Noël said:Some good reading material here about Omni Antenna vs. Directional Antenna.
http://www.cisco.com/en/US/tech/tk722/t ... 34d3.shtml
The this image below does explain everything in one go.
Great post, very well explained.
More powerfull repeater?
- Thread starter uncle fester
- Start date
Great post, very well explained.
oukenfold said:
That's the million dollar question. Several members have posted thoughts or intentions of cracking open the camera. Let's see who has the balls to do it.
The easy way to understand antenna "gain".
The transmitter tries to send Radio Frequency energy out (broadcasting), with the goal of
getting "enough" usable energy to the receiver, usually a very, very small fraction of what
was sent.
For comparisons, a "perfect" theoretical antenna, which radiates all the energy it gets,
and sends all that energy uniformly in ALL directions, is used. Think of a light source
in the center of a sphere, with dim illumination all over the inside surface of the sphere.
DISTANCE: Make the sphere twice (2x) as big, and the inside area of the sphere is FOUR times
larger. With the same energy being sent out to cover the 4-times greater area, the
local brightness is just one quarter of what the surface of the smaller (1x) sphere experienced.
POWER: To make the local brightness on the 2x sphere the same as we had on
the surface of the 1x sphere, we need 4x the power.
The Antenna Gain:
Let's imagine that we put a moderately large flat mirror under the light, reflecting
all (most of) the downward going light upward, then the bottom half of the sphere
goes dark, and the upper half is twice as bright. The mirror is acting as an "antenna"
not wasting the downward light, sending it in a useful direction, thus a 2x "gain"
achieved with "smoke and mirrors", without the smoke.
Armed with this concept, if our receiver was always on one side if us,
we could add a second mirror, vertical, on the side of the light away from the
receiver, and half if the lighted hemisphere would "go dark", and we would
have 4x the light at the receiver. We would have given up the omnidirectional
light radiation for a "directional" illumination. However, we are still lighting
a huge area compared to just lighting the pages of a book that we want to read.
Add more mirrors, shaped somewhat like a dish, and we can easily make the
light on the pages of our book 1000 times brighter, allowing us to read with
only candle power, like a spot light. But, if the book is moving around, we might
have trouble keeping it illuminated by pointing the antenna correctly.
If an antenna does not send out all of the energy, it is said to be mismatched
with the transmitter, or there are other problems, but we will ignore these issues
for the sake of simplicity.
So, sending the energy wisely, in the directions we find useful, without making
the "beam" too narrow or the antenna too large or expensive, is the goal.
A different antenna, like the vertical RC Controller antenna, radiates in all the
sideways directions, but not much up or down. As the antenna gets more
directional (more narrow "beam" or radiation pattern), the effective "brightness"
(RF energy level for the receiver) increases, as long as we keep the receiver
"illuminated".
The transmitter tries to send Radio Frequency energy out (broadcasting), with the goal of
getting "enough" usable energy to the receiver, usually a very, very small fraction of what
was sent.
For comparisons, a "perfect" theoretical antenna, which radiates all the energy it gets,
and sends all that energy uniformly in ALL directions, is used. Think of a light source
in the center of a sphere, with dim illumination all over the inside surface of the sphere.
DISTANCE: Make the sphere twice (2x) as big, and the inside area of the sphere is FOUR times
larger. With the same energy being sent out to cover the 4-times greater area, the
local brightness is just one quarter of what the surface of the smaller (1x) sphere experienced.
POWER: To make the local brightness on the 2x sphere the same as we had on
the surface of the 1x sphere, we need 4x the power.
The Antenna Gain:
Let's imagine that we put a moderately large flat mirror under the light, reflecting
all (most of) the downward going light upward, then the bottom half of the sphere
goes dark, and the upper half is twice as bright. The mirror is acting as an "antenna"
not wasting the downward light, sending it in a useful direction, thus a 2x "gain"
achieved with "smoke and mirrors", without the smoke.
Armed with this concept, if our receiver was always on one side if us,
we could add a second mirror, vertical, on the side of the light away from the
receiver, and half if the lighted hemisphere would "go dark", and we would
have 4x the light at the receiver. We would have given up the omnidirectional
light radiation for a "directional" illumination. However, we are still lighting
a huge area compared to just lighting the pages of a book that we want to read.
Add more mirrors, shaped somewhat like a dish, and we can easily make the
light on the pages of our book 1000 times brighter, allowing us to read with
only candle power, like a spot light. But, if the book is moving around, we might
have trouble keeping it illuminated by pointing the antenna correctly.
If an antenna does not send out all of the energy, it is said to be mismatched
with the transmitter, or there are other problems, but we will ignore these issues
for the sake of simplicity.
So, sending the energy wisely, in the directions we find useful, without making
the "beam" too narrow or the antenna too large or expensive, is the goal.
A different antenna, like the vertical RC Controller antenna, radiates in all the
sideways directions, but not much up or down. As the antenna gets more
directional (more narrow "beam" or radiation pattern), the effective "brightness"
(RF energy level for the receiver) increases, as long as we keep the receiver
"illuminated".
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Had a crash recently that bumped my camera's bezel out of whack. While opening it up to straighten it I took a photo of the inside of the camera. Looks like we have antennae on each side connected with U.FL Mini PCI pigtails.
Gonna hook up a TP-LINK TL-ANT2414A on each side of the camera
Gonna hook up a TP-LINK TL-ANT2414A on each side of the camera
Attachments
ZonComGMZ said:Had a crash recently that bumped my camera's bezel out of whack. While opening it up to straighten it I took a photo of the inside of the camera. Looks like we have antennae on each side connected with U.FL Mini PCI pigtails.
Gonna hook up a TP-LINK TL-ANT2414A on each side of the camera
Good idea, but if your going to enhance the P2V side it might actually be better to follow spazmodic1 advice and install and amplifier and switch to matching good circ pol (cloverleaf) style antennas on both sides (camera & repeater). Doing this would probably provide best all around results. Good stuff.
Avidphoto said:
That is part of the Phantom 2 Vision package. It will not work on the Phantom 2 / Gopro version. But at least you can get a good gimble for a reasonable price...
Got my p2v up to 800 meters tonight also got about 1.5km of distance before the wifi cut out but I had full Rc again.
Flytrex will be needed for distances over 1km as the distance will read 'N/A' in the app after that point.
Flytrex will be needed for distances over 1km as the distance will read 'N/A' in the app after that point.
Has anyone tried connecting a the RX side of circular polarized antenna (cloverleaf or other) to the camera. Thanks to the recent photos, its seems like the install would be identical to what's simply being done at the repeater?
How about on the 5.8 RC side. I've seen several posts with a cloverleaf used on the RC. Anyone consider attaching the RX side of the antenna to the P2V. The antenna is easily assessable on the legs, no?
It's seems that a few antenna/radio guys here think that paired circular polarized antennas may provide the best "portable" solutions to the range issue.
How about on the 5.8 RC side. I've seen several posts with a cloverleaf used on the RC. Anyone consider attaching the RX side of the antenna to the P2V. The antenna is easily assessable on the legs, no?
It's seems that a few antenna/radio guys here think that paired circular polarized antennas may provide the best "portable" solutions to the range issue.
From all the posts I've seen thus far, I've come to the conclusion that both of the antennas on the Wifi repeater work in tandem, as opposed to the initial belief that one specifically speaks to the phantom and the other your phone or tablet. So using two antennas together would provide the best possible overall performance as it will provide a larger view of the sky. Though one antenna has seemed sufficient for most of you, although since both antennas are working I'd suggest having both your updated antenna as well as the remaining connect built in antenna both pointed towards your Phantom to give the best view of the sky even though at greater range the smaller antenna will no longer be coming in to play here.
BenDronePilot said:
You are correct. The 2 antennas in the repeater act as a diversity system - the repeater picks the antenna with the best signal. The local signal is always going to be strong, so not a problem. Using 2 directional antennas, replacing both internal ones - separated as much as possible -- would be the best result, if perhaps cumbersome. It's all about picking the best compromise!
Personally I choose medium gain (9dBi ish) omni antennas and a higher powered repeater as that gets good range without pointing issues, and saves modifying the PVs supplied repeater. But it's all about personal choice!
Hi all, actually got to do my first flight today after all the bad weather in the uk. Have done a lot of reading on range and antennas while waiting to fly!
I found that having the stock repeater at top of charge for each flight appeared to make a difference. So much so that I managed nearly 500 Metres with vision still working. Still being new to this model and set up I fumbled for a screen capture and lost the signal but did capture it at 452 Metres. I have ordered a 1500mW repeater from China with 3 omni pole antennas. I plan to replace 2 of these omnis with 14 DBI directional antennas with a 30 degree beam each and leave the single omni to to the near range work. If my very rough path link calculations are correct and depending on the local noise I would expect to see a range approaching 3 km or st least the range of the stock transmitter.
I found that having the stock repeater at top of charge for each flight appeared to make a difference. So much so that I managed nearly 500 Metres with vision still working. Still being new to this model and set up I fumbled for a screen capture and lost the signal but did capture it at 452 Metres. I have ordered a 1500mW repeater from China with 3 omni pole antennas. I plan to replace 2 of these omnis with 14 DBI directional antennas with a 30 degree beam each and leave the single omni to to the near range work. If my very rough path link calculations are correct and depending on the local noise I would expect to see a range approaching 3 km or st least the range of the stock transmitter.
Attachments
gpauk said:
Last time I installed TP-Link's 9dbi on mine, I didn't seem to get any gain when it was plugged to the right-side one. After switching it to the left port, I could move 20-30% further away. But then again I wasn't in the countryside at the time, so it could be due to interference or whatnot...
DON'T UPGRADE TO THE LATEST 1.0.31 App UPDATE. The spacing is all messed up and it's crashing my iPhone 5s.
Others are reporting the same thing. Turn off your auto-update on your iPhone and iPads etc to prevent the update.
Others are reporting the same thing. Turn off your auto-update on your iPhone and iPads etc to prevent the update.
I suspect that the extra range being seen on the transmitter control signal when a largish tplink antenna is placed directly in front of it is due to a passive repeater being inadvertently set up. I.e. the omni antenna induces the transmission signal into the directional antenna. The directional antenna then transmits on the 5.8Ghz signal in a more focused beam hence creating more range. The spec of the tplink antennas could certainly handle 5.8Ghz as well as 2.4Ghz at the same time.
In the same way this might be a solution for the camera end. Place a patch panel on the outside of the camera case directly in line with the internal patch antenna. Then hard wire this to a larger directional panel. Repeat on both sides or place one on the rear of the PV? Saves taking the camera apart which looks quite delicate.
Any thoughts on this theory ? Can anyone do the calculations on this ?
In the same way this might be a solution for the camera end. Place a patch panel on the outside of the camera case directly in line with the internal patch antenna. Then hard wire this to a larger directional panel. Repeat on both sides or place one on the rear of the PV? Saves taking the camera apart which looks quite delicate.
Any thoughts on this theory ? Can anyone do the calculations on this ?
