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Old Feb 24, 2011, 08:45 AM
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Quote:
Originally Posted by Andy W View Post
Alex,
is there a page or site giving more information on orientation/radiation pattern for the V antenna? I picked one up from ReadyMade, as well as a standard patch. They suggest the nose of the aircraft but don't specify horizontal or vertical.
For some reason I would have expected "point down" like traditional wire landing gear on a slow stick.
Thx!
..a
It must be vertical. I typically put the white element up and black element down.

-Alex
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Old Feb 24, 2011, 08:48 AM
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Originally Posted by StephenG View Post
Well you all have pushed me over the edge

I have been a spectator for years contemplating getting back into RC. Then a few months ago I stumbled across an FPV video on Youtube. I'm hooked!

I have an Easy Star on the way and an Arducopter under construction on the workbench. It will be a while before I actually fly FPV but I am allready tinkering with design ideas. I have run into one question that I have not been able to find a good answer to:

I would like to have two fixed cameras in my bird. One looking forward for FPV and one in the belly for a straight down shot. I am having trouble finding a good solution for a two channel video system. I am a licensed HAM so I am open to solutions that require ham license.

Suggestions??

Thanks Everyone for the wealth of info you have made available on this forum!

Stephen
Stephen,

Why not use a 900MHz and a 1.3GHz downlink? Use one frequency for each camera. I would recommend flying 72MHz and keeping your antenna as straight as possible. You won't be flying too far away with a helicopter, so 200-300mW will be plenty of RF power and shouldn't be too detrimental to your RC control.

-Alex
KJ4RIV
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Old Feb 24, 2011, 01:15 PM
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Does anyone know of some cheap (probably digital) servos that won't jitter when using 1.3ghz video link, prefferably to buy them at hobbyking? Or there problems with jittering at close to 1.3ghz for cheap servos like hxt900?
Also I plan to first fly with the stock permax 400 motors on my twinstar, do they produce alot of interference, is there anyway of overcoming that?
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Old Feb 25, 2011, 08:01 AM
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Quote:
Originally Posted by IBCrazy View Post
Stephen,

Why not use a 900MHz and a 1.3GHz downlink? Use one frequency for each camera. I would recommend flying 72MHz and keeping your antenna as straight as possible. You won't be flying too far away with a helicopter, so 200-300mW will be plenty of RF power and shouldn't be too detrimental to your RC control.

-Alex
KJ4RIV
Alex,

Thanks for the reply. Using two seperate video TX on two different bands will certainly work. I was hoping for a solution that may save a bit on weight & battery load.

As to the control frequency, can you tell me why you recommend 72mhz over 2.4ghz? I haven't looked that closely at radio specs but I assumed that the ability to run a full half wave on the rx and an easily available gain antenna on the tx would favor 2.4ghz.

Given that I will be flying the EZ Star as well as the Quad (both FPV) I woud like to have reliable range exceeding 1 mile. I live in a VERY rural area and am surrounded by thousands of acres of farmland & wilderness waiting to be explored

Thanks again.


Stephen

KB7KJY
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Old Feb 25, 2011, 08:10 AM
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I too am interested in that. I am also interested to know ideal antenna placement for the RC Rx's antenna relative to the video Tx antenna, both 2.4GHz and 72MHz (R/C).
..a
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Old Feb 25, 2011, 08:42 AM
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There are several reasons for going with 72 MHz, but the main reason is failsafes. With all the RF interference onboard your plane/helicopter, you are going to get weak signals. When the signal gets weak, do you want it to glitch or lock you out? A 2.4GHz control system will lock out and crash.

Second, the low frequency of 72MHz is very far out of the video bands we use. 2.4GHz band is swamped with devices. Thus interference is less of an issue on 72MHz.

-Alex
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Old Feb 26, 2011, 09:36 PM
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^What IBCrazy said.

I live in a very noisy RF environment but 72Mhz is no problem. 1.3Ghz looks clean too, but 900mhz not so much hehe I guess they are still using those dirty old cell towers around.
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Old Feb 27, 2011, 04:03 PM
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Imagine
Your FPV Camera stops working during flight (Simply as it uses its own battery and the battery runs out of energy - It could be GoPro or a photo camera or what ever). If you have no return to home - than you are done.
My micro copter OSD continues to send data even though the video source is dead. If you have artificial horriont, home arrow and all other usual display working on a black screen - than you can easily bring your blind plane back using only the telemetry. Why don't the OSD Producers do this for us.
Eagle tree OSD Pro does not have this feature.
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Old Feb 28, 2011, 12:13 AM
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Had a really close call today. Had the Easy Star out in some windy conditions. I was out about 1800 feet east into the wind. Video started cracking up and I couldn't read the data on the screen. In a last ditch effort I removed my goggles and cranked up the throttle so I could hear it. I was Amazed that the plane was about 3500 feet to my north west. That was fast. I turned the antenna and put the goggles back on and, luckily, I got video back and brought it home safely. I was actually shaky! my plane has about $600 worth of equipment on it. I will order a tracker tomorrow.

However, I was amazed that my entire system functioned at 3500 feet.

Here is my config:

Multiplex Easy Star (Raven Rq-11 on the way)
stryker motor with castle 36 ESC
eagle tree OSD with data logger and GPS module
900mhz 800mw TX with VEE from readymade
ar7000 perp config
dx6i
tri pod mount rcvr with patch antenna.

Im such a noob.


P.S. on a side note, Flying a tri-copter in FPV is REALLY HARD!
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Old Feb 28, 2011, 01:13 PM
Why is the Rum gone?
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lol

Quote:
Originally Posted by traderdmb View Post

However, I was amazed that my entire system functioned at 3500 feet.

Here is my config:

Multiplex Easy Star (Raven Rq-11 on the way)
stryker motor with castle 36 ESC
eagle tree OSD with data logger and GPS module
900mhz 800mw TX with VEE from readymade
ar7000 perp config
dx6i
tri pod mount rcvr with patch antenna.

Im such a noob.


P.S. on a side note, Flying a tri-copter in FPV is REALLY HARD!

I've seen people fly fpv witht heir dx6i's and lockout in person. It doesn't take much to lose reception.
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Old Feb 28, 2011, 07:56 PM
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Quote:
Originally Posted by sim_io View Post
I've seen people fly fpv witht heir dx6i's and lockout in person. It doesn't take much to lose reception.

yup just happened to me the other day with my dx8!
I am waiting on a u.fl to sma pigtail to finish my 1watt boosted dx6i but i was to impatiant to fly with my new set up and I paid for it my reciver locked out at 3/10ths of a mile away it was fine flying up high but i decided to come a little lower and BAM LOCKOUT my video how ever was rock solid until the plane was 10ft or so from the ground.

So now I am going to wait till my dx6i is finished and I get an osd with RTH before I have any more FPV flights

easy star FPV crash video Blackout " why you don't use spectrum for FPV" (11 min 41 sec)
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Old Feb 28, 2011, 10:30 PM
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Quote:
Originally Posted by hotdog1 View Post
yup just happened to me the other day with my dx8!
I am waiting on a u.fl to sma pigtail to finish my 1watt boosted dx6i but i was to impatiant to fly with my new set up and I paid for it my reciver locked out at 3/10ths of a mile away it was fine flying up high but i decided to come a little lower and BAM LOCKOUT my video how ever was rock solid until the plane was 10ft or so from the ground.

So now I am going to wait till my dx6i is finished and I get an osd with RTH before I have any more FPV flights
Youre very lucky the EZ* didnt land on that busy road!! Could have been a whole lot worse.
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Old Feb 28, 2011, 10:33 PM
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I'm surprised by the number of ppl here using Spektrum 2.4ghz for FPV. Dont you guys read all the nasty posts about 2.4 lockouts and range issues ?????
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Old Feb 28, 2011, 10:39 PM
"Chuck Yeager"
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Bradenton FL
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Quote:
Originally Posted by lloydh View Post
I'm surprised by the number of ppl here using Spektrum 2.4ghz for FPV. Dont you guys read all the nasty posts about 2.4 lockouts and range issues ?????
Yes but i was also testing to see if my updated dx8 to the new Spectrum DSMX firmware would help this lockout issue with Spectrum 2.4 gear.... Guess not
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Old Mar 01, 2011, 06:10 AM
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Quote:
Originally Posted by lloydh View Post
I'm surprised by the number of ppl here using Spektrum 2.4ghz for FPV. Dont you guys read all the nasty posts about 2.4 lockouts and range issues ?????
The Spektrum full range RX with satellite reciever isn't terrible, but the rest are. It is kind of scary that some people use a park flyer Spectrum RX for FPV.

Remember, it's not the radio that gives the range, it's the reciever.

-Alex
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