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philthyy

full screen flicker?

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I finally flew my GWS Slow Stick with the CCD camera and 400mw transmitter with GP Patch antenna. It was such a rush, seeing my town from above! Image quality was excellent, but sometimes the entire screen would "flicker" bright white diagonal lines. What causes this? I'm running a 11.1 Li-Po for the camera and transmitter, and a seperate battery for the motor and electronics. Is this a problem with the voltage falling below 12v? I know Li-po's are a tad over 12v when fully charged, but fall below that under load. I haven't tried to rotate my patch antenna yet to see if that solves the issue, but I'm not sure if it is antenna related or voltage related. Any ideas? Suggestions?

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I always use 3s LiPos to power 12V systems. Works perfectly over the entire discharge curve.

Couldn't that be a bad contact / vibration issue?

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Most often, reports of short video "flashes" are multipath or other RF signal related issues. Post a link to some samples of the white flashes -- reviewing them might make it easier to determine what is going on. Also describe the environment you are operating in (any metal fabric fences, houses, buildings, cars, etc., in close proximity?).

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Well, I'm glad to hear that 3 Li-Po's are good for 12v systems. I am flying right off the deck in my backyard, over the city of Fenton, MI. There are houses everywhere(I live in a sub) and my backyard is surrounded by a 8 foot high wooden privacy fence. Not the best flying enviroment! LOL! I have been aiming the patch antenna upwards at about a 45 degree angle. Should I aim it straight up? I'll definately check my contacts and make sure that everything is tight. Does it matter if my transmitter antenna on the plane is right by the motor and other electronics? I'll need to lenghten the lead if I need to move it farther away. This is a 1.2 system I bought off of Tinywireless.com, advertised to have 1500 feet of range with a 400mw transmitter. This transmitter actually has four DIP switches to adjust which frequency it operates on. Seeing as this system with CCD camera only cost $90 I don't really know if it is actually putting out 400mw, as so many cheap manufactures are basically lying about output power. As I am very much a clueless(but trying hard to learn!) noobie, I appreciate the help. Thanks guys!

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Hi!

This is my first post and I want to greet everyone here. Have been reading a while and it's a great forum. I am a 23 year young hobby-researcher from germany who also likes rc-modells and modifications to it.

I have just about the same problem. I think it is an Vibration AND Motor-Intereference problem.

What would you recommend to decouple/remove this intereferenceproblems? I already added a small 1uF and 33nF to the powercables.

I run on single 3 cell Lipo for receiver, nav-lights, motor and camera.

I also experience very bad range. The camera I use is marked "208c 2.4Ghz" and was cheap 50 bucks including transmitter. The range is about 300ft in open field but advertised 3 times that. 300ft is way to less to fly by cam-view-only via headset.

Best Greets,

Marcus

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Hi fallenangel! I definately suggest you build a GP patch antenna. That should help with range considerably. Also, make sure you're getting the exact voltage required for the transmitter, as I seem to recall reading somewhere on this site that if the voltage drops even a little bit it can really affect range. Good luck!

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Hi!

Thank you for the suggestions. While reading I already recognized that I need a better antenna.

I also saw that the TX of my 208c Hongkongcam runs on the same 5V as the camera, the 8v (white) cable was clipped off at the plug!? So no wonder why I got that bad range.

Once I build the "improvements" to my cam/tx I will report the resuls if anyone likes to hear...

Best greetz,

Marcus

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I would like to hear your results. I've been flying with my system since I last posted with excellent results. The only change is that I now have the RX and patch antenna much farther away from the monitor and my controller transmitter. I noticed that whenever I got my Hitec Flash 5 controller too close to the patch antenna while flying, the image would get flashes and\or image distortion. I'm not sure of the range of my camera and transmitter because I'm not really brave enough to fly that far away yet. I've been quite high, so that the plane is just a speck, with perfect reception, so I think my range is probably approaching the range of my controller. I'm not even going to think about flying out of my sight and using FPV only to control the plane until I get the FMA Co-Pilot, though. And someday I hope to get the Artificial Horizon from Mr RC-Cam to go along with it. It's my dream to fly within a two mile radius of my house using FPV only, and I know I would need the Co-Pilot and MAHI to do it safely. Someday...

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Try this. Get a pole or some way to elevate your receiver and antenna. The higher the better. That way your controller antenna will never be in front of your video receiver antenna. Just get a longer RCA cable to run down the pole to your monitor. I used a piece of metal conduit with an "L" on top to strap my receiver onto. The end of the conduit that I stuck in the ground was slash cut to make it easier to work into the ground without having to be driven into it.

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What a great Forum this is! The comment concerning raising the Rec/Ant as high as possible to eliminate as much of the "Controller" RF from impinging upon the Video's Antenna calls this to mind.

My first R/C single channel xmitter (1957) was placed on the ground and had a vibrator power supply from the car battery. The antenna was long and was vertical (~ 9 ft tall at 1/4 wavelength) It was on 27. If I fired it up at home, I knocked out nearby TVs. I know I had at least the third harmonic signal blasting out there. So a spurulous signal I had. My buddy and I built that three-tubed rig.

When I got my first EK 4 chanel set I found I could test the xmitter in the house by walking up to about 4 to 8 ft from the TV set. There would be a variable pitched hum and all kinds of wiggly lines which varied as you moved the sticks. I even thought I could detect my battery condition (charge) by the range. Those TV's had a two wire (brown, side by side) connection to the antenna p on the roof - suseptable to picking up RF.

Here is a Rube Goldberg solution. Since our xmitter impound area is covered with screen wire ( metallic wire) no signal on the 72 MHz freq. will go thru' the screen wire.

So if you find the 25 to 30 foot tall "tower" on which you'd put your grd-based antenna is difficult to carry to your flying site, think about this.

* Build a 6 foot by 6 foot wooden ( 2" x 2") covered with screen wire. This will at least attenuate the "controler" signal so the video antenna recieves only from the plane. Test at home with a smaller screen wire section first.

I know that if you are flying on 72mHz and walk into a room covered with metal screen wire - you will rekit your plane (crash). Thanks for this Forum.

Edited by Exporter

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