Y/C to Y/C & Composite Converter ?

[Steevg]

Hi,

I wonder if anyone can help me with advice or links to other sites?

 

I'm trying to find a circuit diagram to convert four Y/C signals to four separate (2xY/C - 2xBNC (Composite) - & 2xRC(Composite)) outputs.

So (to explain a little more) - I need to feed four camera's (Sony DSR250P) into a video mixing desk & also provide outputs to a bank of monitors for each camera preview.

I realise DA's would be the way to go, but finances don't allow for this kind of outlay, I'm quite used to building my own equipment, and would be happy to build my own unit if I can find the circuit info.

 

I know Kramer have a single unit ( Kramer 401C ) which "almost" does the trick (Y/C to 2 x Y/C & 2 x BNC), but I'd like the versatility to be able to use "any" Composite or Y/C output from a Y/C input.

 

Also, would anyoneknow what the MAXIMUM length of cable I could use from these camera's (Y/C) is - before suffering serious signal loss.

I'd prefer to use IEEE1394 but unfortunately the video mixer we're using is a low cost unit (read "cheap") and only has the facility to I/P two Digital signals maximum, so I'd prefer to keep all the I/P signals the same - ie: Y/C.

Also I believe that the maximum length of IEEE1394 is around 125 feet, can you confirm/correct that statement too ??

 

I'm helping to wire up a small rack with a vision mixer & monitors for an amateur production in New Zealand.

 

Any help/links anyone may be able to provide would be MOST helpful.

 

Kind regards,

Steve

[paulears]

I've had y/c work fine down 50m - not tried more than that. I have noticed sony mentioning that the firewire out from their pro cameras is not designed to go direct to a mixer (even though they sell them) and gliches are a normal design feature. Sounds like a buffering issue.

[david.elsbury]

Can you live with black & white preview? Then you could use a composite VDA and just split the 'Y'. I saw a site on the interweb thingy a wee while ago which used a couple of transistors as a VDA... not sure of the quality though.

 

I've seen Y/C run over RG59 coax for 70m with no probs, this being straight out of a computer.

[henny]

Can you live with black & white preview? Then you could use a composite VDA and just split the 'Y'. I saw a site on the interweb thingy a wee while ago which used a couple of transistors as a VDA... not sure of the quality though.

 

I've seen Y/C run over RG59 coax for 70m with no probs, this being straight out of a computer.

<{POST_SNAPBACK}>

 

 

to get comp from y/c just combine them, not the best in the world but fine for preview.

 

I would never use IEEE1394 for live screen work, too much delay,can be anything between 2 and 4 frames,beacus nearley all vizion mixers convert back to component to do the mixing then back to dv.

 

ian

[david.elsbury]

to get comp from y/c just combine them, not the best in the world but fine for preview.

 

I would never use IEEE1394 for live screen work, too much delay,can be anything between 2 and 4  frames,beacus nearley all vizion mixers convert back to component to do the mixing then back to dv.

 

ian

<{POST_SNAPBACK}>

Yes, however to get composite and s-video outputs from the one s-video source, you would have to use a dist. amp- because you would effectively be shorting together one part of the Y.

 

Plus it's not just as easy as combining them, you need to pass it thru a capacitor (see http://www.epanorama.net/circuits/svideo2cvideo.html)

[James]

Hi,

I wonder if anyone can help me with advice or links to other sites?

 

I'm trying to find a circuit diagram to convert four Y/C signals to four separate (2xY/C - 2xBNC (Composite) - & 2xRC(Composite)) outputs.

So (to explain a little more) - I need to feed four camera's (Sony DSR250P) into a video mixing desk & also provide outputs to a bank of monitors for each camera preview.

I realise DA's would be the way to go, but finances don't allow for this kind of outlay, I'm quite used to building my own equipment, and would be happy to build my own unit if I can find the circuit info.

 

I know Kramer have a single unit ( Kramer 401C ) which "almost" does the trick (Y/C to 2 x Y/C & 2 x BNC), but I'd like the versatility to be able to use "any" Composite or Y/C output from a Y/C input.

 

Also, would anyoneknow what the MAXIMUM length of cable I could use from these camera's (Y/C) is - before suffering serious signal loss.

I'd prefer to use IEEE1394 but unfortunately the video mixer we're using is a low cost unit (read "cheap") and only has the facility to I/P two Digital signals maximum, so I'd prefer to keep all the I/P signals the same - ie: Y/C.

Also I believe that the maximum length of IEEE1394 is around 125 feet, can you confirm/correct that statement too ??

 

I'm helping to wire up a small rack with a vision mixer & monitors for an amateur production in New Zealand.

 

Any help/links anyone may be able to provide would be MOST helpful.

 

Kind regards,

Steve

<{POST_SNAPBACK}>

 

If you are doing this on the cheep then don't bother with DAs at all.

 

You say that you are happy to modify your equipment, Assuming that there isn't a loop output on the vision mixer then how about removing the termination resistor on the Y path into the mixer, wiring up a simple loop out (to which you could always add a switch or external terminator if you wish) which you can then pass to your preview monitor.

 

Why the Y conponent only?

 

Beccause one assumes that your preview monitors can't take YC, and Y has picture and syncs so is enough to see preview on.

 

Why pass through the vision mixer rather than running the Y through the monitor first?

 

So that the monitor shows post vision mixercabling, any problems should be aparent on the monitor, the other way arround gives the possibility of faults going un noticed.

 

It doesn't need to be said that 4 1x4 YC DAs or 8 1x4 composite DAs would be much better for this project. You might be lucky and find someone throwing out composite DAs - I know we have done recently

 

James