TomHoward Posted November 12, 2015 Share Posted November 12, 2015 Afternoon all I am looking at tidying up our video relay and MD cams. At the moment the system is based on composite, and runs over a mix of composite tie lines and CAT5 with Muxlab passive baluns.Some of the CAT5 lines are pretty long and doesn't result in a great picture quality at all. The show relay TVs can be in various locations depending on show and the CAT5 runs can be pretty round the houses, sometimes popping up via the IT network patchbays. The distribution can be a bit of a mess with standalone composite splitters (4 way black boxes and the like) by the patchbay, to break the incoming video (either via composite tie or over a balun and back to composite) into many baluns going off around the place. The camera is a fairly cheapy CCTV type but the picture out of it is better than the distro system allows. TVs are all LCD and have the usual composite, HDMI and VGA on all. I'd like to tidy it up onto one type of system, and the most obvious is to put in a video matrix like a Kramer 828 or similar, and pull composite all over the place, but it seems like that might be a bit of a dated way of doing it?Is there anything else I should be pulling instead, like active baluns over CAT5, or any kind of digital? Link to comment Share on other sites More sharing options...
Whiskers Posted November 13, 2015 Share Posted November 13, 2015 Avoid all things digital - LATENCY builds up very quickly, at least one frame (1 / 25 second) for every digital process. Your camera probably puts in a bit of delay. can you bring all the possible video destinations to one place, if ao a better Video Distribution Amplifier (VDA) that has adjustable gain and EQ for each output you can then set each branch to optimum quality. Link to comment Share on other sites More sharing options...
TomHoward Posted November 13, 2015 Author Share Posted November 13, 2015 Would you still be doing that in composite over coax in this day and age or is that outdated?We could pull in a load of new coax to avoid baluns, but it seems that might be a bit backward these days? Link to comment Share on other sites More sharing options...
timsabre Posted November 13, 2015 Share Posted November 13, 2015 Would you still be doing that in composite over coax in this day and age or is that outdated?We could pull in a load of new coax to avoid baluns, but it seems that might be a bit backward these days?I wouldn't worry about being modern, just use the best solution... Cat5 with baluns has a number of advantages - the cable is cheaper (though this will probably be offset by the cost of the baluns), and it can potentially be used for other purposes (though if this is a fixed install then it never will be). There may be already cat5 in place which you can use. Also the baluns give you effectively a balanced line which can reduce earth-related hum bars and noise pickup. On the other hand the quality might not be as good as a direct coax connection depending on how good your baluns are. Link to comment Share on other sites More sharing options...
Brian Posted November 13, 2015 Share Posted November 13, 2015 You could go for a mixed solution if it better suits your infrastructure. For show relay into dressing rooms and public areas a frame or two of delay doesn't matter. But as others have said, for MD relay and probably SM relay you want composite. Link to comment Share on other sites More sharing options...
TomHoward Posted November 13, 2015 Author Share Posted November 13, 2015 Are the passive baluns up to the task and ours are just wearing out?It'd also be good to find a system that let us split in CAT5 after the balun if we were using baluns - at the moment we generally have two sources, which go to about 4 monitors each, so it needs two baluns for each end of the 4 runs I might look at something like a 8x8 switcher, (scaling down from that size tends to find less outputs rather than less inputs), but break the outputs out to a mixture of patchable composite outputs and CAT5 outputs with the baluns installed behind the patchy in the rack - to tidy up the installation Link to comment Share on other sites More sharing options...
timsabre Posted November 13, 2015 Share Posted November 13, 2015 Are the passive baluns up to the task and ours are just wearing out? Can you describe "doesn't result in a great picture quality at all" in a bit more detail? I would go round with a good quality composite monitor (CRT ones are on ebay for under £20 now) and plug it in at various stages of the chain to see where the quality loss is occurring. You may well just have one or more bad terminations. Link to comment Share on other sites More sharing options...
Whiskers Posted November 13, 2015 Share Posted November 13, 2015 Regarding old and pull in more cable and being old If you chose the right Coax you can run HD SDI or Composite down the same cable = that will up res you in the future if you ever need it. best if you are running cable infrastructure to put in both cables - cost is peanuts compared to your time and trouble running them out. Link to comment Share on other sites More sharing options...
TomHoward Posted November 13, 2015 Author Share Posted November 13, 2015 The pictures are mainly fussy, with a lot of snowflakes / static - the camera isn't the best, but a monitor put at the camera has a much better image than a monitor at the other end of the cable run. We have some CRT monitors still (they aren't worth selling basically) but I haven't checked multiple points along the run. This tends just to be generally though rather than any specific run. There are a lot of points to go wrong in the balun run as well - so fault finding takes a fair but longer as there are several cable types involved. What coax should we be pulling for long composite runs in this kind of environment? Link to comment Share on other sites More sharing options...
Peter F Posted November 13, 2015 Share Posted November 13, 2015 Are the passive baluns up to the task and ours are just wearing out? Some baluns are better than others. Oddly, with the passive ones the quality to price relationship is not always as predictable as you would expect. I can heartily recommend these: Balun King 4 way. You can also use them for audio (just buy some phono>BNC adapters for about 50p each from CPC) or a mix of both video and audio. I've used all sorts of passive baluns over the years from £1.50 CCTV Ebay specials to Intelix £80 ones and these Balun Kings have proved to be the best in terms of both quality of picture and reliability. Cheers, Peter Link to comment Share on other sites More sharing options...
TomHoward Posted November 13, 2015 Author Share Posted November 13, 2015 Thanks for that PeterIs that true of the smaller BalunKing as well - the single and 2 channel ones?Most of our stuff is distributed around the place so we very rarely need to send 4 video ties over one line. I'm fairly sure you can't because the impedance is wrong, but you can't run those baluns over low impedance cable could you? We have XLR ties everywhere if there's any viable way to send video over XLR. Link to comment Share on other sites More sharing options...
sleepytom Posted November 24, 2015 Share Posted November 24, 2015 Avoid all things digital - LATENCY builds up very quickly, at least one frame (1 / 25 second) for every digital process. Your camera probably puts in a bit of delay. can you bring all the possible video destinations to one place, if ao a better Video Distribution Amplifier (VDA) that has adjustable gain and EQ for each output you can then set each branch to optimum quality. This is not true. It's completely possible to build low latency digital systems. In today's world of HD resolution screens you'll find that native resolution digital inputs are normally lower latency than analog SD inputs (which must be digitised, deinterlaced and upscaled before they can be displayed) Things such as SDI to HDMI converters do not add anything greater than a single line of delay. --- I would suggest you aim for a future of HDSDI - pull decent coax to replace your cat5 - you can run composite down this cable until you are ready to swap the camera for an HDSDI CCTV cam and add HDSDI to HDMI boxes at your screens. Using a good cable designed for HDSDI will give you no problems with runs upto 100m. Spending any significant sum of money on analog / SD kit at this point in time would be insanity. Link to comment Share on other sites More sharing options...
TomHoward Posted November 24, 2015 Author Share Posted November 24, 2015 Tom Would you be able to advise the kind of units we'd need for HDSDI and SDI to HDMI?What kind of coax would we be looking at? Thanks, Tom Link to comment Share on other sites More sharing options...
Stuart91 Posted November 24, 2015 Share Posted November 24, 2015 Avoid all things digital - LATENCY builds up very quickly, at least one frame (1 / 25 second) for every digital process. I suspect what you mean is that any frame synchroniser (a mixer or switcher combining non-genlocked sources) is going to add at least one frame of delay. Other digital processes can run a lot faster if you buy the right kit. Link to comment Share on other sites More sharing options...
Dave m Posted November 24, 2015 Share Posted November 24, 2015 just search for HD-SDI cable ( and connectors) when I speed out a building it was actually cheaper to use HD-SDI than composite cable I use blackmagic HD-SDI to HDMI boxes http://www.rcblogic.co.uk/p-3714-blackmagic-sdi-to-hdmi-4k-converter.aspx I guess you can use cheaper chinese knock offs if you are willing to risk a problem. Link to comment Share on other sites More sharing options...
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