I have to shake my head at anyone into FPV that does not subscribe to this channel. Josh may be called “knowitall”, but it’s because he “knows it all”. Thank you for the effort, I’ve used your videos as a first resource for trouble shooting my issues and you’ve saved me countless hours and dollars. Thank you again.
Holy crap, this is absolutely true. I was getting about 1/4 mile away when my Taranis warned me of low signal strength. After straightening out the ends and heat shrinking them, I can go farther than I can see the quad. Thanks for the tip! Old news for a noob!
For those that want to know. The receiver antenna wire is RG178. Cheaper in bulk than to buy premade as antennas. Just make sure you follow Joshua's trimming instructions. that is the most important part.
Thanks very much for this! I actually only have about an inch of shrink tube on the tip of the zip tie. I'm only into the hobby less than 1 month though, and have been learning a lot, thanks to your channel.
I guess im asking the wrong place but does anybody know of a way to get back into an Instagram account? I was dumb lost the password. I would love any assistance you can offer me
@Merrick Finley i really appreciate your reply. I found the site thru google and Im waiting for the hacking stuff atm. Seems to take quite some time so I will reply here later with my results.
@Merrick Finley DAMN IT REALLY WORKED! Just hacked my IG account after about 45 mins by using the site. Just had to pay 15 $ but for sure worth the price =) Thank you so much, you saved my account!
It was helpful, and you are 100% right. Ive recently got Eachine Aurora 100 and first flight YOLO - my antenna got chewed UP. Immediately the RSSI went to 30% on 10m and Aurora started switching to FS. Went home, straightened antenna, added zipties, shrink tube and made the tip/radiator longer as on my previous FrSky receivers. Now I can fly with ridiculous 300m built in receiver as far as I am comfortable to go.
"This is the most important part! This is your antenna!" LMFAO! I shall go and fix up my shoddy antennas on an immediate basis. What's helpful dealing with stripping the coaxial cable, and soldering the antenna back onto the RX in case it's come off as it has in my case, is to get a buddy to do it for you :D
Hit the nail on the head. I see so many bunny eared quads with ragged tips and tell them all the same thing. You shrink wrapped and protected the least important part your antenna and left the heart of the antenna to beaten to death. And then they blame the carbon fiber for the failsafes. Great video!!!
Oh man, I feel so dumb now. I've lost so much time trying to understand why my receiver doesn't work properly while only the final bit of my antenna was cut. Thanks Joshua!!! :)
I like the voice change at 4.40, LOL . Ive had a few of the " Why are people so stupid " moments this week, when I heard "This is the most important part...." I cracked up. Thanks for making my week.
Can we use thicker antennas? I ordered 20 because they are pretty weak. Nice video. I once made an antenna for my WiFi router out of a piece of jumper wire. It happened to work and I'm still not sure why. Lol
Both antennas on my quad got sucked into props and cut after many flights. It still works for the most part though the entire 2 inches are cut off of each antenna (Futaba receiver). After watching this video, I can rejuvenate the cut antenna's by cutting the shielding on the outside to the same length that they were originally and they will be good as new, actually better than new because they will not be so long as to get sucked back into the props on the next crash! Now I need to go find the length needed for 2.4ghz antenna (roughly 29mm).
I've just crashed and have some exposed metal in the shielded part of the antennae...nearer the reciever (frsky) than the end. Not severed but some insulation was rubbed off against the carbon frame. I'm assuming I can just patch the exposed part and go...but thought I'd check before sending into the blue : ) Thanks for all the knowledge shared and well balanced infotainment!
I think people are leaving their antennas exposed because they don't know that most heatshrink is rf transparent. At least I didn't before having to repair one of my antennas
Be sure to know what you have first, I unknowingly put "shielded" heat-shrink on and it bound and flew until I was upside down about 100 feet up and completely lost signal. I tested by putting in a microwave...and the shielded tube reacted with the microwaves and heated up, while the regular tube didn't warm up at all.
putting a small section of heat-shrink tube in your microwave for short durations (10 seconds) is pretty safe I believe. They will either have NO reaction and be the same temperature after...or very slightly be warm to the touch after a few seconds. I only think you would run into any sort of issue is if you stuck a whole roll of shielded tube and set the microwave for 30 minutes or something crazy.
I don’t let the antenna go completely up the arial of my RC cars anymore as the tops were getting damaged. It’s not a problem when building my own kit but a lot of RTR vehicles come from the factory with their antennas sticking out the top. I like to leave a few inches of tubing above the end of the antenna for protection and if possible I try to keep the whole antenna underneath the body since theirs usually never a problem with range on land vehicles when using decent equipment.
Awesome advice. I am guilty of this and been wondering how folks keep the important part from being damaged because seems everyone keeps that portion exposed. So why do the manufactures not simply protect that portion with shrink wrap and save us the trouble of trying to find something that is RF safe.
The industry is not very helpful with this, and that is most likely why there is a prevalence of misapplied antenna mounting. I wouldn't necessarily blame this on the user, when the instructions provide no guidelines. Why are there no standardized supports for these antennas? Why do I need to use straws? When I purchased the ImmersionRC Vortex 250 Pro, everything fit perfectly except there was no place for mounting the receiver antenna nor any suggestions on how to mount it. There is also no suitable place to put the antenna on the top of the quad without risk of having the wire chopped to pieces by the props. Currently I have my antenna mounted on the bottom of my quad with electrical tape, with the radiating portion dangling below the quad, which prevents the props from causing a problem, but the mount is less than ideal.
Great video as always, keep 'em coming! If I put my antenna in a plastic tube like an airplane pushrods tube or even a coffee stirrer, and that tube is long enough to cover the antenna all the way to the end, will that "insulate" the antenna and reduce my range?
I have normally with my 72 Mhz antenna exited it from behind the cockpit and fixed the end to the fin with a t pin and a rubber band with the antenna looped through the rubber band. It seemed to work but should I stop doing this for the risk?
Can't understand your video is it OK to put receiver wire slightly out of plans mine has a rubber inch piece on not on end 1ins down. I was told better reception wire out side
Is there any way to repair a cut through RC antenna (VTX or Rx antennae) ? I’ve ordered others but there’s something stopping me throwing the cut off section but soldering doesn’t seem suitable (?!)
Agreed, kinks are no good. But what about smooth gradual bends? I route my antenna in a way so I have very little exposed from the frame. The rest of the antenna is tucked in routed in a way with no stress yet in gradually bends twice before exiting the frame. I'm an electrician by trade, so clean and aesthetic wiring is big to me. I just want to make sure I'm getting the most out of my rig. I've just recently subscribed to your channel, I've been watching a ton! Thanks man!
i did it wrong for months.. mainly because of my ignorance.. i thought putting heat shrink or tubing over the end would block the signal. Someone pointed it out to me a while back and informed me that it doesn't, and that that portion of the antenna should be protected.
Hello! you seem pretty sharp about this antenna stuff can i put a coax antenna on a syma x5 toy grade quad for better range ? ive already modded the antenna in my remote but want to go farther.. over 400 meters if possible ? i realize i can add a helical or a yagi to my remote, but im seeing if i can squeeze any more range out of the receiver board first, thanks in advance!
The shield also radiates. This type of antenna (monopole) needs to work with a good ground and the shield is part of that ground (and so is the rest of the quadcopter if you have a carbon fiber frame). Ideally, the ground radiates just as much as the active element. The main thing with monopole antennas is to keep them sticking up away from the ground. Placing them very near and parallel a grounded object like the frame will cause poor radiation. Also, when there are two antennas it is good to keep the active elements ("the most important part!") at right angles to each other so that you get polarization diversity. In other words, don't have the two elements parallel to each other.
+Joshua Bardwell I have not used the OrangeRX receivers but I have lots of experience with small transmitter boards that use a wire antenna direct-soldered to the RF output pad. The monopole principles are the same in this case: The wire needs a ground in order to function efficiently. For really small receivers/transmitters the main RF ground can be the battery and the wires connected to the battery. For quads with conductive frames the quad itself is the RF ground so you would want the OrangeRX antenna wire to stick out from the board and frame in order not to short the RF to ground even though the wire is not physically connected to ground.
Would it be a problem if you shorten the opposite end of the cable to solder onto a board? I ended up shortening the 2.4ghz cable from my flysky GT3C before soldering back onto the board. To be clear, the entire external antenna is untouched, just the soldered end was shortened by a good inch.
I have a question. The two wires coming from the receiver are shielded the entire length. And you state the very end is the most important. Where exactly is the signal being received along the length of the antennae? The whole length? The very very tip? 1mm from the end? 2mm? 10mm? And why can't i just hook up two similar antennas on my TX like they do on the RX? Wouldn't that broaden the range and coverage area? And I'm not talking diversity antennae... just say 1 3db and a 5db Omni. And how do i tune the length of wire inside my TX and on my RX. How do you check your TX to be sure it's putting out the exact bandwidth it's suppose to be or RX? You've shown in other videos all things aren't as they seem for FFC approved modules... maybe things aren't as they claim in this regard too. Or maybe they are... i don't know. Do you? I'm going back into my sponge mode now awaiting some teaching. cheers...
Can the cable portion (NOT the important antenna portion) be bent (let's say 90 degrees) without affecting range? You mentioned that the cable portion is just to transport the signal from A to B and it radiates nothing.
hello, I'm putting together a drone with the following components a pdb matek, a fc sp racing f3, esc hobywins. I have everything connected and configured in betaflight, but the motor 4, when I arm and I give gas to the stick to raise this one heats up and esc also. change engine and esc connect and the same thing keeps happening. I need your help that may be happening ...?
What about lenght.... maths say the antenna should be 30-31mm long.. however Frsky antennas come at 34-35mm ... are they wrong? or is there something im not taking in count?
I know i'm digging up an older post, but what I find difficult to understand is why ie. flysky is using a lot less of a length on their antennas. I've seen 23mm and 26/27mm. Searching on the web is even more confusing as you read a lot of opinions rather than facts.
I saw a video a while back that the guy said his rc club showed him a trick to get better signal, which was to bend the antenna at the end. I think though he was talking about the fpv camera`s antenna? True or false?
hey Joshua, I'm using a frsky v8fr-ii. it's brand new, and losing signal 1-3 times per flight (at 20-60m), antennas are new from factory at a 90deg and undamaged. do I need a new receiver, or could it be something else?
Very helpful. You know, I know about antenna tuning, but still dont apply any knowledge to my copters. I just put that thing in the air. I broke an antenna in half,, and was going to think about soldering the missing length onto the end,, but i did not know only the tip was actually antenna. I just thought it was some longer portion of tge wave. (Well, I knew 2.4 bagiga-hz was around 12 cm, but I just figure I shouldnt question the engineering, even the cheapest crap is usually very well engineered compared to any work I might try).
i have a the turnigy evolution ia6c receiver the antenna is soldered in if i buy the antennas with the end on them that plug in can i just cut that off and solder it in thats all i can find for sale
+bing crosby To elaborate, coax length matters a little bit, because the coax causes some loss in signal strength. The longer the coax, the more signal is lost. But the coax length doesn't affect the tuning of the antenna like the length of the un-shielded section does. And the difference between 3" and 2" is completely trivial when you consider that the overall range of the control link is over a km. In theory, if you were trying to break range records using 2.4 GHz, you might benefit by shortening up the antenna coax length as much as possible, but for most of us, it's irrelevant.
+Vic Prk (Slick Vic) they are the same as shown in this video, but over the ground mesh coming from the cable there goes a metal tube back over the antenna. Its also used on the linear polarised FPV antennas you get in your fpv transmitter sets, it just helps to get a better signal by making the lanth more precise. easiest thing would be, just cut open 1 unused FPV linear pol. antenna, you´ll understand once you see it ;)
Good video, but I think you missed the "why" people do it wrong. I think a lot of folks probably are under the misconception that covering the antenna portion with something non conductive like a plastic straw will kill the signal.
+Robert Baltrusch You know, I never thought of that. I have worked with RF so long that it didn't even occur to me people wouldn't know that plastic doesn't effect RF transmission.
+Joshua Bardwell Funny because when I started in this hobby, I was trying to emulate what everyone else was doing. Every 2.4 antenna I seen had the top unprotected and curled over. It seemed so delicate that I decided to cover it even if it was "wrong", thinking I was just sacrificing range for durability. But now I know! :)
+Joshua Bardwell One question I've had in the back of my mind. I don't have a fancy schmancy Taranis, I have an at9. When I learned about how to repair the antenna awhile back, I measured another RX antenna and it was 2-4mm shy of a qtr wavelength. I made it the correct size, but now I'm wondering...do some manufactures tune their radios to a little less or more than 2.4? Or is it a safe bet that every radio is supposed to be exactly 2.4? Actually, I just had a thought. Is the Antenna inside the controller the exact same? Wonder if I could open it up and make sure they match perfectly?
+Joshua Bardwell maybe you could do a video on RF transmission, and how things like carbon fiber, metal, shield/reflect the signal. Multipathing etc. Maybe show people how they can shield a part of their antenna on their frsky or other rssi enabled radio to make it directional and find a lost model using the rssi ( a trick I've showed a lot of folks at my club, and they were more than impressed.)
Chris E I would go with whatever the manufacturer decided. The tuning will typically be for the middle of the band. So the 2.4 GHz band actually goes from 2.4 to 2.5 GHZ. So the tuning of an antenna would actually be for around 2.45 GHz, which would slightly lengthen the antenna. There may be other aspects of the antenna system that affect the tuning, so the antenna element may end up being optimally tuned when it is not quite exactly a quarter, half, or full wavelength. If you have an antenna analyzer ($$$) or an RF power meter ($$) then you can test the effects of different antenna designs, but if you don't, then your best bet is to copy the factory antenna as closely as possible, on the assumption that the manufacturer probably knows what they're doing.
I think there are probably better ways to go about it than solder. Hot glue is fine. You can just turn them 180 degrees so they lay back across the receiver, then use some electrical tape to hold them down.
I feel like such a dummy and should google some good antenna theory, but has any conclusion been reached on FrSky's apparently "wrong" length of their XSB antenna (Being different from 1/4 wavelength)? I keep seeing possible explanations, but nobody draws a conclusion. I would think I'm just missing it. I saw their coax as being an integral multiple of the wavelength (Which I thought was irrelevant in an impedance matched setup), and their antenna length was too short or long for the 1/4 wavelength typical "target". ALSO: How does the characteristic impedance of the transmission line and that of the antenna compare? The coax is going to be relatively constant over a large frequency range, while the antenna is designed for a specific narrow band of frequencies. Right? Does the antenna have a purely resistive characteristic impedance at this frequency point, that's equal to the transmission line's? That would seem to be the obvious answer. I would think the resistance of the antenna dummy loads would be that. Did I see the one you were using on the X10 as 50 ohm? I know there are antenna tuning gadgets at the source that minimize VSWR, but can this actually change the output performance of an incorrect antenna length to that of an antenna of optimal length, or is it only protecting the transmitter from reflected energy? For an RF guy these questions are probably retarded.
+ibfisher the video signal is much more intensive than the control signal. That's why the range is so short. There are various things you can do to improve range, but too deep a topic to discuss on mobile right now.
+Joshua Bardwell are there actually any benefits of going for the lower ends of the 5.8ghz spectrum to increase range? the 5.8g frequency is very high and the lower the frequency, the longer the wavelength and therefor the better the air "penetration" so to speak, right? so wouldnt that in turn mean that going 5665mhz instead of 5945would yield slightly better signal strenght, at the cost of slightly higher latency? ah, the difference would probably be imperceptible, right?
+3R45U5 Not really. The main effect of channel choice would be 1) whether there was more or less interference on that channel, including background noise, and 2) most importantly, most transmitters put out more power on some channels than on others--often a significant amount.
Josh does the diameter matter? I bought some coaxial to make fpv transmitter antenna, can I use this wire on a radio receiver? I have an orange Rx with diversity and one of them was lopped off at the plastic... so I need to shield the soldier joint somehow?
Scratch that JOSH. I opened the case and it uses those quick disconnect pieces that are like $1 each. Not worth soldiering! Thank you for your channel, I do "lean something today". Regularly!
When you were talking about it being bent, it made me think of circular polarized antennas. Does that have any relation to it or am I just trying to hard to have big smart brain head thing.
+Razor E I have pulled more antennas than you know off of X8R and D8R and D4R receivers that are either dead or that I just won't use any more. You can get replacement antennas for about $2 or less, so it's handy to have some spares around. But in a pinch, in the field, if you absolutely have to, you can get the job done with a razor knife or a delicate hand on a pair snips.
The X8r antennas are printed circuit boards, not wires. Diversity is maximized if they are 90 degrees to each other, but it's not required. For more, see one of my earliest videos. ruclips.net/video/JlaBpd0Rs-k/видео.html
It's true, even I do it and I already know better! Lol I can tell that really grinds on you doesn't it? What about racers that tape them to the arms though? The carbon fibre (particularly if it's grounded to the fc) acts as sheilding! But isn't the foremost thing to do is get them up and as far away from rapidly changing magnetic fields as possible?
Man I'm sure you're tired of me by now but I have a question. You said if you change the length of the wire it affects tuning frequency. but at the end of the video you say it's okay to cut the end off and strip the shielding back and your good to go. I thought you have to splice on another piece to make it the same length it was?
+Tyler McDonald The overall length of the antenna doesn't matter. What matters is the length of the exposed center lead at the end. So you can cut it off and strip back the outer sheath and shield to re-expose the correct amount of center conductor.
+Tyler McDonald Thanks Bruce for fielding this one. Yes, the key part is the length of the un-shielded section. That is the section that is acting as the antenna. The whole point of the grounded shielding is to prevent the whole wire from being an antenna, and therefore, affecting the tuning.
Not only that bent antenna is not tuned, but also changes radiation pattern. Such whiskers antennas are pretty bad, it can be improved a lot. But I will not post any link to my videos. It is really bad taste to spamming others.
+fpvYou Because they are circular polarized on both the transmitter and receiver. The radio transmitter antenna is linearly polarized, that's why the receiver benefits from a straight antenna as well.
+fpvYou without going into too many details, it depends in the design of the antenna. The type of antenna used in "whiskers" is a dipole, and it needs to be straight.
+fpvYou I'm not knowledgeable enough about antenna design to tell you for sure, but I believe what you are seeing there in the "wavy" section is an impedance matching transformer. But the bottom line is this: some antennas are designed to be wavy and some antennas are designed to be curved and some are designed to be straight. But the reception and tuning of the antenna depends very critically on the antenna being as it was designed to be. Your "whisker" antenna is designed to be straight, not kinked. If it's kinked, your range is being affected. Now you may honestly never notice this, because the range of a FrSky system (for example) is so much farther than many of us ever fly. So even if you are cutting your range in half or one quarter, you may still have fine signal strength. But from the perspective of best practice, the antennas should be straight.
I have to shake my head at anyone into FPV that does not subscribe to this channel. Josh may be called “knowitall”, but it’s because he “knows it all”.
Thank you for the effort, I’ve used your videos as a first resource for trouble shooting my issues and you’ve saved me countless hours and dollars. Thank you again.
Holy crap, this is absolutely true. I was getting about 1/4 mile away when my Taranis warned me of low signal strength. After straightening out the ends and heat shrinking them, I can go farther than I can see the quad. Thanks for the tip! Old news for a noob!
For those that want to know. The receiver antenna wire is RG178. Cheaper in bulk than to buy premade as antennas. Just make sure you follow Joshua's trimming instructions. that is the most important part.
Might be useful for those who have an XSR where the antennas are solder-on. Not so much for those who have an X4R with U.FL connectors.
Joshua Bardwell I run the xsr. ;)
Bruce at RCMODELREVIEWS is the man, he is like a professor in RC lol
New to R/C and building my own aircraft, this explanation of Rx antenna theory was very helpful indeed. Thank you.
Thanks very much for this! I actually only have about an inch of shrink tube on the tip of the zip tie. I'm only into the hobby less than 1 month though, and have been learning a lot, thanks to your channel.
You explain things in such a way that makes it so easy to understand. You deserve more subs!.
I guess im asking the wrong place but does anybody know of a way to get back into an Instagram account?
I was dumb lost the password. I would love any assistance you can offer me
@Malik Leighton instablaster =)
@Merrick Finley i really appreciate your reply. I found the site thru google and Im waiting for the hacking stuff atm.
Seems to take quite some time so I will reply here later with my results.
@Merrick Finley DAMN IT REALLY WORKED! Just hacked my IG account after about 45 mins by using the site.
Just had to pay 15 $ but for sure worth the price =)
Thank you so much, you saved my account!
@Malik Leighton Happy to help =)
See man thank goodness you put these videos up. I'm one of those morons making that mistake. But now going to fix it cuz of you thank you Josh!!!!
It was helpful, and you are 100% right. Ive recently got Eachine Aurora 100 and first flight YOLO - my antenna got chewed UP. Immediately the RSSI went to 30% on 10m and Aurora started switching to FS. Went home, straightened antenna, added zipties, shrink tube and made the tip/radiator longer as on my previous FrSky receivers.
Now I can fly with ridiculous 300m built in receiver as far as I am comfortable to go.
"This is the most important part! This is your antenna!"
LMFAO!
I shall go and fix up my shoddy antennas on an immediate basis.
What's helpful dealing with stripping the coaxial cable, and soldering the antenna back onto the RX in case it's come off as it has in my case, is to get a buddy to do it for you :D
You are amazing, knowledgeable, and entertaining.
+skunkman62 That's so kind of you to say! Thank you!
+Joshua Bardwell You're welcome mate. I was reacting to how you can make a topic like antenna wire so engaging.
Hit the nail on the head. I see so many bunny eared quads with ragged tips and tell them all the same thing. You shrink wrapped and protected the least important part your antenna and left the heart of the antenna to beaten to death. And then they blame the carbon fiber for the failsafes. Great video!!!
Oh man, I feel so dumb now. I've lost so much time trying to understand why my receiver doesn't work properly while only the final bit of my antenna was cut. Thanks Joshua!!! :)
I like the voice change at 4.40, LOL . Ive had a few of the " Why are people so stupid " moments this week, when I heard "This is the most important part...." I cracked up. Thanks for making my week.
4:40
It's like watching after school specials or "The more you Know" commercials. Thanks!
As always you have the best most informative videos, thanks so much for taking the time to help us out.
+Wade Pruetz My pleasure!
Confirmed my suspicions. Great video!! Thanks.
Thanks for the explanation, I didn't know the function of the outer part until now
Can we use thicker antennas? I ordered 20 because they are pretty weak. Nice video. I once made an antenna for my WiFi router out of a piece of jumper wire. It happened to work and I'm still not sure why. Lol
thx, learned something new today : )
That explains why my Moskito 70 (diversity edition) drops the signal so much easier than my mini quad.. Thanks JB!
Both antennas on my quad got sucked into props and cut after many flights. It still works for the most part though the entire 2 inches are cut off of each antenna (Futaba receiver). After watching this video, I can rejuvenate the cut antenna's by cutting the shielding on the outside to the same length that they were originally and they will be good as new, actually better than new because they will not be so long as to get sucked back into the props on the next crash! Now I need to go find the length needed for 2.4ghz antenna (roughly 29mm).
I've just crashed and have some exposed metal in the shielded part of the antennae...nearer the reciever (frsky) than the end. Not severed but some insulation was rubbed off against the carbon frame.
I'm assuming I can just patch the exposed part and go...but thought I'd check before sending into the blue : )
Thanks for all the knowledge shared and well balanced infotainment!
If the braided sheath is intact, you should be okay.
Thank you so much for this video. Short, sweet, ages well.
I think people are leaving their antennas exposed because they don't know that most heatshrink is rf transparent. At least I didn't before having to repair one of my antennas
+Nathan Haman I think you're probably right.
Be sure to know what you have first, I unknowingly put "shielded" heat-shrink on and it bound and flew until I was upside down about 100 feet up and completely lost signal. I tested by putting in a microwave...and the shielded tube reacted with the microwaves and heated up, while the regular tube didn't warm up at all.
+PowerScissor is there a safer way to test that?
putting a small section of heat-shrink tube in your microwave for short durations (10 seconds) is pretty safe I believe. They will either have NO reaction and be the same temperature after...or very slightly be warm to the touch after a few seconds. I only think you would run into any sort of issue is if you stuck a whole roll of shielded tube and set the microwave for 30 minutes or something crazy.
+PowerScissor Thank you :) I appreciate the tip.
I don’t let the antenna go completely up the arial of my RC cars anymore as the tops were getting damaged. It’s not a problem when building my own kit but a lot of RTR vehicles come from the factory with their antennas sticking out the top. I like to leave a few inches of tubing above the end of the antenna for protection and if possible I try to keep the whole antenna underneath the body since theirs usually never a problem with range on land vehicles when using decent equipment.
Awesome advice. I am guilty of this and been wondering how folks keep the important part from being damaged because seems everyone keeps that portion exposed. So why do the manufactures not simply protect that portion with shrink wrap and save us the trouble of trying to find something that is RF safe.
The industry is not very helpful with this, and that is most likely why there is a prevalence of misapplied antenna mounting. I wouldn't necessarily blame this on the user, when the instructions provide no guidelines.
Why are there no standardized supports for these antennas? Why do I need to use straws? When I purchased the ImmersionRC Vortex 250 Pro, everything fit perfectly except there was no place for mounting the receiver antenna nor any suggestions on how to mount it. There is also no suitable place to put the antenna on the top of the quad without risk of having the wire chopped to pieces by the props. Currently I have my antenna mounted on the bottom of my quad with electrical tape, with the radiating portion dangling below the quad, which prevents the props from causing a problem, but the mount is less than ideal.
WAT? RC Antenna pipes have existed for decades. Antenna mounts just as long.
Nick Fessel I like what you said vs the other guy who called people stupid for not knowing this.
zipties and heatshrink.
I'm so guilty of this... I promise to have straight antennas for now on.. Thanks for the lecture.
ist great work for me.. thanks for your video. the point is 30mm unshielded wire.
Great video as always, keep 'em coming! If I put my antenna in a plastic tube like an airplane pushrods tube or even a coffee stirrer, and that tube is long enough to cover the antenna all the way to the end, will that "insulate" the antenna and reduce my range?
+rondarling4 Not at all, because the plastic tube is not electrically conductive.
I have normally with my 72 Mhz antenna exited it from behind the cockpit and fixed the end to the fin with a t pin and a rubber band with the antenna looped through the rubber band. It seemed to work but should I stop doing this for the risk?
Can't understand your video is it OK to put receiver wire slightly out of plans mine has a rubber inch piece on not on end 1ins down. I was told better reception wire out side
Is there any way to repair a cut through RC antenna (VTX or Rx antennae) ?
I’ve ordered others but there’s something stopping me throwing the cut off section but soldering doesn’t seem suitable (?!)
Agreed, kinks are no good. But what about smooth gradual bends? I route my antenna in a way so I have very little exposed from the frame. The rest of the antenna is tucked in routed in a way with no stress yet in gradually bends twice before exiting the frame. I'm an electrician by trade, so clean and aesthetic wiring is big to me. I just want to make sure I'm getting the most out of my rig. I've just recently subscribed to your channel, I've been watching a ton! Thanks man!
+Friedrick Michel smooth curves are fine. If you really want to you could look up the maximum bend radius for the type of cable used.
+Joshua Bardwell I mean minimum bend radius.
i did it wrong for months.. mainly because of my ignorance.. i thought putting heat shrink or tubing over the end would block the signal. Someone pointed it out to me a while back and informed me that it doesn't, and that that portion of the antenna should be protected.
I believe your antenna at 2.4 Ghz should be 4.91786 inches long. this is one full wavelength. It could be shortened to exactly 1/2 or 1/4.
thanks for this, Joshua. I learned something today!
Hey I have a problem my control not sending sing to my servo but they work before I stop young rc for 1 year .what cut be
Thin 2mm heat shrink tubing will help keep it straight and prevent damage.
Thanks for helping me learn.
When I uncovered the big plastic antenna cover on a Spectrum 9D, it was quite a letdown. A little wire!
THIS IS THE FUCKING AWNSER TO WHY IM NOT GETTING RANGE NO MORE THANK FUCKING YOU DUDE YOUR AWSOME
Thanks for the video, very helpful!
Thanks Joshua, really helpful.
dude omg thank you for this video i needed this so bad i fixed my antena straitened it a protectedit it works so much better
Great vid, learned something new!!!
What stop signals from antenna
If reciver antina little bit cut then what will happen bro
thanks just wat i was looking for
Hello! you seem pretty sharp about this antenna stuff
can i put a coax antenna on a syma x5 toy grade quad for better range ? ive already modded the antenna in my remote but want to go farther.. over 400 meters if possible ? i realize i can add a helical or a yagi to my remote, but im seeing if i can squeeze any more range out of the receiver board first,
thanks in advance!
does putting heat shrink that covers the whole antenna until the end of it's length, affects the range?
No
The shield also radiates. This type of antenna (monopole) needs to work with a good ground and the shield is part of that ground (and so is the rest of the quadcopter if you have a carbon fiber frame). Ideally, the ground radiates just as much as the active element. The main thing with monopole antennas is to keep them sticking up away from the ground. Placing them very near and parallel a grounded object like the frame will cause poor radiation. Also, when there are two antennas it is good to keep the active elements ("the most important part!") at right angles to each other so that you get polarization diversity. In other words, don't have the two elements parallel to each other.
+Scott Radcliffe how do the OrangeRX receivers with no coax, and just a piece of wire soldered to a pad work?
+Joshua Bardwell I have not used the OrangeRX receivers but I have lots of experience with small transmitter boards that use a wire antenna direct-soldered to the RF output pad. The monopole principles are the same in this case: The wire needs a ground in order to function efficiently. For really small receivers/transmitters the main RF ground can be the battery and the wires connected to the battery. For quads with conductive frames the quad itself is the RF ground so you would want the OrangeRX antenna wire to stick out from the board and frame in order not to short the RF to ground even though the wire is not physically connected to ground.
Would it be a problem if you shorten the opposite end of the cable to solder onto a board? I ended up shortening the 2.4ghz cable from my flysky GT3C before soldering back onto the board. To be clear, the entire external antenna is untouched, just the soldered end was shortened by a good inch.
No, that doesn't matter.
Thanks for the reply!
The game have forever changed!
I already do that. shrink tube the whole bad boy to a zip tie.
Matthew Doherty New to the scene. Great idea, doing this. 🤘
Very helpful thank you.
I have a question.
The two wires coming from the receiver are shielded the entire length. And you state the very end is the most important. Where exactly is the signal being received along the length of the antennae? The whole length? The very very tip? 1mm from the end? 2mm? 10mm?
And why can't i just hook up two similar antennas on my TX like they do on the RX? Wouldn't that broaden the range and coverage area? And I'm not talking diversity antennae... just say 1 3db and a 5db Omni.
And how do i tune the length of wire inside my TX and on my RX. How do you check your TX to be sure it's putting out the exact bandwidth it's suppose to be or RX?
You've shown in other videos all things aren't as they seem for FFC approved modules... maybe things aren't as they claim in this regard too. Or maybe they are... i don't know. Do you?
I'm going back into my sponge mode now awaiting some teaching.
cheers...
Is it okay to put heat shrink on the end?
It doesn't hurt, no.
So it is ok?
Can the cable portion (NOT the important antenna portion) be bent (let's say 90 degrees) without affecting range? You mentioned that the cable portion is just to transport the signal from A to B and it radiates nothing.
Yes you can bend the coax. As long as it's not kinked or deformed.
@@JoshuaBardwell thanks!
So we know what not to do. How do you install it properly.?
ruclips.net/video/KA2OLTBIjKk/видео.html
hello, I'm putting together a drone with the following components a pdb matek, a fc sp racing f3, esc hobywins.
I have everything connected and configured in betaflight, but the motor 4, when I arm and I give gas to the stick to raise this one heats up and esc also.
change engine and esc connect and the same thing keeps happening.
I need your help that may be happening ...?
What about lenght.... maths say the antenna should be 30-31mm long.. however Frsky antennas come at 34-35mm ... are they wrong? or is there something im not taking in count?
+sparrowlt they mist just be tuning to a different frequency?
Joshua Bardwell
But Frsky is suposed to work at 2.4-2.5Ghz .. if anything they should even be shorter.. thats a mystery
I would copy their antennas on the assumption that something weird is going on.
Question that will soon pay off,I have an FS A8S could i use a frsky T-shape Antenna instead of stock? ,its a bit chopped .
I know i'm digging up an older post, but what I find difficult to understand is why ie. flysky is using a lot less of a length on their antennas. I've seen 23mm and 26/27mm. Searching on the web is even more confusing as you read a lot of opinions rather than facts.
Yeah, I don't know. And people report much better range by using a proper 1/4 wavelength.
Got one antenna shorten by the propeller. What is the best way to fix it? Should I get a new one or can I strip the end to the same lenght?
+MegaMoonse You can strip it. See Bruce's video linked in the video description above.
+Joshua Bardwell Great, thanks!
I saw a video a while back that the guy said his rc club showed him a trick to get better signal, which was to bend the antenna at the end. I think though he was talking about the fpv camera`s antenna? True or false?
Thanks for the info!
+Deuts Boui_FPV360 My pleasure!
Why are the stock frsky antennas 3.3-3.5cm if the wavelength for 5.8ghz is 5.17cm?
+Ben Solwitz FrSky is operating in 2.4 GHz. That's about a 12.5 cm wavelength. The FrSky antennas are a 1/4 wavelength dipole.
+Joshua Bardwell Oh duh I forgot just the video is 5.8ghz, thanks!
hey Joshua, I'm using a frsky v8fr-ii. it's brand new, and losing signal 1-3 times per flight (at 20-60m), antennas are new from factory at a 90deg and undamaged. do I need a new receiver, or could it be something else?
It's just a matter of trial and error to see what's wrong: your receiver or your transmitter.
sharpe bending the shielded part is also bad, corners should be as rounded as possible.
Can i secure my antennae with hot glue ?
Antena rc4gs di receiver saya putus separuh.
Apakah mempengaruhi sinyal???
Dan apakah bisa diperbaiki???
yes, indeed we sub to RCModelReviews. great channel.
Suwon cak
Very helpful. You know, I know about antenna tuning, but still dont apply any knowledge to my copters. I just put that thing in the air. I broke an antenna in half,, and was going to think about soldering the missing length onto the end,, but i did not know only the tip was actually antenna. I just thought it was some longer portion of tge wave. (Well, I knew 2.4 bagiga-hz was around 12 cm, but I just figure I shouldnt question the engineering, even the cheapest crap is usually very well engineered compared to any work I might try).
how in the world can you make a dumb statement like that "i know about antenna tuning..." NO YOU DONT or you would not post such a comment
Joshua...would antennas placement work if placed underneath frame with both ends sticking out from under each back motor?
There would be a little reduction in range but it would probably still be okay.
Joshua Bardwell, Thank you.
Great information. Would heat shrink over the end cause a reduction in range?
+Dodger FPV no, because plastic is not electrically conductive. It has almost no effect on RF propagation.
+Joshua Bardwell sweet! Cheers buddy
i have a the turnigy evolution ia6c receiver the antenna is soldered in if i buy the antennas with the end on them that plug in can i just cut that off and solder it in thats all i can find for sale
Yes. But you have to know how to do it correctly. You can't just solder coax like you can hard-wire.
ok thanks
is the receiver antenna coax length critical ? i understand the antenna length but how critical is the coax length...?
Coax length doesn't matter.
+bing crosby To elaborate, coax length matters a little bit, because the coax causes some loss in signal strength. The longer the coax, the more signal is lost. But the coax length doesn't affect the tuning of the antenna like the length of the un-shielded section does. And the difference between 3" and 2" is completely trivial when you consider that the overall range of the control link is over a km. In theory, if you were trying to break range records using 2.4 GHz, you might benefit by shortening up the antenna coax length as much as possible, but for most of us, it's irrelevant.
Anyone know what the larger diameter ends are on my tgy ia10 receiver?
+Vic Prk (Slick Vic) they are the same as shown in this video, but over the ground mesh coming from the cable there goes a metal tube back over the antenna. Its also used on the linear polarised FPV antennas you get in your fpv transmitter sets, it just helps to get a better signal by making the lanth more precise. easiest thing would be, just cut open 1 unused FPV linear pol. antenna, you´ll understand once you see it ;)
+Space Explorer Thanks just wanted t know what to not cover up with something that may not be impervious to signal
Good video, but I think you missed the "why" people do it wrong. I think a lot of folks probably are under the misconception that covering the antenna portion with something non conductive like a plastic straw will kill the signal.
+Robert Baltrusch You know, I never thought of that. I have worked with RF so long that it didn't even occur to me people wouldn't know that plastic doesn't effect RF transmission.
+Joshua Bardwell Funny because when I started in this hobby, I was trying to emulate what everyone else was doing. Every 2.4 antenna I seen had the top unprotected and curled over. It seemed so delicate that I decided to cover it even if it was "wrong", thinking I was just sacrificing range for durability. But now I know! :)
+Joshua Bardwell One question I've had in the back of my mind. I don't have a fancy schmancy Taranis, I have an at9. When I learned about how to repair the antenna awhile back, I measured another RX antenna and it was 2-4mm shy of a qtr wavelength. I made it the correct size, but now I'm wondering...do some manufactures tune their radios to a little less or more than 2.4? Or is it a safe bet that every radio is supposed to be exactly 2.4? Actually, I just had a thought. Is the Antenna inside the controller the exact same? Wonder if I could open it up and make sure they match perfectly?
+Joshua Bardwell maybe you could do a video on RF transmission, and how things like carbon fiber, metal, shield/reflect the signal. Multipathing etc. Maybe show people how they can shield a part of their antenna on their frsky or other rssi enabled radio to make it directional and find a lost model using the rssi ( a trick I've showed a lot of folks at my club, and they were more than impressed.)
Chris E I would go with whatever the manufacturer decided. The tuning will typically be for the middle of the band. So the 2.4 GHz band actually goes from 2.4 to 2.5 GHZ. So the tuning of an antenna would actually be for around 2.45 GHz, which would slightly lengthen the antenna. There may be other aspects of the antenna system that affect the tuning, so the antenna element may end up being optimally tuned when it is not quite exactly a quarter, half, or full wavelength. If you have an antenna analyzer ($$$) or an RF power meter ($$) then you can test the effects of different antenna designs, but if you don't, then your best bet is to copy the factory antenna as closely as possible, on the assumption that the manufacturer probably knows what they're doing.
Do you think it's ok for me to solder my frsky UFL connectors onto the receiver so they don't come off so easily? Or should I get a hot glue gun?
I think there are probably better ways to go about it than solder. Hot glue is fine. You can just turn them 180 degrees so they lay back across the receiver, then use some electrical tape to hold them down.
I feel like such a dummy and should google some good antenna theory, but has any conclusion been reached on FrSky's apparently "wrong" length of their XSB antenna (Being different from 1/4 wavelength)? I keep seeing possible explanations, but nobody draws a conclusion. I would think I'm just missing it. I saw their coax as being an integral multiple of the wavelength (Which I thought was irrelevant in an impedance matched setup), and their antenna length was too short or long for the 1/4 wavelength typical "target". ALSO: How does the characteristic impedance of the transmission line and that of the antenna compare? The coax is going to be relatively constant over a large frequency range, while the antenna is designed for a specific narrow band of frequencies. Right? Does the antenna have a purely resistive characteristic impedance at this frequency point, that's equal to the transmission line's? That would seem to be the obvious answer. I would think the resistance of the antenna dummy loads would be that. Did I see the one you were using on the X10 as 50 ohm? I know there are antenna tuning gadgets at the source that minimize VSWR, but can this actually change the output performance of an incorrect antenna length to that of an antenna of optimal length, or is it only protecting the transmitter from reflected energy? For an RF guy these questions are probably retarded.
Just use heatshrink and a ziptie. Holds it better than anything.
Thanks for the tip!!! Any tips for improving Vtx? When flying FPV, it seems the video signal gives out long before the control signal does.
+ibfisher the video signal is much more intensive than the control signal. That's why the range is so short. There are various things you can do to improve range, but too deep a topic to discuss on mobile right now.
OK thanks anyway, cheers!
+Joshua Bardwell
are there actually any benefits of going for the lower ends of the 5.8ghz spectrum to increase range?
the 5.8g frequency is very high and the lower the frequency, the longer the wavelength and therefor the better the air "penetration" so to speak, right?
so wouldnt that in turn mean that going 5665mhz instead of 5945would yield slightly better signal strenght, at the cost of slightly higher latency?
ah, the difference would probably be imperceptible, right?
+3R45U5 Not really. The main effect of channel choice would be 1) whether there was more or less interference on that channel, including background noise, and 2) most importantly, most transmitters put out more power on some channels than on others--often a significant amount.
Josh does the diameter matter? I bought some coaxial to make fpv transmitter antenna, can I use this wire on a radio receiver? I have an orange Rx with diversity and one of them was lopped off at the plastic... so I need to shield the soldier joint somehow?
Diameter doesn't really matter. Impedance is mostly what matters.
Thank you! Impedance would be the same for 5.8 and 2.4 for radio and video?
Scratch that JOSH. I opened the case and it uses those quick disconnect pieces that are like $1 each. Not worth soldiering! Thank you for your channel, I do "lean something today". Regularly!
So the reason why my rc car has only like ten feet of range is because the antenna has been cut/modified.
Ahh I've been guilty of that. Will have to fix them up.
When you were talking about it being bent, it made me think of circular polarized antennas. Does that have any relation to it or am I just trying to hard to have big smart brain head thing.
Bending this antenna won't make it CP. But CP antennas are bent.
So can I cover the ends with something like electrical tape?
Yes.
Just curious because I don't know and have not found any results on this,
can you curl the receiver antenna like a servo wire?
It will hurt reception.
I've fixed these antennas before - and yes, removing the outer sheath and ground to expose inner signal is a pain in the ass lol
+Razor E I have pulled more antennas than you know off of X8R and D8R and D4R receivers that are either dead or that I just won't use any more. You can get replacement antennas for about $2 or less, so it's handy to have some spares around. But in a pinch, in the field, if you absolutely have to, you can get the job done with a razor knife or a delicate hand on a pair snips.
+Joshua Bardwell i hear ya. i use Spektrum but same idea. I just use lemon diversity sats now
The X8r antennas are printed circuit boards, not wires. Diversity is maximized if they are 90 degrees to each other, but it's not required. For more, see one of my earliest videos.
ruclips.net/video/JlaBpd0Rs-k/видео.html
So you can cover the whole antennae with the coffee stirrer? Or do you have to leave a 3mm length which should be ok at the end?
Right now I use frsky Xsr receivers and hot glue the base. Should I hear shrink from there to the end of the antennae or not?
+roland burrows antenna stirrer should not affect coverage.
I wonder if some of the misinterpretation is due to people being familiar with the old 27MHz band where the whole thing *is* the antenna?
+TheChipmunk2008 maybe so.
+TheChipmunk2008 maybe so.
+TheChipmunk2008 maybe so.
+TheChipmunk2008 maybe so.
TheChipmunk2008 maybay say
It's true, even I do it and I already know better! Lol
I can tell that really grinds on you doesn't it?
What about racers that tape them to the arms though? The carbon fibre (particularly if it's grounded to the fc) acts as sheilding!
But isn't the foremost thing to do is get them up and as far away from rapidly changing magnetic fields as possible?
It's a tradeoff between durability and range.
Man I'm sure you're tired of me by now but I have a question. You said if you change the length of the wire it affects tuning frequency. but at the end of the video you say it's okay to cut the end off and strip the shielding back and your good to go.
I thought you have to splice on another piece to make it the same length it was?
+Tyler McDonald The overall length of the antenna doesn't matter. What matters is the length of the exposed center lead at the end. So you can cut it off and strip back the outer sheath and shield to re-expose the correct amount of center conductor.
O okay that makes total sense now! I thought it was the overall length of the cable. Thank you so much for clarifying. I'm learning so much lately
+Tyler McDonald Thanks Bruce for fielding this one. Yes, the key part is the length of the un-shielded section. That is the section that is acting as the antenna. The whole point of the grounded shielding is to prevent the whole wire from being an antenna, and therefore, affecting the tuning.
Also just to be clear, do not try to splice antenna wire unless you really know what you're doing. It's not as simple as just soldering it together.
Not only that bent antenna is not tuned, but also changes radiation pattern. Such whiskers antennas are pretty bad, it can be improved a lot. But I will not post any link to my videos. It is really bad taste to spamming others.
if it needs to be straight - why then 5.8 circular polarizer antennas are all bended ? :)
+fpvYou Because they are circular polarized on both the transmitter and receiver. The radio transmitter antenna is linearly polarized, that's why the receiver benefits from a straight antenna as well.
+fpvYou without going into too many details, it depends in the design of the antenna. The type of antenna used in "whiskers" is a dipole, and it needs to be straight.
+Joshua Bardwell why then 2.4 PCB is the same length active element ant all wavy ? www.sequoia.co.uk/images/product/png/3375.png
+fpvYou I'm not knowledgeable enough about antenna design to tell you for sure, but I believe what you are seeing there in the "wavy" section is an impedance matching transformer. But the bottom line is this: some antennas are designed to be wavy and some antennas are designed to be curved and some are designed to be straight. But the reception and tuning of the antenna depends very critically on the antenna being as it was designed to be. Your "whisker" antenna is designed to be straight, not kinked. If it's kinked, your range is being affected. Now you may honestly never notice this, because the range of a FrSky system (for example) is so much farther than many of us ever fly. So even if you are cutting your range in half or one quarter, you may still have fine signal strength. But from the perspective of best practice, the antennas should be straight.
guilty...I'll be fixing them