hey guys,

I was wandering if someone had somekind of chart or if they knew themselves and woudn't mind answering the following: 1. will I loose a significant amount of video quality if I put an RCA adapter on the end of a BNC, or any quality?

2. whitch one of the following gives the best quality for short runs?

3. '''''''''''''''''''''''''''''''''''''''''''''''''' '''''''''''''''''''''''''''''''''''''''''''''''''' ''''''''''''''''' long runs?

4. """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""' in general?

5. is it expensive to get an adapter for a video to cat-5 adapter?

6. what kind of quality does cat-5 produce opposed to the other ones?

7. uh, thats it

thanks in advance.

1. You will generally lose 1dB of signal each time you have a connection
your next questions 1-4 aren't really clear... I assume you mean between "BNC_COAX_RCA_S-Video"... BNC and RCA are types of connectors. BNC is generally preferred because it locks on, where RCA could slip in and out easily. S-vid isn't usually great over a long run unless it's on really high quality cable. Also- the connector isn't very well designed - it falls out easily... Coax is the type of cable that almost all video runs over. There are many types of coax, some suited for one job better than the other.

5. depends which type of video signals... there are relatively cheap ones that are just passive adapters basically for most types of video signals. The quality and usable cable length vary between devices. There are more expensive converters for VGA/DVI/HDMI that are active(powered) devices that compensate for skew issues. This is the point that I could go into a long explanation of how it all works and how skew is a problem, but i'll let that go... unless you want to know...

6. other ones? not sure what you mean....

__________________
Pat Rochleau
Evanston Bible Fellowship

you will lose some signal quality over long runs for virtually any type of cable. I know in our experience, anything over 75 feet-maybe 100 depending on the camera-really wants to have a signal or booster amp inline, else the signal seems to get muddy and washed out.

We just started using some passive composite to cat 5 baluns (converters) and they work great so far. I'm sure good quality active baluns would be even nicer-but we got these at around $18 each.

if you use a good RCA there is not much difference to BNC. RCA first was designed for coax cables for easy attachment, and when it was popular in RF/HF market in old days, it was only good enough plug/socket to use for phono (there comes the phono name for plug) connections - and there for became popular in audio use.

I personaly don't like it, nor BNC. Both lack of stability (for moving cables both have glich problems) and robustnes - both are not ment for touring abuse, though BNC is popular and a bit better.

If you buld equipment (or even a pach board) your self, check out other connectors like SMA (it is small, and really good contact).

about sending video trough cat-5, much depends form individual devices (never use pasive ones). For those who are in DIY check out LM7121 IC's. it is not that hard to make one yoursef if you have good skils in soldering (it is smd only ).

No. As others have said there is not much if any difference for RCA vs BNC BUT BNC has MUCH more mechanical rigidity and LOCKS which is a big deal for connections that are constantly being made and remade.

You are mixing up connector types and cabling types here.
BNC and RCA are connector types.
COAX is a type of cable with a spaced centre conductor and shield (e.g. TV aerial cable) and
and S-Video is a way of cabling video signals using separate Y and C cables.

If your question is "what is the best cable type to use over long runs etc." then Video over Cat5 is best for very long runs (100m+) as it uses balanced signalling.

For more info on Cat5 issues, check out this post on my blog.

For shorter runs component (YCrCb) on three separate cables gives the best quality, but most prosumer gear only copes with S-video (two cables - Y and C) or composite (everything down one cable) is trailing far in the rear. Of the latter two S-Video is superior because it gives better resolution and colour quality and avoids the dreaded 'dot-crawl' on graphics and text.

If you are installing cabling I would always recommend installing two COAX runs to allow you to use S-Video if you can.

For more info on using long S-Video cables check this post

Hope that helps

In answer to the question about video (or computer output) to Cat 5 (or Cat 6), one of the best is made by Magenta Research http://www.magenta-research.com/cat5...ansmitters.htm

You will need to do some research to find exactly the right box to fill your application(s).

These are comprised of a transmitter on one end and a receiver on the other. Depending on which transmitter you select, to you can send composite, s-video, even HDTV as well as computer generated graphics down standard Cat 5 or Cat 6 line with virtually no loss. Each box requires local power (wall wart). Lead length can go into miles or certainly within the confines of any church or venue I've used. Another feature that's in the plus column, there is no cross talk between such as nearby power cables. You can use these "boxes" also to feed projectors. They have audio as well as video. Bottom line, they aren't cheap, but they will knock your socks off.

Best Rgds,
Ed