Stock P2V 2.7 KM (8,850') Long Range Test

Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

RemE said:
Since you have so much experience, what do you expect the range is for the Docooler 1500mW repeater with 9db dipoles on it to be? Just looking for a educated guess.

For FPV video range, the repeater is mainly for RX. The range does NOT make too much difference for a 1500mW or 500mW repeater. The key factor is RX antenna attaching to the repeater, and the TX power and antenna of P2V camera.

Imagine, when you hook up a 14 dB panel antenna to stock repeater (50 mW per DJI claimed), you may get 800-1,000M range. When you use the same antenna on 1,500 mW repeater, you probably don't have too much gain in range considering 30X more power.

If you further look into detailed spec. of ARG-1211 (AKA Docooler), the TX power of 802.11n is 25 dBm (~320mW, not 1500mW) as I recalled. I believe P2V is using 802.11n though no official spec. from DJI.

It is hard to estimate 2.4G FPV range since environment (mainly RF noise floor) affect the range most. If you stand nearby a high power RF noise source, you probably would not reach 100 meters range.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
RemE said:
Since you have so much experience, what do you expect the range is for the Docooler 1500mW repeater with 9db dipoles on it to be? Just looking for a educated guess.

For FPV video range, the repeater is mainly for RX. The range does NOT make too much difference for a 1500mW or 500mW repeater. The key factor is RX antenna attaching to the repeater, and the TX power and antenna of P2V camera.

Imagine, when you hook up a 14 dB panel antenna to stock repeater (50 mW per DJI claimed), you may get 800-1,000M range. When you use the same antenna on 1,500 mW repeater, you probably don't have too much gain in range considering 30X more power.

If you further look into detailed spec. of ARG-1211 (AKA Docooler), the TX power of 802.11n is 25 dBw (~350mW, not 1500mW) as I recalled. I believe P2V is using 802.11n though no official spec. from DJI.

It is hard to estimate 2.4G FPV range since environment (mainly RF noise floor) affect the range most. If you stand nearby a high power RF noise source, you probably would not reach 100 meters range.

That's not quite correct. The range is related to the link budget in both directions. A higher powered repeater should have a much more sensitive rx stage as well as a tx pa stage (otherwise it won't work well..). Add that to the an improved antenna (the stock antennas with a high power repeater tend to be better than the standard PV ones) and you get a considerable improvement.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

gpauk said:
PVFlyer said:
RemE said:
Since you have so much experience, what do you expect the range is for the Docooler 1500mW repeater with 9db dipoles on it to be? Just looking for a educated guess.

For FPV video range, the repeater is mainly for RX. The range does NOT make too much difference for a 1500mW or 500mW repeater. The key factor is RX antenna attaching to the repeater, and the TX power and antenna of P2V camera.

Imagine, when you hook up a 14 dB panel antenna to stock repeater (50 mW per DJI claimed), you may get 800-1,000M range. When you use the same antenna on 1,500 mW repeater, you probably don't have too much gain in range considering 30X more power.

If you further look into detailed spec. of ARG-1211 (AKA Docooler), the TX power of 802.11n is 25 dBw (~350mW, not 1500mW) as I recalled. I believe P2V is using 802.11n though no official spec. from DJI.

It is hard to estimate 2.4G FPV range since environment (mainly RF noise floor) affect the range most. If you stand nearby a high power RF noise source, you probably would not reach 100 meters range.

That's not quite correct. The range is related to the link budget in both directions. A higher powered repeater should have a much more sensitive rx stage as well as a tx pa stage (otherwise it won't work well..). Add that to the an improved antenna (the stock antennas with a high power repeater tend to be better than the standard PV ones) and you get a considerable improvement.

Higher TX power repeater does NOT always imply better RX sensitivity. This is easy to clarify from manufactory spec of other repeaters, though there is no detail spec of stock repeater from DJI.

If you look at the spec of ARG-1211 (TX 1,500 mW) RX sensitivity of MCS15 is -73 dBm per http://www.argtek.com/style/frame/templ ... et=color_1.

Rocket M2 (TX 640 mW) RX sensitivity of MCS15 is -75 dBm per the datasheet.

Based on the above spec of 2 devices, Rocket M2 has better RX sensitivity than ARG-1211, even ARG-1211 has higher TX power. No offence, just want to clarify the facts.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

RemE said:
themosttoys said:
Correct. BTW, you are losing the same 3dbi by using the linear wifi antenna. The P2V camera uses circular polarized antenna.

Sent from my Note 3 using Tapatalk 4

??? I thought the stock Vision's video WiFi patch antennas were linear???

So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:
 

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Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

themosttoys said:
RemE said:
themosttoys said:
Correct. BTW, you are losing the same 3dbi by using the linear wifi antenna. The P2V camera uses circular polarized antenna.

Sent from my Note 3 using Tapatalk 4

??? I thought the stock Vision's video WiFi patch antennas were linear???

So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:

Thanks themosttoys for sharing this crystal clear picture of the camera antenna. This is a single feed truncated corner microstrip patch of LHCP. Since most of commercial/hobby helical antennas are RHCP, thus I have to build LHCP helical myself to match P2V camera.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:
[/quote]

Just regarding the camera antenna. I changed one side to 5dbi omni and I didn't see better result or may be worst. I have connect it into the right place in front of the camera. Just wonder what result have you got if you got the same mod. I think my final step is using 2000mw amplifier with 9dbi tp link directional to accomplish 1mile with steady Video.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

leekawey said:
Just regarding the camera antenna. I changed one side to 5dbi omni and I didn't see better result or may be worst. I have connect it into the right place in front of the camera. Just wonder what result have you got if you got the same mod. I think my final step is using 2000mw amplifier with 9dbi tp link directional to accomplish 1mile with steady Video.

Using a 5dbi omni on the P2V and a 9dbi omni on the stock repeater I have over 4000 feet of solid video (at 640x480) with full pan (yaw). I've not had a chance to test maximum range yet. I have 800mw amp for P2V, just have not had a chance to test. Lots to test, just been too busy.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
gpauk said:
That's not quite correct. The range is related to the link budget in both directions. A higher powered repeater should have a much more sensitive rx stage as well as a tx pa stage (otherwise it won't work well..). Add that to the an improved antenna (the stock antennas with a high power repeater tend to be better than the standard PV ones) and you get a considerable improvement.

Higher TX power repeater does NOT always imply better RX sensitivity. This is easy to clarify from manufactory spec of other repeaters, though there is no detail spec of stock repeater from DJI.

If you look at the spec of ARG-1211 (TX 1,500 mW) RX sensitivity of MCS15 is -73 dBm per http://www.argtek.com/style/frame/templ ... et=color_1.

Rocket M2 (TX 640 mW) RX sensitivity of MCS15 is -75 dBm per the datasheet.

Based on the above spec of 2 devices, Rocket M2 has better RX sensitivity than ARG-1211, even ARG-1211 has higher TX power. No offence, just want to clarify the facts.

Yep -- that's why I said "should"... A high power repeater with no improvement on rx performance is.. not a lot of use as a rule, as there's normally data traffic both ways.... :)
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

leekawey said:
So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:

Just regarding the camera antenna. I changed one side to 5dbi omni and I didn't see better result or may be worst. I have connect it into the right place in front of the camera. Just wonder what result have you got if you got the same mod. I think my final step is using 2000mw amplifier with 9dbi tp link directional to accomplish 1mile with steady Video.[/quote]

It depends on how did you lay the 5 dBi Omni on P2V. The perfect layout is perpendicular to ground for range (not for altitude), but it may not fit the landing gear due to the length of omni. You may extend /raise the landing gear similar to this http://www.banggood.com/DJI-Phantom-Lan ... 11056.html.

However, using 5 dBi omni on P2V alone has no way to achieve your goal - 1 mile (1.6 KM) range. Upgrading antenna of repeater (maybe together with a quality booster) may extend your FPV range to >1 KM.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
themosttoys said:
So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:

Thanks themosttoys for sharing this crystal clear picture of the camera antenna. This is a single feed truncated corner microstrip patch of LHCP. Since most of commercial/hobby helical antennas are RHCP, thus I have to build LHCP helical myself to match P2V camera.

Interesting... Never looked into the camera -- or the stock repeater, so that's worth knowing - thanks for the photo!
It also shows that dji have used a pretty poor antenna -- fr4 type pcb patch antennas are fine for short range radio, far from ideal for FPV where range is an issue...
My setup gets me 2km + range -- or absolute rock stable VFR range pretty much regardless of terrain, which was my goal..
But - rats. I'll have to mod the camera now I know what's in there!!
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

gpauk said:
PVFlyer said:
themosttoys said:
So did I until two days ago when PVFlyer pointed it out to me (I had never bothered to look closely.) Here is a picture of the patch, it is clearly a circular polarized square patch microstrip:

Thanks themosttoys for sharing this crystal clear picture of the camera antenna. This is a single feed truncated corner microstrip patch of LHCP. Since most of commercial/hobby helical antennas are RHCP, thus I have to build LHCP helical myself to match P2V camera.

Interesting... Never looked into the camera -- or the stock repeater, so that's worth knowing - thanks for the photo!
It also shows that dji have used a pretty poor antenna -- fr4 type pcb patch antennas are fine for short range radio, far from ideal for FPV where range is an issue...
My setup gets me 2km + range -- or absolute rock stable VFR range pretty much regardless of terrain, which was my goal..
But - rats. I'll have to mod the camera now I know what's in there!!

I think DJI had done a pretty good job in design of camera/antenna, and it covers 300 meters range with solid video. Such range is good enough for most of photographers and casual FPV & RTF flyers. The antenna does not have high gain due to compact size, which is inevitable. A beauty of low gain antenna is 360 degree sphere-like RF pattern coverage.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
gpauk said:
PVFlyer said:
Thanks themosttoys for sharing this crystal clear picture of the camera antenna. This is a single feed truncated corner microstrip patch of LHCP. Since most of commercial/hobby helical antennas are RHCP, thus I have to build LHCP helical myself to match P2V camera.

Interesting... Never looked into the camera -- or the stock repeater, so that's worth knowing - thanks for the photo!
It also shows that dji have used a pretty poor antenna -- fr4 type pcb patch antennas are fine for short range radio, far from ideal for FPV where range is an issue...
My setup gets me 2km + range -- or absolute rock stable VFR range pretty much regardless of terrain, which was my goal..
But - rats. I'll have to mod the camera now I know what's in there!!

I think DJI had done a pretty good job in design of camera/antenna, and it covers 300 meters range with solid video. Such range is good enough for most of photographers and casual FPV & RTF flyers. The antenna does not have high gain due to compact size, which is inevitable. A beauty of low gain antenna is 360 degree sphere-like RF pattern coverage.

Yes, I agree, it does a good job and meets it's spec -- my comments are in the context of the massive range improvements we're all trying to make. :D
On the other hand, decent substrate patches for the 2.4GHz band are very cheap and rather better then pcb based ones...
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

I made a cross-frame by cardboard for my homebrew helical. I will need to add a wavetrap for matching 50 ohm impedance. I will further need a SWR meter to measure and fine tune the value. Hope to get all this done in next 2 weeks. Keep my fingers crossed.
 

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Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

I did another range test. Vision App showed CONTROL SIGNAL LOST of 5.8G transmitter at 2.27 KM and triggered RTH, video downlink was still fine though.

Phantom 2 Vision 2.27 KM (7,500 Feet) Range Test http://youtu.be/9qaMw5knKWs
Video is stabilized by YouTube.
 

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Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

Great job.
Could you review step by step to made it ? :)
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

sangfhas said:
Great job.
Could you review step by step to made it ? :)

I basically DIY a pair of LHCP helical antenna as mentioned in earlier posts, which is a key step for long range. The LHCP helical matches P2V camera antenna, but most of commercial / hobby helicals available in the market are RHCP. Instead of DIY, you may consider LHCP patch panel antenna, like this http://www.l-com.com/wireless-antenna-2 ... -connector.
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
sangfhas said:
Great job.
Could you review step by step to made it ? :)

I basically DIY a pair of LHCP helical antenna as mentioned in earlier posts, which is a key step for long range. The LHCP helical matches P2V camera antenna, but most of commercial / hobby helicals available in the market are RHCP. Instead of DIY, you may consider LHCP patch panel antenna, like this http://www.l-com.com/wireless-antenna-2 ... -connector.

Why don't you use RHCP helical antenna ?
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

PVFlyer said:
szobell said:
Thanks for sharing the video - that is some impressive range!! I'd love to see an image of your antenna setup - please post!

This is my ground station setup of LHCP helical antenna for 2.4G video, and 11 dBi patch panel for 5.8G transmitter.

PVFlyer

many thanks for your testing and posts. Is it possible to purchase 2 of those LHCP helicals?
 
Re: Phantom 2 Vision 1.7 KM (5,600 Feet) Long Range Test

LMC said:
PVFlyer said:
sangfhas said:
Great job.
Could you review step by step to made it ? :)

I basically DIY a pair of LHCP helical antenna as mentioned in earlier posts, which is a key step for long range. The LHCP helical matches P2V camera antenna, but most of commercial / hobby helicals available in the market are RHCP. Instead of DIY, you may consider LHCP patch panel antenna, like this http://www.l-com.com/wireless-antenna-2 ... -connector.

Why don't you use RHCP helical antenna ?

Simply because of P2V camera is LHCP, and I need to use LHCP helical to match it. If I use RHCP antenna, there is max -30 dB (1000X) signal lost. My Wifi video link would probably drop out less than 100 meters.

If I really need to go for RHCP helical, I need to change P2V camera antenna to RHCP matching the helical, such as cloverleaf CL or skew planar wheel SPW. This will further introduce another problems, such as:

1. Do I need 1 or 2 CLs or SPWs
2. Payload of 2 antennas
3. Where to install them
4. If I install only 1 on either left or right side, what happy if I yaw P2V left or right, then I may not have LOS to such antenna, thus video may drop out
5. If I install underneath lower the camera to ensure 360 degree yawning with LOS, the antenna is likely longer than landing gear, how can I land
6. If I extend the landing gear, what's the extra payload and how can it fit to my P2V case
... Etc.

So the simplest solution to me is LHCP helical.
 

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