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Old Dec 23, 2012, 02:01 PM
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I need some assistance fixing a video issue. I've attached a copy of my wiring diagram which I use for my DOSD and Dragonlink UHF on my 1.3ghz video. I had setup my plane as per this diagram and everything was working fine. I had great picture quality.
Then, I found out about CAT6 cable and so I unhooked the unit and decided to use CAT6 cable from the camera to the video Tx AND from the video Tx to my dragon OSD board. The only wire that is not going through the CAT6 is the yellow (video) cable from the camera to the DOSD board. Also, I connected the shield to ground only at the VTx end. Furthermore, although the diagram shows audio, I have not connected any audio wires.
Here's my problem: Ever since I made this change, I am getting a blurry video quality on my display. I can see everything, but the quality is reduced. It's the same type of difference a person would notice when they are getting bad vision.... the ability to see everything but it's blurry. As well, the color quality has been ruined. Instead of showing the proper colors.... the picture quality has more of a black/white quality to it. I wanted to isolate the issue and ensure it had something to do with my wiring, so I tried another VTx and then I tried a second camera, both acting as controlled variables. The video quality remained blurry.
At this point I have no clue why I'm not getting the video quality I had just before I upgraded to CAT6.

Any help would be appreciated.

Many Thanks
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Old Dec 23, 2012, 07:53 PM
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Another question for yall to ponder on: I have a new problem that just showed up with my video after having hooked up the nova OSD.

I just hooked up my Nova osd to my 5.8 tx/rx and I am running it on the sony 1/3 ccd camera from HK. now it seems very sensitive to light, and gets a thick black line on the screen when pointed at light. It happened before when i flew into the sun, and now it seems exaggerated when hooked up to the osd with a 3s. power is coming from a single source (2200mah 3s) has anyone had a similar problem? bad camera?
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Old Dec 23, 2012, 09:44 PM
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^That is a video impedance problem. If you are using Lawmate, that is your problem. If not, it is reither the wiring or the OSD.

-Alex
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Old Dec 23, 2012, 09:58 PM
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Originally Posted by IBCrazy View Post
^That is a video impedance problem. If you are using Lawmate, that is your problem. If not, it is reither the wiring or the OSD.

-Alex
No Lawmate - and no problem with the antenna's - using your bluebeams. with a clear picture (in low light) i took a flash light, shined it in the direction of the video, and I get the thick black line on the image again. So it is not loose connections, and the wiring was followed verbatium per BMSWEB's video tutorial.

It is the same problem as this video:
1/3 SONY CCD cam issue with sun (0 min 40 sec)


It just seems the OSD made things worse...
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Old Dec 24, 2012, 10:12 AM
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Originally Posted by williamjames View Post
I need some assistance fixing a video issue. I've attached a copy of my wiring diagram which I use for my DOSD and Dragonlink UHF on my 1.3ghz video. I had setup my plane as per this diagram and everything was working fine. I had great picture quality.
Then, I found out about CAT6 cable and so I unhooked the unit and decided to use CAT6 cable from the camera to the video Tx AND from the video Tx to my dragon OSD board. The only wire that is not going through the CAT6 is the yellow (video) cable from the camera to the DOSD board. Also, I connected the shield to ground only at the VTx end. Furthermore, although the diagram shows audio, I have not connected any audio wires.
Here's my problem: Ever since I made this change, I am getting a blurry video quality on my display. I can see everything, but the quality is reduced. It's the same type of difference a person would notice when they are getting bad vision.... the ability to see everything but it's blurry. As well, the color quality has been ruined. Instead of showing the proper colors.... the picture quality has more of a black/white quality to it. I wanted to isolate the issue and ensure it had something to do with my wiring, so I tried another VTx and then I tried a second camera, both acting as controlled variables. The video quality remained blurry.
At this point I have no clue why I'm not getting the video quality I had just before I upgraded to CAT6.

Any help would be appreciated.

Many Thanks
Hi William sounds as though you are running into some of the same problems i did a little while back. Mine wasen't a video issue but a gps issue. I made some changes in hopes of improving rth video. I had changed my vtx antenna in hopes of making improvements. Turns out i went from one small problem to creating a larger one. After changing antenna i ending not being able to get a GPS lock at all due to my changes. Ended up putting everything back like it was. As the old saying goes if it is not broke don't fix it.lol
I wish i had a better solution for you but i am not qualified to give a tech. answer.
But i would consider changing back to how it worked before.
So many little things that you can do to improve or at times mess up a FPV system.
Hope you and your family have a Merry Christmas and Blessed New Year
Michael
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Old Dec 24, 2012, 02:07 PM
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Hi William sounds as though you are running into some of the same problems i did a little while back. Mine wasen't a video issue but a gps issue. I made some changes in hopes of improving rth video. I had changed my vtx antenna in hopes of making improvements. Turns out i went from one small problem to creating a larger one. After changing antenna i ending not being able to get a GPS lock at all due to my changes. Ended up putting everything back like it was. As the old saying goes if it is not broke don't fix it.lol
I wish i had a better solution for you but i am not qualified to give a tech. answer.
But i would consider changing back to how it worked before.
So many little things that you can do to improve or at times mess up a FPV system.
Hope you and your family have a Merry Christmas and Blessed New Year
Michael
Hi Michael,
Thank you kindly for sharing your experience. You're absolutely right, I should of never fixed something that wasn't broke. Since I made that post, I was able to resolve the issue. Basically, I went from the Cat6 cable back to regular cable and the picture quality was still really blurry and still displaying as black/while when the camera was clearly a color camera. At this point, I'm thinking that it must be the DOSD board. But then it occurred to me that maybe I should start from the bare minimums and add items onto the wiring and that way I will not only have isolated the issue but also (hopefully) find out exactly what was causing the bad video. So I pulled out an extra set of connectors for my camera and VTx. I started by just doing a direct connection, no toroids, no filters etc.... I powered the unit and the picture quality was perfect. I then added a LC filter and still no problems. By now I know for sure that my DOSD is not the problem (thank God! ). Next, I added a toroid to the video wire coming out of the Vtx and another on the cam video wire. Powered up my unit and BINGO!!... that was my problem. I was getting the same bad picture. I removed 1 video toroid and it made a big improvement... removed the second one and my picture quality was perfect yet again. I put everything back together minus the toroids on the video cables and everything was good to go. I hope this helps someone else out there who finds themselves in a similar situation.

Many thanks for the warm wishes. I wish you and your respective family a very Merry Christmas and a Happy New Year
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Old Dec 24, 2012, 02:53 PM
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Nice to hear William,

A little explanation from my side. You roughly have two groups of wires: supply wires and signal wires. Supply wires have fixed voltages (DC). Interference normally comes from the inside (from another device on the same line). To minimize it you add low-pass filters like toroid/coil/capacitor that block high frequencies. Signal wires carry AC current (possibly on top of a DC-voltage) that can be of any frequency. Interference normally comes from the outside, e.g. cross-talk of neighbouring wires. This can be solved by cancelling out the interfering signal by twisting the wires and keeping them away from other wires. Using a toroid here can be harmful like you already know from experience.

Martin
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Old Dec 24, 2012, 03:20 PM
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Nice to hear William,

A little explanation from my side. You roughly have two groups of wires: supply wires and signal wires. Supply wires have fixed voltages (DC). Interference normally comes from the inside (from another device on the same line). To minimize it you add low-pass filters like toroid/coil/capacitor that block high frequencies. Signal wires carry AC current (possibly on top of a DC-voltage) that can be of any frequency. Interference normally comes from the outside, e.g. cross-talk of neighbouring wires. This can be solved by cancelling out the interfering signal by twisting the wires and keeping them away from other wires. Using a toroid here can be harmful like you already know from experience.

Martin
Hi Martin,

Thanks so much for that info. For me, working with electricity is still relatively new so everything you mentioned was very helpful. Actually, your posts have always been helpful - Thank you
You mentioned to twist wires. In this case, I have 2 video wires that go in individually through single pin connectors. So there is nothing I can twist the video wire around (no other wires running beside it). What other suggestion do you have to minimize the noise that comes from my stand alone video wires which are coming from my VTx and Cam (both going into the DOSD)?

Thanks again
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Old Dec 24, 2012, 03:29 PM
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Hi Michael,
Thank you kindly for sharing your experience. You're absolutely right, I should of never fixed something that wasn't broke. Since I made that post, I was able to resolve the issue. Basically, I went from the Cat6 cable back to regular cable and the picture quality was still really blurry and still displaying as black/while when the camera was clearly a color camera. At this point, I'm thinking that it must be the DOSD board. But then it occurred to me that maybe I should start from the bare minimums and add items onto the wiring and that way I will not only have isolated the issue but also (hopefully) find out exactly what was causing the bad video. So I pulled out an extra set of connectors for my camera and VTx. I started by just doing a direct connection, no toroids, no filters etc.... I powered the unit and the picture quality was perfect. I then added a LC filter and still no problems. By now I know for sure that my DOSD is not the problem (thank God! ). Next, I added a toroid to the video wire coming out of the Vtx and another on the cam video wire. Powered up my unit and BINGO!!... that was my problem. I was getting the same bad picture. I removed 1 video toroid and it made a big improvement... removed the second one and my picture quality was perfect yet again. I put everything back together minus the toroids on the video cables and everything was good to go. I hope this helps someone else out there who finds themselves in a similar situation.

Many thanks for the warm wishes. I wish you and your respective family a very Merry Christmas and a Happy New Year
Certainly glad to hear you got your problem fixed.

And thanks Martin for explination of how it works.
Michael
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Old Dec 24, 2012, 06:16 PM
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Originally Posted by williamjames View Post
...
You mentioned to twist wires. In this case, I have 2 video wires that go in individually through single pin connectors. So there is nothing I can twist the video wire around (no other wires running beside it). What other suggestion do you have to minimize the noise that comes from my stand alone video wires which are coming from my VTx and Cam (both going into the DOSD)?

Thanks again
Ok, that picture explains it, thanks.

In my opinion you should not run single wires like that. It would be better to pair your signal wires each with a ground wire and then twist them. Ideally, noise will then be picked up equally by the signal- as well as ground-wire so their voltage difference caused by it will be non-existent. So noise from outside will be cancelled out properly.

But beware of ground loops. You better make a "star"-configuration e.g. with your OSD in the centre.
Hope this helps. Was there a problem anyway, I mean without the toroids?

Martin
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Old Dec 24, 2012, 06:43 PM
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Certainly glad to hear you got your problem fixed.

And thanks Martin for explination of how it works.
Michael
Cheers mate
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Old Dec 24, 2012, 06:51 PM
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Ok, that picture explains it, thanks.

In my opinion you should not run single wires like that. It would be better to pair your signal wires each with a ground wire and then twist them. Ideally, noise will then be picked up equally by the signal- as well as ground-wire so their voltage difference caused by it will be non-existent. So noise from outside will be cancelled out properly.

But beware of ground loops. You better make a "star"-configuration e.g. with your OSD in the centre.
Hope this helps. Was there a problem anyway, I mean without the toroids?

Martin
That sounds good. Just a couple of quick questions regarding your proposed wiring.

a) Based on the diagram that I have, I can twist the ground wire and yellow wire coming from the Tx together right?

b) The video wire that is coming from the camera to the DOSD is running alone. I don't have a ground wire running beside it... what would you recommend that I do for this?

Also, you had asked about toroids. Before I put the toroids/ LC Filter on, I was getting a lot of noise when I would throttle up the motor. It was really bad. But after I put the toroids on, that problem ceased to exist.

Thanks again
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Old Dec 24, 2012, 06:59 PM
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Originally Posted by guaglione87 View Post
No Lawmate - and no problem with the antenna's - using your bluebeams. with a clear picture (in low light) i took a flash light, shined it in the direction of the video, and I get the thick black line on the image again. So it is not loose connections, and the wiring was followed verbatium per BMSWEB's video tutorial.

It is the same problem as this video:
http://www.youtube.com/watch?v=2dAt3U0aCpc

It just seems the OSD made things worse...
I see now. This is a case of a saturated sensor in the camera (at least in the video). If the camera has changeable settings, then adjust the contrast and brightness. Also reducxing the sharpmness might help. Other than that, I don't know if there is a solution other than a different camera or a higher F number lens.

-Alex
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Old Dec 24, 2012, 07:20 PM
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Quote:
Originally Posted by williamjames View Post
That sounds good. Just a couple of quick questions regarding your proposed wiring.

a) Based on the diagram that I have, I can twist the ground wire and yellow wire coming from the Tx together right?

Right!

b) The video wire that is coming from the camera to the DOSD is running alone. I don't have a ground wire running beside it... what would you recommend that I do for this?

Or you can add a new ground wire (and remove gnd between cam and vtx), or you can shield the wire, or you can keep it away from noise sources.

Also, you had asked about toroids. Before I put the toroids/ LC Filter on, I was getting a lot of noise when I would throttle up the motor. It was really bad. But after I put the toroids on, that problem ceased to exist.

I guess you were too greedy on your toroids. Don't use them on signal wires unless you know what you're doing.

Thanks again
Good luck, I'm sure you'll succeed.
Martin
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Old Dec 24, 2012, 07:43 PM
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Good luck, I'm sure you'll succeed.
Martin
Many Thanks Martin... your help is much appreciated.
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