survtech

The way to do that is with a shop vac and a pull string attached to a foam ball or a "conduit piston". essentially, you attach the vacuum to one end of the conduit and pull the string through with it. Make sure the conduit piston is just slightly smaller than the conduit.

Another difference between a quad and a multiplexer is that a quad always puts the four cameras into quadrants so each picture would be 352x240 or 320x240, but the recording would be at full fps (up to 25/30). A multiplexer normally sends each camera to the recorder in sequence so the resolution of each camera would be higher, up to 720x480 but the frame rate for each camera is typically 1fps or less.

You could add a terminator using a "T". Not the most elegant solution, but if it works...

OK, but if you really want to get fancy, use the pill bottle splice.

I can't comment on most of your post but I suggest using LCD monitors, rather than DLP. Most DLP TVs use a lamp whose life is typically 4,000 to 8,000 hours, That's only 6 months to a year in 7/24-hour operation. An LED DLP would have a longer life, though. On the plus side for DLP, they often have a better field-of-view so the picture won't fade as much as the viewer goes off-center. They are also cheaper than large LCD.

For video, CAT5 splices are fine if done right. We use "beans" on the wires after stripping them and twisting them together and it works fine. Just make sure you maintain the "twist" as much as possible. That's for individual cable splices. For our 25-pair backbone to 4-pair connections, we use "66" blocks.

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It could be, but you also may see the video jitter and/or lose sync. It depends on a number of factors: the length of the coax, the output of the camera, the sensitivity of the monitor or DVR, etc. In some instances, it may not be very noticeable unless you A-B compare the camera with a short run or the correct cable type versus a the same camera with a long run of incorrect cable.

A number of companies make these. Do a web search for "USB video capture" or "USB video adapter". Here's one from StarTech: Since most of them have RCA connectors, you would also need a BNC-to-RCA adapter.

The primary problem will be the DC resistance of the cable. Comparing two Belden RG59/U cables, for instance: Belden 1426A and 8212 have very similar specs except the 1426A has a pure copper center conductor while the 8212 has a copper-clad steel center conductor. The DC resistance of the 1426A is 10 ohms per 1000 feet while the DC resistance of the 8212 is 44.5 ohms per 1000 feet. This will cause the video signal to attenuate faster in copper-clad steel cable, reducing the length you can run before the picture is affected. When you add the factor of "skin effect", where low frequencies travel in the center of a conductor but higher frequencies tend to travel in the outer area, the result of using a copper-clad steel cable will be a higher attenuation of the low frequency components of the video. This can cause poor sync stability and exaggerated high frequencies which usually affects the color signal. Both of the above examples have woven copper shields. The DC resistance of the copper shield material is 2.6 ohms per 1000 feet. Belden 1186A is similar to 8212 except it has an aluminum shield. Its shield's DC resistance is 7 ohms. This will even further limit distance capabilities. While RG6/U would experience less loss overall due to its larger center conductor (18 gauge versus 20 gauge), it will still attenuate the signal faster than copper/copper RG59/U. An example would be Belden 1189A, which has 18 gauge copper-clad steel center conductor and aluminum foil shielding. The center conductor is 28 ohms per 1000 feet and the shield is 4.8 ohms per 1000 feet; not nearly as good as the 1426A RG59/U.

You might want to start with a Pelco protocol development kit. I suggest you contact Pelco directly for some help with this. Here is the link: http://www.pelco.com/sites/global/en/sales-and-support/support-services/obtaining-pelco-protocol.page?.

The difference is that RS-232 is a protocol that uses one pin for Tx+; a second pin for Rx+ and a common ground pin. That is a prime reason for its distance limitations: it is basically an unbalanced signal. RS-422/485 has separate pairs for transmit (Tx+/Tx-) and receive (Rx+/Rx-). It is a balanced signal and, as such, is far more immune to noise and grounding issues and therefore able to travel much farther. Most PTZ functions only require one-way data - control signals going from the controller (Tx +/- port) to the PTZ (Rx +/- port), so that would be all you would need. Connect the (+) at one end to the (+) at the other and the (-) at one end to (-) at other.

I'd be willing to take it off their hands for a few quid!

It's interesting to see that the BBB gave MagicJack an "F" rating until the company joined the organization (read paid the fees); then changed MagicJack's rating to an "A-". It is plain evidence of something I've believed for years: the BBB is not in the business of protecting consumers, rather it is in the business of charging fees for BBB membership.

lengfeng203, As a manufacturer, perhaps you could explain why no LCD display manufacturers make a monitor capable of displaying interlaced video properly interlaced, rather than deinterlaced?

We prefer the kind with IDC connectors on the balun, rather than having to install RJ45 connectors. That's very true. The other side of that coin is that CRT monitors are becoming increasingly difficult to obtain; in large part because most manufacturers have discountinued production of the CRTs. We were going to buy some Samsung SMC-213 monitors this year but they were discontinued and the replacement (SMC-215) is 3.6 inches taller. They wouldn't fit in our racks. We wound up buying Orion 19RTC LCDs. They had pretty much the best LCD picture with analog inputs. On a side note: I really don't understand why manufacturers can't or won't make an interlaced LCD monitor. AFAIK, it is technically possible to interlace flat panel displays. Oh, well. In the future, all sources will probably become progressive scan and interlacing/de-interlacing will become unnecessary.

SonyStyle has a flush-mount 6.5" monitor, Model # XVM-H65. It's made for vehicles but could be adapted for a wall. Other companies also make flush-mount monitors for vehicles. http://www.sonystyle.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10551&storeId=10151&langId=-1&productId=8198552921665258907 Also, VMP makes flush mount adaptors: http://www.videomount.com/LCD-F.htm http://www.videomount.com/LCD-FT.htm

John Honovich's IP Video Market Info (http://ipvideomarket.info/), CCTV Labs (http://www.cctvlabs.com/), Video Surveillance Guide (http://www.video-surveillance-guide.com/), Info4Security (http://www.info4security.com/section.asp?navcode=127). Try a web search for "cctv systems reviews".

fas, It actually depends on the local building code and how hardcore inspectors are. You should check with the local Planning and Zoning commission or building inspectors.

OK, now I get it!

Or network two DVRs. Many units are capable of doing this.

+ 2 - and I would avoid them for any installations. They do tend to come loose!

Not really. You can almost always use a lens made for a larger imager on a smaller imager, just not the other way around. The image would not fill the screen, like tunnelvision. The only minor downside is that it is harder to find wide angle lenses for the larger imagers. You can find standard (not megapixel) lenses for 1/3" cameras down to 1.6mm or so. It's rare to see 2/3" lenses lower than 8mm. A 2mm lens on a 1/3" camera would give the same field-of-view as a 2.6mm lens on a 1/2" camera or a 3.6mm lens on a 2/3" camera. You do have to watch out for lens mounting types, though - "C" mount and "CS" mount lenses are not interchangeable. You can use a C mount lens on a CS mount camera with a 5mm spacer (C-to-CS adapter) but you can't use a CS mount lens on a C mount camera. Most modern analog cameras are CS mount and megapixel cameras tend to be C mount.

These are among my favorite covert lenses: High Tech Pinhole Laparoscopic Lenses Lots of other options too. Look up "covert cameras".