3 simple tips for a clean analog FPV
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- čas přidán 5. 09. 2019
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1.13mm coax wire bit.ly/3uP6fsZ
Having a noise in #FPV video feed? Low-ESR capacitor is not helping? There is a chance, that your video noise is not really coming directly for LiPo. Maybe cables are just picking EMF interference from the air? Here are 3 simple tips on how to solve those problems: always connect grounds very close to each other, twist cables, use this coaxial wire for the video signal! - Věda a technologie
Mini Coax! Thank you! I didn't even know that existed.
Mini coax is antenna wire! An old antenna may do the job.
“I’m paweł spychalski, and your gonna learn something today.”
Hi, wanted to share some unbelievable(for me) problem that I think I just found out the cause. About 2 months ago so, I noticed that my analogue vtx was performing very very badly. The issue suddenly started to appear out of no where, and I started having the same issue with 3 of my quads. All producing bad noise to the point I can't even pilot it properly. Now this issue really brought me to the core of frustration. I rewired in every possible combination, resoldered, used lc filter, low esr, used coax cable, redundant ground, any possible method, I tried. Replaced brand new antenna, vtx, motor, fpv camera, fc, heck, I even built a brand new quad. Nothing, nothing solved the noise. Just yesterday I noticed that this noise only appears when I power on my radio, when the radio is off, my vtx transmits wonderfully. I am using elrs. So what i did today was to just lower the elrs module power output to 500mw and puff, the noise is gone. Like magic. It was unbelievable. I burned a fc, vtx, lost a whole quad, and precious time over this problem.
Also, what i don't understand is, I have a moblite 7 ELRS with the Happymodel diamond f4. And I've never had any issue with its vtx transmission even in 1 watt. Man, I hope to know the real technical reason behind this and how to actually make 1watt work without issues.
did you figure it out?
I suggest use dynamic power, to not have to blast at 500mW all the time
Nice, This is why I watch this channel. Great ideas you don't hear anywhere else. It must be because he's an engineer so you can trust him.
This is like the tip of the year I think! thanks Pawel. Ordered up a dozen metres of it
As far as I've been taught, understood and field experienced the golden rule of noise reduction is:
Ground is like your mamy ... you'll only have one !
The old engineer
Thanks for making this great video. Very informative.
Dude! Awesome tips. Thanks for posting.
Really interesting, Pawel! Great idea to use a coaxial wire! 😃
thank you very much.. last step is really work for me.. wish you all the best.
This is one of those thoughts I have had and never acted on. Because so many people focus on power I figured this idea to be wrong. Thanks for posting this. I actually purchased coax long ago to do this, now I will.
Cheers!
did you succeed?
@@flat-earther Yes but not exactly how I planned. The coax likely helped but the biggest improvement came from changing antennas. I changed both Tx and Rx antennas to 125mm lolly-pops. I also looked at the SMA connector which can have a lot more solder attaching it to the board. Originally I just thought the lolly-pop was the fix but changing 2 things at once always levels you guessing. I added the solder because I was concerned the long antenna would pull the SMA connector off the VTX. In that process of re-soldering it did appear the amount of solder on this connector was very inadequate. When you check your VTX next, see how well your MMCX or SMA connectors are soldered on.
Thanks for this. Shielding and "star" grounding to eliminate ground loops. Of course. Twisting wires I like but tiny coax I love. Maybe some tiny bits of copper foil also. Your channel is essential.
Great tips! Thank you!!
I had considered doing this with mine a while back, but assumed it would just be Overkill. Definitely gonna try it out now
Good tips, i going to try it.
Wow great tip thank you!
I've just built a 6 inch quad , And it had slight ones in the FPV monitor , I slid some Ferrite beads over the power wires from the the vtx to F.C and also a couple onto the video wire from the vtx to F.C ....it cured the problem dead , I'm amazed we don't have a lot more RF type noise with our quads as most have very little or No real screening at all ( I'm an RF engineer ) ....You mentioned coax , This is a very good way to deal with interference issues , Mini coax is ideal ... One ground is also the way to go , You don't want Daisy chain grounds causing ground loops.
bought!, great solution...Thanks
thank you .it really helped
Thanks. It works great. Greetings from Russia!
Thank u that was very helpful
Co ax ....didnt even think about that.
Very nice.
you save my life friend!!!!
cool!
You can use USB cable, it is always shielded. Just connect shield to ground.
The thin coax idea is a good one, thanks. Do you star GND even when powering the VTX with vbat directly from the battery terminals but the camera from the 5V BEC on the FC?
I tried the link to caox cable, but couldn´t find it
On your coax wire solution, is the shield wire connecting VTX & FC grounds or is it just grounded on one end (looks like VTX side in the video).
One more thing to check when there is video noise related with throttle - check bolts that mount motors with corresponding ESC pad for continuity. While mounting motors I have connected one bolt with loose wire from motor by mistake, in result there was terrible noise that couldn't be reduced.
Hey THANK YOU for this!! Can you help me explain though! So how do you have that co aux soldered in there? The internal going from vtx to fc correct? Then I see there is double ends? "A splice with two diff solder locations". Did you solder the drain wire to ground then on both sides? Thanks fella!!!
coax cable has essential 2 cables, its a normal single core cable with insulation, wrapped round that cable is a grounding sheath, its normally braided to cover the etire diameter, its a bit tricky to strip back because dont want to cut through the shield, you strip back just the outside insulation to reveal the ground, unrap it from the internal cable and then strip that to get your signal wire.
attach the signal wire to the video out, and the ground to the ground on fc, do same at the vtx, signal wire to video in on vtx and the ground sheath to ground.
Nice one, I was wondering about mini coax for signal shielding years ago but some people on rcgroups convinced me it was overkill. Is it the same stuff the normal 2.4ghz receiver antennas are made from?
I would say:
1: Lipo batteries are not that noisy IMO, despite what many of the recommendations claim. My idea of noisy is ripple presented in switching supplies. I'm not too concerned about a Lipo since it can deliver high peak currents and is about as smooth a supply as you can get outside of a linear regulator, but the loads being supplied by that Lipo are the actual concern because they create noise. The adding of a capacitor is about as far as I ever see the tip go, but I'd say it would make sense to not only add a DC reservoir capacitor on the supply rails, but also any necessary decoupling capacitors directly on IC's which are not yet protected. Those would be something like small ceramics around 100nF to 1uF or so.
2: Supply the vtx from a source isolated from the supply the motors are on. To me this is where the 'noise' comes from in the Lipo. If the VTX is on the same source as the motors then you are certainly dealing with line noise. Then physically shielding the motor cables should actually help block the fields.
3: Good wire management as you mention. Crossing wires and untwisted pairs with no shielding is always problematic even at simple audible frequencies. The key phrase there is "twisted pairs" as the point is to cancel out the fields in the pair, which should be equal and opposing among them.
thanks for your insight.
BTW magneticitist, have you become a flat earther yet? If not I suggest viewing the 13 part series _what on earth happened_ in my about to learn how the earth is not a globe
I was wondering about the coax connecting myself. I'm liking that idea a lot what did you connect it to. I have some old pigtails I can maybe use also just clip them but not sure which part I'm soldering. The ground cable? Signal or power or all lol using coax
Great video - I'm pretty sure that this is the solution to my current video noise issues.
I just don't understand one important aspect of your solution, and in the comments it seems that I am not alone.
Do you connect the outer shielding of the coax to a ground pad? That's what it looks like but to a newb like myself I want to be CERTAIN.
Thanks Pawel
BTW could I repurpose an existing broken rx antenna instead of buying coax?
Did you make a build video of this quad? If so please share the link. I have a source one 7in and my video use to be Perfect... with a rushfpv mini tank vtx matched with runcam Phoenix camera.
Hey Pawel I cant see to clearly but need to try that buecause im having video drop out and noise i have crossfire and i can not go far at all please help...
Great tips. What's that blue wire with the connector in the middle of it for? Thanks.
If you are talking about the camera it is built in cam osd. Nothing to do with fc osd. You can change the RunCam logo show cam voltage or screen ratio - 4:3 or 16:9 or put custom text on the screen. You connect a 5 button remote control with it and need some way to display the output while adjusting it.
thanks !!!
Thx!
Thanks for these tips. 😁 I have the problem with 2 new quads in 6S. I thought it was the cam (same on both). I’ll try the coax solution. 👍🏻
By the way, do you have a video of your showed build? It seems you have VTX/RX in double (or maybe just the antennas?)
DVR is here czcams.com/video/M49nfgjMYcg/video.html . Single VTX and single RX
I think you should do a comparison to prove the effect of that...
And I think just the positive and negative wires have to be twisted to cancel each other, if you twist the signal with the + and - you are doing nothing
I cant tell in the video but I just have to ask. You solder both the active and ground element of the Coax to the fc video out pad to thw video in pad to the vtx right? Or you just soldered the middle wire of the coax and left the ground tucked in. Im having trouble solving my video also. I did the capacitor already, lc filter and twisted all the wires and still noise when throttling.
Both sides of coax shield soldered to GND
@@FPVUniversity Thanks sir Pawel! Will update if, it makes a difference
Shouldn't you only ground one side of the shield so as not to create a ground loop?
Coax cable for ground only. For plus you are using regular soft isolated wire, isn't it?
I still don't get how to wire the coax. I should solder it to the ground but in the video I see to separate cables from the coax soldered to 2 different solder pads, at least I think that's what I see 🤣. Could someone clear this out for me?
it took JB 2 years to figure this out and put out a video :)
Thanks Pawel I've got some black Diagonal lines that are driving me nuts
If I use a coaxial cable in place of a regular silicone wire, do I solder it the same way? Or is there a special way to solder coaxial cables? Thanks!
Soldering is the same. Only you have to solder both shield and signal part. Signal to signal, shield to ground on both sides
@@FPVUniversity Thanks!
WHERE did you get that tiny coax? I need it for my guitar wiring as well. I can only find like 24 or 26 awg.
There is a link in the description bit.ly/3uP6fsZ
best practice:
1)cam to the onboard 5 v bec, vtx - to the onboard 9v bec
2)if it is only 5v bec and your vtx supports 5v - connect both to the same bec
3)if your vtx doesnt, then connect it to the vcc pads, a cam - to the 5v bec of your vtx. do not add any additional ground wires to a cam - it usually adds noise under throttle punches ( but, yeah, eliminates osd flicker (better add some decent big cap like 1500uf on power leads))
4)never connect a camera to vcc pads (always adds diagonal noise, lines under throttle punches, etc)!
5)dont buy matek vtx - the shittiest vtx in the world (susceptible to the noise from frsky telemetry if connected to a onboard bec, slow channel and power switching via tramp)
I've had the matek hv vtx for over 12 months its been great
@@llickmogan that means nothing tbh
@@MrBirdshell666 whatever
So just replacing the normal wire to coax of vtx(gnd and vid) will fix it? T.i.a.
Hello Pawel! Nice tips товариш, but the coax cable it for Ground and signal, and the suplly is a normal wire?
greetings from Brazil!
You could use coax wires at the camera output (from camera to flight controller),too, couldn‘t you? At least for video and power.
Hi Pawel, Im looking for a solution for my video noise. My video is clean but when I turn on my radio (x9d) I get lines in my video. Have you seen this before? Thank you Pawell ✌️
I’m struggling with bad video too. It’s a little hard to tell, but are you using vbat to supply power to both vtx and cam?
yes
Where do you get your Coax cable from?
my image comes with black static dashes and seems do not come from the camera but from FC. Do you know what could be?
Have you uploaded latest fonts?
Is this 50 or 75 ohm coax. I guess you need to use 75 ohm for video signal right?
I'm gunna try this my matek f7 se and matek hv is getting bull noise ive cleared it up nearly 100% just got the diangonal faint lines still
Hi Pawel. Off topic Again! I have looked in the Inav wiki and cannot find reference to gps type camera triggering. Is this likely to be coming or is it a bit "ardupilot"?
there is no camera trigger
@@FPVUniversity Thanks Pawel. Happy flying!
This is the coax cable your looking for on Amazon US. Just cut the ends off and cut to length.
uxcell U.FL To Extended SMA Female Connector RF Coaxial Adapter RF1.13 Wire 20inch Length
can u tell me the name of the caox cable? i can't find one wire coax cable.
bit.ly/3uP6fsZ
@@FPVUniversity thank you!
Sorry, when i click on the link for the cable i read 50 ohm... what it means? that the cable have 50ohm?
That's the cable impedance. It's supposed to say that. You might want to watch this czcams.com/video/9QzujzJCnTY/video.html
@@FPVUniversity thanks!!
Paweł, gdzie można znaleźć taki kabel koaxialny, szukam na allegro, i jakos nic mi ciekawego nie wyskakuje
bit.ly/3uP6fsZ
Bo w PL posucha
I swear every CZcamsr fights with auto-focus...can't these giant tech companies solve this?
Nice one Pawel! Coax can clean up a little spaghetti too. I have to ask, where did you get hold of that cable?
The first link in a description mate
@@FPVUniversity Thanx, overlooked that :)
What size is that? 0.81mm? 1.13mm? Or 1.37mm?
BTW, all those crossfire antennas that you don’t use are made from mini coax too 😉
yeap
Gideon FPV Perfect! That's exactly what I wanted to ask.
Ah, micro coax cable, of course, nice tip Pawel....This is what they make 2.4G RX antennas with too..?
yes, the same
@@FPVUniversity cool..see if I can get it off E-Bay....Thanks..
It was hard to follow for me. Maybe because your English is a little rough maybe. ? Idk. So I'm getting lots of snow static in my video feed . Where should I run my grounds too? Please help. No one else will respond and I need to make some more videos for my channel.
solder camera ground ,vtx ground and all other cables not being use to the same ground pad!!
u might be on to something here xD
So I guess powering your camera from the VTX does not count as a common ground?
I have this same question
Looks like RG-174/U Coax Cable, very thin.
No, this is not RG-174/U. It's only 1.1mm thick so less the thickness of RG-174
@@FPVUniversity Link please ....
TNK
The old engineer
@@tulliobonfiglio Read the description
Any vendor in Europe ??? :-( :-(
Dont want to wait like 4 weeks on Ali slow :-( :-(
@@chattonlad9382 Read and opened quadmeup ... found many things but not this cable. I sign as an old engineer as a matter of fact, isn't it ?
TNK
The old engineer
so we could just use coax everywhere
not that it makes sense everywhere
I could not stand it so ...... muted and turned on subs :)
Where are you from mate ?
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