" 5/8" behind the element. This is actually a 5db increase which means it almost doubles your range.
How does this work?😅
NoPro_Fpv - Same way a Yagi antenna does. Same tech. It is actually just a 2 element Yagi.
Which wire you use for that?
Nice 💪
will this work on 1.2ghz dipole?
No... but you can do a similar mod. I have a tutorial on it here: www.rcgroups.com/forums/showthread.php?1266148-Build-your-own-Homebrew-Yagi!!!
Alex Greve nice, thanks alex
i just checked it, the dipole became a yagi right? question is, does the additional elements have wire connections on the main antenna? i don't see any from the pictures
@@don0219 - This is as simple as it looks. Yes, I made a simple 2 element yagi. No electrical connections. It is just a 6" section of wire 1-5/8" behind the antenna. There are a few 3D printable parts on thingiverse so you don't have to ghetto-rig it with electrical tape like I did.
Great video. I will buy the diamond antenna. Crossfire fail-safes like crazy at less than 100m distance and I have done everything TBS has told me to do. Do you think the diamond antenna will solve this problem or is it a firmware issue? I use v2.41 on a big crossfire 500mW static power.
Antenna is not your problem unless it has some factory defect, look somewhere else. Unsoldered/disconnected pigtails inside the module has been reported
@@slavikarg Thanks, yes loose pigtails has been a problem for many. Tbs told me to check that on the the first crossfire micro transmitter. Then they sent me a new micro transmitter and they told me to check the pigtail again. Then I asked them to send a big crossfire, same problem. And I have two nano receivers, same problems. Firmware 2.24 was terrible and I updated to 2.41 which I think is better but I still get failsafe and I lose control here and there for half a second and it feels really wrong.
Failsafes at 100m tells me something is very wrong and you need to find what is causing the issue. This mod would only be a band-aid fix. I would suggest investigating the issue further before trying mods like this to fix it.
@@vasprofessional1094 Thanks Alex, but after Tbs keept sending me new transmitter modules and I sent them photos of my installations of two different quads, I'm running low on ideas what to do. I have done everything they suggested and sometimes it can work for a while and then there is a failsafe or a second of lost control.
So for me, even if I'm an engineer and I have a reasonable good experience trubleshooting booth hardware and software, if someone tell me to stand on one leg when I fly, I will try it...
@@Siamect - This sounds like a receiver issue to me. Usually range loss is in the receiver. The u.fl connector isn't very good for FPV use despite what people want. That would be the place I look.
ahhh yeah!!!!!
Black magic sorcery
It still feels like that to me, too.
Hacking it like that will give you range but also some pesky random lobes. Have fun pointing it bvlos :p
Make things right, rigid, good materials like extruded aluminium pipe, a solid boom, tight reflector mount.
Tape won't do it very well for very long.
Aluminum pipes and such will cause side-lobes. Tape won't. The idea behind this was to inspire some people to design some 3D printed mounts. Within 5 hours of posting the video, pixel comet designed a 3D printable TPU mount.