the toss

I'd hardly call that a side note. When you say you get "video loss" do the words "video loss" actually appear on the screen?

Baluns are simply BALanced to UNbalanced impedance matching transformers that matches a 75^ camera O/P to a 100^ transmission line (Cat 5/6 ) & then back to a 75^ I/P at the DVR. By using a balanced transmission line you get all sorts of noise rejecting properties which may or may not be of benefit. Some people swear by the use of Cat 5/6 while others prefer to stick with RG59. Keep in mind that while Cat 5/6 has a lower loss /m than RG59 the simple use of baluns will itself result in an insertion loss depending on the quality of the balun. My biggest problem with baluns it the physical fragility of the terminations. Have a look behind some 16 ch DVR installs & it is a nightmare. Imagine instead of robust RG59 & BNC connectors , the terminations in that mess were a pair of cat 5?6 wires on a screw or insert connection. The ONLY time I use Cat 5/6 is when it can be terminated at a patch panel & RG59 patch leads can be used.

You are right about it being power. The power is dropping its bundle when the IR leds turn on. This is causing an amplitude drop of the frame sync pulse. The VGA monitor has a digital I/P which has been cleaned up & regenerated by the DVR. The LCD monitor has to make do with an analogue split before the DVR does its compession/storage. Beef up your power supply & the trouble should disappear.

While the solution that Owain has given you is fine in theory ( & quite workable for a fixed current) you will have the problem of two different current demands. There will be the standard operating current & then there will be the current under ptz operating conditions. The second will cause a greater voltage drop than the first due to increased current requirements. In these conditions the "overhead" voltage from your supply will be quite a balancing act & may not be possible.

are you talking $100 , $1000 or $10000 cameras ?

I can't see these brown chequered blocks you refer to in those thumbnails. It does appear that you have a overly wide angle lens that is causing the "fisheye" distortion ( 2mm perhaps) You should concentrate on the area of interest & not try to capture everything to the horizon. The youtube clip shows a camera that is in need of some chroma correction. The yellow is breaking through.

There is hardly a camera ever built that actually lives up to the sales pitch. That is not to say they are all rubbish , just that it is in the genes of a salesman to exagerate , they can't help it. If the camera you purchased doesn't live up to the description then send it back. If you got it off ebay then you should've known better. There are lots of low cost cameras that do a really good job but I stick to known manufacturers/distributors with a known quality product. What I do do with people who are very price sensative is find these cheaper cameras & let them know that they are not a camera I have ever used & cannot vouch for their quality. Sometimes they opt to go with the cheaper camera & take responsibility for the results. This way I get to try these cameras & have often discovered some that I have continued to use.

Thanks - I didn't look at his link but gave some general info on power supplies for his education.

Ideally the power supply should be regulated. This means that the output voltage will not vary over the range of current it is designed for. A 12 V unregulated supply may have an output voltage as high as 18v when little or no current is drawn & not output 12V until the nominal load is applied. A regulated power supply will be labeled as such

OK , I'll be sucked back in just once. CCS cable will work on RF systems over short lengths but don't sit there wondering over problems you may get. Anyway cctv systems are not RF. 25Hz (30Hz) is not the vertical sync it is the frame rate. I wouldn't waffle on about the DC & 30Hz characteristics of coax when you are ignoring the horizontal sync of 15.75 Khz & chroma signal of 3.58 Mhz. If you want to talk qualifications - Electronics & Communications Deg (specialising in Transmission systems) 5 yrs of electronics design 11 yrs of Transmission systems (analogue & digital) 7 yrs of Microwave Radio transmission systems 17 yrs of security electronics (my own business) See , I told you it would become a slanging match Forgot to mention - the world didn't end so be happy & have a great Xmas.

Copy & paste from "transmission Engineering Principles" Despite being shielded, interference can occur on coaxial cable lines. Susceptibility to interference has little relationship to broad cable type designations (e.g. RG-59, RG-6) but is strongly related to the composition and configuration of the cable's shielding. For cable television, with frequencies extending well into the UHF range, a foil shield is normally provided, and will provide total coverage as well as high effectiveness against high-frequency interference. Foil shielding is ordinarily accompanied by a tinned copper or aluminum braid shield, with anywhere from 60 to 95% coverage. The braid is important to shield effectiveness because (1) it is more effective than foil at absorbing low-frequency interference, (2) it provides higher conductivity to ground than foil, and (3) it makes attaching a connector easier and more reliable. "Quad-shield" cable, using two low-coverage aluminum braid shields and two layers of foil, is often used in situations involving troublesome interference, but is less effective than a single layer of foil and single high-coverage copper braid shield such as is found on broadcast-quality precision video cable. You are distorting my words. I have not said that foil does not block interference. What I said was foil shielding was not particularly effective at CCTV baseband frequencies , it was designed for UHF. Skin effect is irrelevant to the disscussion & only comes into effect (to any great extent) above a couple of hundred Mhz. The whole purpose of the drain wire is to provide a "reliable" signal earth since aluminium foil is a totally unreliable conductor especially at the termination points. You talk about the foil needing enough copper to provide a "return" for the signal. You seem to be confusing your DC fundamentals with your transmission principles. We are talking negligable current for a 1Vpp composite video signal. Why do you worry about DC resistance on a transmission line that is transporting a 5.5Mhz signal & where did you get the idea that CCTV operates at 25 - 30 Hz. All this cable is designed for a purpose & all have specific limitations. Work within the design parameters & you should have no problems. Use cable NOT designed for the job & it may work with varying degrees of success depending on the demands you place on it . Now that you have informed me that braided shield RG6 is produced I'll go back & modify my original position. RG6 with foil shield is "not the best choice" for CCTV usage. I'll not continue with this thread because any thread that narrows down to two participants with differing views inevitably become a slanging match. The ccs cable you talk about is simply a con job pulled on the consumer probably by the same people that sell the 3" computer speakers that handle 500W each.

Got up this morning & decided that there was no point in having breakfast since I probably wouldn't have time to finish it before the event. Got to 11am & I was starving so I thought I would hit the net to find out what time it was set down for. No one seemed to know. Then I realised that if the end of the world was happening on the 21st in America as well then it would have to be pretty late in the day in Australia. I bet the other mob that believes an unknown astroid will obliterate the earth in February are peeved that they have been beaten to it by the Mayans

So there we go. You can get CATV RG59 & CATV RG6 as well as CCTV RG59 & CCTV RG6. If the RG6 is so perfect why do they make a Foil shield version & a braided shield version. What is the difference that requires both to be made. My initial point (which you seem to want to ignore) is that foil shielding is designed for higher frequencies than CCTV baseband & whilst it "can" be used it can also be the source of problems. The only advantage it offers to CCTV use is its lower attenuation . As for using RG11 - why would you even consider it. If long runs are required then just use basic transmission engineering principles. Pre & post equalisation & amplification to requiremnts can get you a couple of kilometers for very little cost. UTP has the problem of physical fragility ( especially at the termination points) unless it is terminated at at patch panel using standard data cabling techniques. As they say - " there is the right way to do things & there are the other ways"

Looking at the specs you posted I would say your example RG6 is not a generic type but a high end specialist manufacture - hence the cost. For off the shelf generic RG6 (which is what most end users will buy) -- dB/freq per 100m 4.9dB @ 50Mhz 6.9dB @ 100mHz 14.4dB @ 400Mhz 19.7dB @ 1 Ghz Specs for RG6 are not normally quoted under 50Mhz since it is NOT recommended to use it at the lower frequencies. Again you seem fixated on attenuation & how far the run can be.

When I say it is not a question of attenuation I'm referring to the point that I am making. Everyone is focused on the attenuation characteristics & that is it. What I'm saying is that there is other design parameters that should be considered. Even the simplest of minds would realise that if RG6 was so much better than RG59 then RG59 would not still be made. RG6 was made for a purpose & that is UHF digital RF I have never seen braided RG6 but then again I don't work with RG6. It would be interesting to see the specs

If this setup is something you just want to play with then go ahead & buy the cheap stuff , fiddle with it & learn as you go. If on the other hand it is to fullfill a purpose then you need to buy gear that will have the desired outcome. It may be more than you want to pay but you have to weigh up the cost to the need. BTW you have already wasted $20 for a camera that is useless , $13 for a capture card that is useless & probably $10 for a multimeter that is useless.

It is not a question of signal attenuation but one of RFI rejection. RG6 uses foil tape shielding which is not all that effective below about 40Mhz

Buy cheap and buy often. You are simply wasting your money

I've used it before from the DVR spot monitor output to a LCD TV with a BNC fitting on one end and a RCA on the other to the composite input of the TV. Quality wasn't bad but do you think it will affect the picture quality of the camera's to the DVR? Yes it works & there are probably thousands of installations using it. Howeve the design parameters are different & there are problems that can be due to using RG6. Put it this way - if you already have RG59 you will gain nothing by replacing it with RG6

RG6 is desiged for UHF RF signals not composite cctv signals

It is probably not regulated

This section doesn't seem to get a lot of use but I'll try my luck before going elsewhere. My daughter is coming to your sunny shores over Xmas & will be in LA & San Diego. What type of power outlets are used ( 2 or 3 pin) & is it all 120V ?

Apparently the plasma cutter is essential for her hair

If you have room on the rack ( 1U ) then install a patch panel with panel mount double female BNC. Then make up a bunch of 15' patch cables. This will not overcome your problem with insertion loss which will remain at about 1.5dB but if this is of importance then you have other design issues to address

What a nightmare of a system