RF power versus antenna gain (the results may shock you)
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- Опубліковано 23 лис 2024
- Today I talk about RF power versus antenna gain for FPV systems on RC planes and drones -- the results may shock you. Another whiteboard video with some "in the field" footage to prove the point.
Here is an earlier video which explains how antenna gain works:
• FPV antenna gain and r...
Almost to the limits of visual line of sight.. lol love it.
That cracked me up ahah
Get in there Bruce! Your audience loves you and speaking as an electrical engineer, your videos are the best and most informative video's on youtube.
I'm not an engineer, but I couldn't agree with you more. Invaluable knowledge for free. How no to love it?
This vid is exactly what I needed to clearly understand how this works. Thanks for the detailed but not overly complex tutorial!
Bruce, this may be the best side by side comparison I have seen. So many things we do make just little differences. Like the antenna test I just did. But your test here very clearly shows the difference. Would love to seen done with some more antenna.
HELLO, DoneRacer101!
Bruce, you're the professor I wish I had in college. What a great job. Thank you.
Bruce you are the best.Better then the rest.No matter what they say.Thank you!I think we need to educate ourselves on the subject of frequencies in order to keep the hobbyist of FPV alive.Thank you!
thank you...i learned something: isotropic antenna and why u need it. And your presentation is very addictive, the more I listen the more question I have, and leading to me listening more of it.
Bruce, can i adopt you to be my grandfather
I don't have an RC plane/drone, but still found this really helpful for general RF theory. Thank you for uploading
Thank you Bruce! Once again. This hobby would not be the same without you and all you do for the community
Excellent demonstration of the distribution of transmitter power when using omni directional anntennas.
I'm not a RC person (yet), but I'm learning to get my HAM license, so these videos help me a lot, thanks professor!
That’s why I’m here and his instruction is invaluable!
This guy should be teaching classes! Great energy and inspiring way to teach.
I am a short wave DXer. So I find your dissertation on RF propagation to be informative. Please continue.
This so true
I changed my quad vtx because become defective. So I decided to buy one that is 500mw( the old one was 100 mw) and I don't feel any real gain ( only more heat ) Antenna is most important
Thanks for great information
The fcc is after hobbyking for selling transmitters that produce power levels beyond 1w (1000mw) and can broadcast on non approved frequencies. The majority of us purchase and use products with in the the fcc limits. It is a thing but not the end of the world thing for most of us.
Bruce, you're awesome.
I’m about to start my junior year for Electrical Engineering with a focus on RF. These are great videos, thanks!
Great information! I typically use a 50mw SP Antenna on the transmitter an receiver and fly close proximity (within 200m) and very rarely get video drop-outs. Yes, I would much rather use a better antenna and save that battery power for flight. Thanks for the video and Happy Flying!
Thanks some of the best explanation of antenna theory and practice also applicable outside of the RC hobby
Videos like this are what have kept me watching your channel. Learning physics and electronics in such a practical application way is inspiring. Thank you.
The use of balloons in this video is genius.
I wish he used balloons filled with hydrogen, though.
I agree, using balloons to explain the inverse square law is a stroke of genius!
@@rivrunner1 I agree, it was an excellent demonstration. I did wonder what the balloon resistance to being inflated did as it was increasingly pressurized, I imagine it went up, but I don't think the results would have been much different if it had been linear.
This is the moment i've been waiting for bruce to explain between power and gain... nice one bruce!
LOVE a good white board video in the morning.....All right.... got my tea... ready.....Got it Bruce.... Thanks Mate...
Great video Bruce! Glad you made it back to the whiteboard - I’m using two five-turn helicals on my diversity goggles - pointed about 60 degrees away from each other. Marvelous range and coverage!!!
Waiting in anticipation for the DIY Helical antenna build Video.
Mate thanks for all this information! Fellow NZ fpv'er here 🖖😌👌 may the force be with you! Always
Great timing. My group is currently trying to get our best signals and powers so we can fly together. As one of the guys tasked with understanding this stuff, your videos lay it out in a way I can understand. Thanks Bruce !!
I am able to understand your concepts since I am a licensed aeronautical radiotelephone (restricted) user and I have studied various concepts related to radios. I also have a lot of interest in networking.
Bruce you are an incredible teacher
Great video, perfect balance between technical information and practical explanations. Now I understand much better about antennas!
Thank you for your explanation. I've been trying to understand this for awhile in been looking at videos that do not explain it the way you do.
This is great Bruce. I admit I was power hungry, this really puts it into perspective.
Thanks for everything you do Bruce your the reason I got into this hobby. Keep on kicking
Theory is always good, I've learned something new today. Thanks Bruce!
Brilliant discussion, Bruce! Thank you!
As always Bruce another amazingly informative video. Thank you so much for everything you do for this hobby and in sharing all your knowledge and experience. Long may it continue xx
Thank you for sharing this valuable knowledge with us, Bruce! Now this is exactly why I like your channel so much!
the antenna was the problem the whole time! dang... i could never get far with my 200mw setup, but i was running an omni on my rx... if/when i get back into rc flight, ill have to get a helical and see (haha) what difference it makes :) cheers Bruce! thanks for the video!
Yes yes yes!!! I understand now what to look for when buying/making antennas and it wasn’t that hard to understand....now I’m off to your other video on how to make and antenna
Bruce is a genius! Best educational videos on the tubes
You just taught me a lot of important things that I never heard of, but really needed to know. Thank you!
Great to have you back looking forward to the build video.
Hi Bruce again! I can added to your theoretical issue with a practical recommendations... Very reasonable change the 'clever' antenna as VTX for FPV quad) to this 'moderm' antenna: 'Realacc UXII 5.8G 1.6dBi RHCP/LHCP TX/RX FPV Antenna' or 'Realacc RHCP Super mini UXII Stubby 5.8GHz 1.6dBi FPV Antenna' (see on banggood, for example). I think cost = $7 is reasonable for... /This antenna are 'Archimedean spiral' for cause 3D of geometry. It's best!/ Good luck
Great Video Bruce, now looking forward to your build video of those two antennae.
Bruce without you we would be sheep following the crowd thank you for this fantastic video again you make this hobby so much easier to get a fantastic result 👍🏻👍🏻and you 🤘🏻🤘🏻🤘🏻🤘🏻🤘🏻
I am excited to learn more and build. Can't wait. Thanks Bruce!
Great videos! helped me understand the remote control system used on the locomotives I work on as I am an electrician with no RF background knowledge !
A 360 swivel mount on the bottom of the craft to hold a directional antenna that was controlled to always point at home.
Great video Bruce - white board power!
Cant wait to build the helical antenna
Great video as always ! Keep up the good work.
Another awesome white board lesson. Thanks Bruce.
Love the balloon analogy!!
Im looking forward to making my own! Thanks Bruce!
Bruce...from North Carolina/Puerto Rico....thank you.!! amazing video.
That was a very educational video Bruce I look forward's to the antenna build thanks
Bring on the antenna build video!! Also, can you do a vid on the ways in which objects between the vtx and rx affect the video reception and how best to overcome them?
Very informative, thanks for the video. Looking forward to the DIY helical antenna video.
This is such a great video! I can't believe there are dingbats out there who disliked it. What is there to dislike? Someone is taking their time to educate and explain (really well!) a fairly complex area of RF communications. Well done mate and thank you. Looking forward to more videos!
Did you do something different with your hair Bruce? You are a legend, you make everything straightforward. I've tried to watch Justin Bardwell. I haven't a clue what he's on about most of the time.
Oh my god! I learn something today. Your explanation is simple and neat. I see you got a lot of explanation video and I'm going to watch one by one definitely. Thank you for your effort!
That's the best lecture in my life! Wish you were my teacher at the university!
Excellent video. I've heard plenty on helical's, but never explained as well as you have! I'm just getting into fpv and I probably have one of those HK vtx's in question, although I do believe it can be set to a lower power to keep things "under the radar"
Best teacher ever! Greetz from Germany 🙂
Looking forward to the antenna build!👍🛩🛠
8:15 "...so long as the antenna is pointed at your model" And THAT is the big problem with antenna gain. You have to point it very accurately to get good performance. I know, from having flown with just patches on my goggles for the past few months. I end up spending so much concentration keeping my goggles pointed at the quad that I struggle to focus on actually flying the quad. And every now and then I forget and drop my head a few degrees and suddenly I've lost video - and that's the thing too - his diagram is a 2D top-down drawing. But vertical is harder to keep stable. This is why the DJI FPV system has omni antennas and transmits 700mW of power.
I'll be waiting for that antenna build video. Great video and explanation.
I seriously need to design you a housing for those antennas... Great video!
Excellent demonstration.
This is great! New to the hobby, and I was wondering if people made home-brew antennas, like in the ham HF world. I'd love to build one. Been stringing wire in trees for 35 plus years. Love it. Thanks!
Yes I have been building some of my fpv antennas for some years. The circular polariced antennas are not that easy to build but it's fun to do 😀 there are very good build guides written by ibcrazy on the fpvlab forum (e.g. Cloverleaf build tutorial)
Hi,
Did you finally manage to build a good antenna and did it work?
Cool! I understand more and more what I really need. Thank you very much!
Great as usual ! Can't wait to make my own helical antenna !
I love the video, but really, we’re adding more power to punch through solid objects since 5.8GHz is a very high frequency. More power means more energy punching through something. It’s not really for range, but rather for effectiveness at getting from point A to point B. You don’t want a lot of power when you’re out in the open air, but let’s say you’re flying around a building at the same range, in this case, you need more power since most of it will be absorbed by that building.
And raising the gain increases power, but loses Omni-directional... the building will just reflect the focused energy in other directions instead of saturating that area with higher power for the few chance of hitting your receiving antenna.
Basically, it’s risky to fly with low power and high gain because of the chance of too many black-outs causing crashes... unless you have an antenna tracker or an observer to adjust your antenna base to move your antenna towards the aircraft.
I wouldn’t use goggles without a visual observer when flying low power/high gain because you’re going to experience constant black-outs in busy areas.
other way to think is that the transmitter is a dot, and it's power is distributed on a surface of a sphere. that is 4πr², so here comes that for a double radius (distance) , the surface is quadrupled
Cant wait for the how to video! I would like build one today. Thank you..
I fly model rockets, but your info is grand, Bruce!
Bruce, How about considering a video on the theory (magnetic/electric field attenuation) behind twisting or braiding wire leads and when it is appropriate? For example, battery to ESCs, servo leads to servos, servo leads to ESCs, brushless motor leads, video/audio power and signal, telemetry leads, Rx to flight controller (various protocols). Also, usefulness of shielding, etc. There is a lot of conflicting information out there (and,I suspect, mythology). I would respect your opinion as authoritative.
All very good. One point tat wasn't touched on with higher power transmitters is the USE more power and effect battery life. Last thing you'd want is getting that long range (out of sight) and have your battery die. I'd have the controls and video on separate batteries, weight permitting
Excellent video Bruce. You deserve a subscription. I'm keen for that helical build video!
Looking forward to the build video! Great job as always and thank you
This channel is everything I was looking for and more.
Just because of you I will give a try to to this anntena, as you said before I might end up looking weird but worth it
Thankyou for being in this hobby
Love learning from you Bruce. Can't wait to build a helical with you!
Hi Bruce, Its been about a year since I was watching your videos but got back into quads this summer. Another great video and glad to see you are busy flying as always. Thanks again !
Also I love that you have a 'head tracking head' 10:40
Thanks for another great whiteboard video! Even though I was already aware of the content this time, it was still amusing as always.
Yes a great man indeed,i have learnt so much from him......love ya bruce.
I have always been curious and intrigued by the prospect of having high gain directional antennas with some sort of computer chip driven servos that automatically aim the antennas (perhaps even both the transmitter and receiver alike) & keep the beam on the highest signal gain possible between the two. Perhaps they could use GPS to constantly relay back and forth using a fraction of their bandwidth to relay their positions to each other or perhaps they could use some kind of gain algorithm to point them in the best direction to maximize their signal or perhaps a combination of both. I have also wondered if there were some kind of way to create some form of "solid state" high gain directional antenna system which have no moving parts to electronically "point" an antenna or a combination of antennas set inside a sphere or cylinder to some direction. Even beyond this perhaps there is some way to use high power intermittent very short pulses to transmit some form of location coordinates back and forth between two antennas while using the high gain of both to transmit video. This would be in case the antennas became totally un-synced and needed to sync up again.
Hello from California! Great information and video. Thank you so much.
VERY informative I really like this type of videos you make
hi Bruce, i was browsing to web and came across the "Hawkeye Tomahawk Backfire 5.8GHz 12DBi Mini Panel Antenna" on hobbyking. it claims to have a 175° horizontal and a 60°vertical beam width. how does that work since it is a 12DBi antenna and has a much wider beam width compared to other gain antennas. keep up the good work ;)
Sir, your videos are awesome! Do you have a video about dB? People would love it!!!! I'm pausing this one and watching the antenna gain one first. Thanks!!!
You sir deserve an Oscar
Bruce, when you do your follow up to this video, are you able to talk about how the different environments (eg weather) affect the range of different antennae?
I would use this as an example of the differences between using high power transmission versus high gain directional antennas to my fellow students if I was still studying my radio theory. Still an excellent example to show a layperson or an engineer. I should say nobody stops learning 😉
I like the balloon analogy relating to the low gain antenna. Using a 2.4ghz Tx as most of us modelers do to control control our models, I was wondering if you could please shed some light on the dangers if any that we may need consider to our person, in holding what is essentially a microwave transmitter near to our vital organs and in some cases testicles for those not using a neck strap?
I love the white board ! ...& Bruce is likeable as well.
Top video bruce.
I have a question though.
Why do we not have pagoda/cloverleaf or helical antennas for our radio control transmitters and recievers?
The reason is that it isn't needed. The video feed is sending a lot of data over the airwaves and if any part is corrupted then you see the distortion. It doesn't take much interference for the picture to be terrible. A radio link is sending a much smaller amount of information very quickly and if one part becomes corrupted it just throws that data away and falls back on previous uncorrupted data. So say your sending a message 10 times a second, even if only one of those makes it through it would still be representive of what the drone was supposed to do during that one second. Now there are times where a directional antenna is used for the radio link but that is normally only for long range flying because the systems we use have plenty of range for our use. I hope this answered you question. Happy flying.
So what is the best helical antenna to use, Bruce. Great vid, keep up the good work.
Bruce. What did you mean the FCC is cracking down on frequencies? Are they outlawing, like, 900 or 433?
What a very good job you did here!!!