What a great video. I will be going through all my models and fixing my antennas. (removing bends, adjusting placement and removing heat shrink that I used to protect them)
Thank you for this information. I have various no name replacement antennas with ufl plugs and also without plugs for direct soldering for my various receivers. With these antennas, the active elements are longer than those built into the receiver. If I have understood correctly, can I simply shorten these active elements to the length of the original antenna? What influence does the diameter of the active element have?
@@FPVUniversity really? but perhaps they have idea that antenna is the part of the router as the "door" so the router can transmit and receiv the signal itself.
Great video! Would be great to know what size to cut replacement antennas for our receivers. So far no one has been able to give a scientifically satisfactory answer.
I can not give you that answer because it all depends and the antenna materials, how receiver is constructed and so on. Assuming receiver itself is "neutral", then 90% of the c/f seems to be universal value. So around 28mm. But it really all depends
So conclusion is still that FrSky have shipped wrong antennas, it's just that the bad stuff is the x4r-sb and not on the xsr etc... Is it really true that the transfer of the signal into space is best when the antenna is perfectly tuned? Say that we have a singularity sized Vector Impedance Analyzer... the antenna itself would present a larger part than the ground plane of the analyzer and so the whole equation would be thrown of the planet. This happens in reality too, although it presents a less significant part of the problem. And it happens in the aircraft too. So obviously each installation would benefit slightly from being individually tuned based on actual radiated signal measurements... All for those who cares about details.
w praktyce i tak wszyscy pchają anteny w termokurcze, a wtedy współczynnik skrócenia się zmienia i z dobrej anteny robi się gówno (a rozstrojona może wejść w pasmo). dodatkowo przeciwwaga z carbonu też nie pomaga:-(
Hello Pawel! Does the non active cable length matter? I wanna to make some pigtails on 2.4G and also on 5.8g and I am wondering how long I need to make them. Thanx!
Hmm, I am planning ordering the below. They seem to be crimped on the standard silver antenna coax: www.banggood.com/RP-SMA-Female-To-U_FL-IPX-1_13-Pigtail-Cable-20cm-p-923077.html?rmmds=mywishlist&cur_warehouse=CN
many people use the zip ties or plastic tubes to mount the antennas at their copters. What would be a reasonable approach for velocity for the coax cable including the teflon insulation and this plastic material?
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What a great video. I will be going through all my models and fixing my antennas. (removing bends, adjusting placement and removing heat shrink that I used to protect them)
I like this kind of vids ! Thx for info based on science not empty words
Great video. I love the experimental part as it simply shows your points!
Beautifully done Pawel.
Thank you for this information. I have various no name replacement antennas with ufl plugs and also without plugs for direct soldering for my various receivers. With these antennas, the active elements are longer than those built into the receiver. If I have understood correctly, can I simply shorten these active elements to the length of the original antenna? What influence does the diameter of the active element have?
I like your video. Thanks for making it.
great! but most of wifi users prefer to use sectorlal/patch or even biquad antena, what do you think?
Who are 'most'? Most users have no idea what antenna is ;)
@@FPVUniversity really? but perhaps they have idea that antenna is the part of the router as the "door" so the router can transmit and receiv the signal itself.
love your explainations
Great video! Would be great to know what size to cut replacement antennas for our receivers. So far no one has been able to give a scientifically satisfactory answer.
I can not give you that answer because it all depends and the antenna materials, how receiver is constructed and so on. Assuming receiver itself is "neutral", then 90% of the c/f seems to be universal value. So around 28mm. But it really all depends
So conclusion is still that FrSky have shipped wrong antennas, it's just that the bad stuff is the x4r-sb and not on the xsr etc...
Is it really true that the transfer of the signal into space is best when the antenna is perfectly tuned?
Say that we have a singularity sized Vector Impedance Analyzer... the antenna itself would present a larger part than the ground plane of the analyzer and so the whole equation would be thrown of the planet. This happens in reality too, although it presents a less significant part of the problem. And it happens in the aircraft too. So obviously each installation would benefit slightly from being individually tuned based on actual radiated signal measurements... All for those who cares about details.
Once again it's not that simple. X4R-SB might have some extra capacitance in the feed line and that requires longer active part of the antenna.
w praktyce i tak wszyscy pchają anteny w termokurcze, a wtedy współczynnik skrócenia się zmienia i z dobrej anteny robi się gówno (a rozstrojona może wejść w pasmo). dodatkowo przeciwwaga z carbonu też nie pomaga:-(
interesujące. jestem ZA
Yes we wan't more of this, maybe some explenation about how helical or cloverleaf antennas works ?
I wish I knew ;)
If its a 5.8G antenna, then the short answer is invariably badly.....because they are nearly always dimensionally inaccurate.
Yes, more!
So what's good length of antenna for the frysky rxsr 27.6mm? Great video
somewhere between 27 and 29mm yes
@@FPVUniversity thnk u
Hello Pawel! Does the non active cable length matter? I wanna to make some pigtails on 2.4G and also on 5.8g and I am wondering how long I need to make them. Thanx!
yes it does. Laymans terms: lemgth should be a multiple of half wavelength in coax. So: multiply of Veloticy_factor * C / f
Thanks for the swift reply! It kinda bothers me how could I find out the velocity factor of a chinese coax.
if it has a name like RG174 RG178 RG316 then should be easily findable. If not, then usually between 65-75%. Use 70% when in doubt
Hmm, I am planning ordering the below. They seem to be crimped on the standard silver antenna coax:
www.banggood.com/RP-SMA-Female-To-U_FL-IPX-1_13-Pigtail-Cable-20cm-p-923077.html?rmmds=mywishlist&cur_warehouse=CN
well, you have to assume that someone computed it correctly :)
Why do you use 'Arrivederci' :-) ??? Are you in Italy ??
Nope. At the moment Germany ;)
I mount my antenna on zip ties would they effect it
Their effect is very little and it is fine to use them
What if you don't hold the carbon spar with hands?
effect would be smaller
Paweł Spychalski Yes :) worth a try in the next video
Paweł Spychalski Yes :) worth a try in the next video
many people use the zip ties or plastic tubes to mount the antennas at their copters. What would be a reasonable approach for velocity for the coax cable including the teflon insulation and this plastic material?
those things affects VF in a very very little way. It's fine to use them
Now modify a XSR antenna and show us DVR RSSI difference :)
I'm not saying that 27 is correct. I'm only saying that saying "31.25 FTW" is not correct ;)
Fook yeah!!