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This thread is privately moderated by IBCrazy, who may elect to delete unwanted replies.
Dec 14, 2012, 06:25 PM
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Quote:
Originally Posted by IBCrazy View Post
^The sporatic jitters are because your transmitter is very close to your servos and the wires are not twisted. Twist up the wires and most of the jittering will be gone.

The other issue with the camera can be fixed by uncasing it and soldering directly to the board.

-Alex
This may sound like a dumb question but does it matter if the wires are braided INSTEAD of twisted??

Any one method do a better job at reducing noise?
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Dec 14, 2012, 07:09 PM
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QUAD4EVER's Avatar
Related question - would wrapping the wires in conductive copper foil tape yield the same benefits as twisting?
Dec 14, 2012, 07:28 PM
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JLT_GTI's Avatar
Quote:
Originally Posted by QUAD4EVER View Post
Related question - would wrapping the wires in conductive copper foil tape yield the same benefits as twisting?
no... as far as i understand any shielding should be conected to ground..

What i used to shield the main wires (camera, video TX and PPM) was audio shielded stereo wire.. and use the external shielding as ground




More info here (in spanish)
Dec 14, 2012, 07:48 PM
Registered User
Quote:
Originally Posted by JLT_GTI View Post
no... as far as i understand any shielding should be conected to ground..

What i used to shield the main wires (camera, video TX and PPM) was audio shielded stereo wire.. and use the external shielding as ground
You need to solder the shield to the ground wire on one side only... the side that is transmitting. Failure to do this may result in the noise in fact being amplified.
Dec 14, 2012, 10:22 PM
Engineer for Christ
IBCrazy's Avatar
You really need to do a little research on RFI and EFI. Once you get into it a little bit, you will understand certain techniques that minimize interference. However, some electronics are just sensitive to it and there is nothing you can do about it other than either switch to a lower VTX power, or replace the affected component. For 4-5km, 100mW is more than enough.

-Alex
Dec 15, 2012, 12:04 AM
Suspended Account
[QUOTE=JLT_GTI;23527686]Sorry to quote myself.. but i havent got much info on this..


Also i need sugestions for another problem..

Any hint or sugestion to how mount the camera wire? now i have it like this:




But im having problems.. the plug was well fixed with hot glue.. (so it doesnt move), but one of the wires broke inside due to the 180 pan movements.. its like i cant put the wire in a way where is not streesed when moved 90 to each side...[/QUOTE

Twist it so its like a curl
The wires from camera is straight wire but circular
This will show for travel without stress

Where wires come from camera add extra hot glue so they are not stressed

Make sure the camera does not turn to far around with stopper to prevent wires to get binded

Take off outer plastic from camera wires so they are more flexible

You can make wires move with camera and not bind this way
Last edited by David22; Dec 15, 2012 at 12:11 AM.
Dec 15, 2012, 12:17 AM
Suspended Account
Quote:
Originally Posted by IBCrazy View Post
^The sporatic jitters are because your transmitter is very close to your servos and the wires are not twisted. Twist up the wires and most of the jittering will be gone.

The other issue with the camera can be fixed by uncasing it and soldering directly to the board.

-Alex
If you use good servos the video tx and servo can be right on top of each other

It's best to choose best equipment the first time rather than need to separate stuff

Even with high powered video tx a servo works no problem when very close

Pick your components properly rather than have to separate them

This makes fpv much better
P

Once you find channel that works best hot glue that channel as well as connector to camera and video tx
No need for uncasing camera as hot glue makes for sold connection
Dec 15, 2012, 01:06 AM
Registered User
Hey guys, any of you know a good way to shield my tx from uhf so i can have my long range mounted on my transmitter... My tslrs gear sometimes caused problems or the a9 caused problems.... Any how u know what i mean. Ive sinced jumped ship and i have ezuhf enroute... Doing a chage over, had some issues on my smaller quads with interference and tslrs. Amazing system and worked great on my planes, any interest in it pm me. Ill have it the classifieds once i do the changeover
Dec 15, 2012, 02:59 AM
The way of being is doing.
IMEIV's Avatar
Quote:
Originally Posted by IBCrazy View Post
The reason for twisting is inductive coupling. A radiated field will couple with nearby wires inducing a current in them. Twisting the wires causes the induced currents to balance and thus they knock themselves right out. This is how CAT5 and CAT6 cable work.

-Alex
Alex.. twisting wires or putting a toroid have a result the same function ?
Dec 15, 2012, 08:54 AM
Wallop!
Martin7182's Avatar
Twisting will cancel out nearby EMI (of any frequency), a toroid just blocks high frequencies.

I would not use toroids for signal wires such as servos and video signals; these wires carry high frequency signals which you don't want to block. So use twisting here. Use toroids for dc-power wires like between battery and camera/vtx.

Martin
Dec 15, 2012, 08:57 AM
Registered User
JLT_GTI's Avatar
Quote:
Originally Posted by williamjames View Post
You need to solder the shield to the ground wire on one side only... the side that is transmitting. Failure to do this may result in the noise in fact being amplified.
But the shielding is the ground itself .... it needs to be conected to each side or there is no ground
Dec 15, 2012, 09:17 AM
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JLT_GTI's Avatar
Quote:
Originally Posted by Martin. View Post
Twisting will cancel out nearby EMI (of any frequency), a toroid just blocks high frequencies.

I would not use toroids for signal wires such as servos and video signals; these wires carry high frequency signals which you don't want to block. So use twisting here. Use toroids for dc-power wires like between battery and camera/vtx.

Martin
any guide on twisting? i just twist the wires as much as possible without the wires "notting" ..it seems to be quite easy and it remains twisted rather well.. that makes me think i might be doing something wrong
Dec 15, 2012, 09:41 AM
Wallop!
Martin7182's Avatar
I think the (different!) twist rate is only important when using multiple twisted pairs inside one cable. For a couple of different cables it should not matter that much; just use enough twisting so that EMI-exposure will be equal for both wires. And maybe even more important, use some separation between different cables to lower EMI in the first place.

Martin
Dec 15, 2012, 11:01 AM
Engineer for Christ
IBCrazy's Avatar
While for the most part I agree with Martin, I have put toroids on servos and it had no effect on the servo at all. However, as he stated, separation is a key ingredient to success as well as twisting.

-Alex
Dec 15, 2012, 12:28 PM
Registered User
JLT_GTI's Avatar
i have twisted 5 wires..

2X servos (the plane uses 2 servos only) wich are internal and 15cm only

1XESC wire

1XCurrent sensor wire

Theese two come out of the OSD directly to each ESC and current sensor.. i have twisted the part of them that goes inside the plane , since both ESC and current sensor go in a pod over the wings , so i made an internal extension and then plug them from outside.. the only untwisted part is the part that go from both ESC and sensor to fuselage .. but they can be twisted easily tought


Still... if i usually dont have noise , neither in the video or in the controls and only noise in the controls apears ocasionally.. does that discard internal noise (from Video Tx, OSD, etc)?

And if i had that noise with all unshielded wires and still have it with shielded wires?


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