Scottish Elises

Second scrounge of the week. Putting together a CCTV system for someone who is having some neighbourly problems and realised that I have given away all my spare desktops! Anyone for a Dual core or above desktop going asking?

S

I'm sure I can rustle something up. Even got a spare basic CCTV card.

Awesome cheers, its only a 2 cam setup. Was going to try one of those USB cctv dongles, do they do the 264 encoding prior to shunting it up the USB cable as was worried about USB bandwidth.

S

The card is a 4 cam non HD solution. Would allow you to work with older hardware

It take balun connections?

S

It's got BNC connections ya balloon. /me goes to look up what Balun connections are.

That's what I meant!

Balun is a contraction of balanced/unbalanced. Typically found anywhere you have a balanced network on one side and a single ended/unbalanced one on the other side. ISDN2 had such things if I remember correctly, typically built into the home highway style termination I think. You'll also find them in audio circuits, e.g. for certain types of microphones.

Cheers,
Robin

That may explain the wavy line interference I have on one cam using a balun. I thought they were simply bnc connectors with easy to use terminals!

I don't think you need a balun for CCTV unless you have a deliberate change in impedance somewhere, e.g. by mixing cable types like long runs of Cat5/STP instead of coax because it's cheaper. At that point you'd use a converter with a built-in balun. CCTV cameras all have a source impedance of 75ohm, so as long as you're using 75ohm coax then a bog-standard camera->cable->card circuit is fine without a balun.

Define long run? I am using CAT5 and using some pairs for 12v.

S

Doesn't matter how long... what I meant was that a long run might be one reason to use Cat5 in the first place. If you decide to use it at all, it doesn't matter how long the run is, you'll instantly have an impedance mismatch as it creates a standing waves and reflections when the RF whizzes along the 75ohm coax then bumps into 100ohm Cat5.

If the picture looks fine, leave it. If not, you'll want something like this at both ends of the Cat5 signal pair: http://www.amazon.co.uk/kenable-Video-E ... B0051FKI1K

Try it without... this is all theory. I can't believe anyone uses analogue cameras at all... IP was invented, like, 5000 years ago

i have a few old dell precisions sitting doing nothing... mixed bag of stuff but they are old render nodes which cant contribute to the render farm anymore. generally dual/quad sing or double CPUs.

BTTT looking for some desktops dual core or quads if available! TIA!