S-video analog?

Thread Starter

Mathematics!

Joined Jul 21, 2008
1,036
Ok I want to make this cord that converts S-video to RCA composite
Both are analog video signals
The directions look pretty simple
Here is the page
http://www.tkk.fi/Misc/Electronics/circuits/svideo2cvideo.html

However I don't know what wire I should use would a regular 22gage copper wire be ok?

And I don't know how long I can make it so it will still work.
I can figure out how much voltage dropped a wire will have by looking up the ohms per foot for the specfic gage wire.

However I don't know what the exceptable min signal voltage that a TV or other standard device needs it to be at?

Also I am curious what type of wire is under the black insulation of an S-video or RCA cord... ? Is it just copper wire with a specific gage or is it bradded like telephone wire is to reduce crosstalk...etc

Would a cat5 ,or telephone wire be ok to use for the cord???

Thanks for any help
 

BMorse

Joined Sep 26, 2009
2,675
If you use the circuit you posted and want to make a cable like the one in your second post, it shouldn't b that hard to use coax, since they are taking both Y & C grounds anyway and both Y & C are also tied together, so use the coax shield as the ground wire, and use the center conductor for the C & Y.

My .02
 

Thread Starter

Mathematics!

Joined Jul 21, 2008
1,036
Ok , perfect thanks

Anyway now that I got all the supplies and am ready to rig it up I have a few last minute questions.

First attached is a picture of a phono-plug (RCA)
Question 1)
I am wondering what metal leg is the ground and which is the signal source???

Question 2)
I am have a problem soldering to the aluminum sheath of the coaxial cable. (i.e the ground of the coaxial cable )
Solder just doesn't hold to this material. I am just wondering how I should go about professional hooking it in... what would the typical way be to make connections to the sheath... I am thinking some copper crimp on coax ring that I can solder on and then crimp on to the sheath....
Just would like to know the best way to go about this with out causeing any interference...????

Question 3)
Attached is a picture of the inside of an S-video connector.
The circled part is the part you crimp on to the coax cable.
Wondering from the pin out their is 2 ground wires and to signal source wires in this S-video connector. But is the crimp part also some kind third ground that needs to be crimped on the the ground sheath of the coax or does it not matter because it is not ground?

What I was think is I may just solder the 2 ground connections into the crimp part and then all I would have to do is make the crimp part attach to the sheath. Maybe that is the way to go ?

Also it just a double check when I look at the 4 pins of the S-video their are 2 bigger pin holes then the other 2. Going by the pinout it looks like the 2 ground connections are the bigger to which is odd to me I thought that the signal would be on the bigger ones. But I am just posting this as a double check let me know if I got it right and the bigger pins are the ground pins.

Thanks Thats about
 

bertus

Joined Apr 5, 2008
22,270
Hello,

The middle pin is the signal on a RCA plug.
The outer side is the ground (shield) connection.

Are there copper strands with the aluminium foil of the coax cable?
You can use the strands to solder it to the outer ring of the RCA connection.

Greetings,
Bertus
 

Thread Starter

Mathematics!

Joined Jul 21, 2008
1,036
The middle pin is the signal on a RCA plug.
The outer side is the ground (shield) connection.
Ok , got that. Thought that was the case just making sure before a start soldering

Are there copper strands with the aluminium foil of the coax cable?
You can use the strands to solder it to the outer ring of the RCA connection.
Well they don't look like copper (goldish strands) but their are some silverish tiny wire strands. Wondering if those will hold on with solder?
Eitherway if they do are they don't it looks like an easy way to make the cable not as durable and easylly breakable using that method.

Do you know if I get some of those coaxial rings you can crimp on do those hold solder? I am basically looking for a really good way of makeing the connection last long under harsh conditions (kids ....etc)

Thanks
 

BMorse

Joined Sep 26, 2009
2,675
at radio shack they have some coax connectors you can get that do not require soldering, the connector just screws onto the cable ends. Usually the aluminum foil is just a shield the small gauge silver wires around the center core is usually the ground. Most crimp on connectors do not require solder, you would just fold the outer shield and ground shield over the outside of the coax and crimp the connector onto it.
 
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