Fiona

Cat 5 cable consists of 4 pairs of 24 AWG wire which is preferably stranded copper. Each of the 4 pairs are twisted to increase the current carrying capacity. And the twists vary in number to avoid ‘crosstalk’ between each pair. The impedance is rated at 100 ohms, though individual 24 AWG wires seem to be rated at 76 ohms which is close enough to the RG59’s 75 ohm impedance rating. The practical limit in length for CCTV applications is about 300’ as opposed to the RG59’s which is 750’. Question: The RG59 was originally a military specification cable. It is so massively overbuilt in comparison to a Cat 5 - and yet this marginally constructed Cat 5 is capable of conducting a video signal over lengths long enough for most installations. What is the theory that explains the capability behind an insubstantial 24AWG pair (100Ω) to carry a signal that was once the domain of RG59 and RG6? What happened to the 95% copper shielding and the dielectric core? The SCC is about 6mm in diameter and the signal travels along the outer microns; and this was replaced by about ½ mm diameter 24AWG. Any explanations?

Thank you Soundy, Rory and Tom for the technical explanations. I don't want to wear the Integrators out, so I will do some individual research on the phenomenon of unbalanced vs. balanced signals and how the balun affects the later.

Perhaps this was already mentioned, and I just missed it: Why was RG59 used for the last umpteen decades if simple 24AWG would have sufficed? In the Age of Ecology, think of the difference in copper consumption between the two types, not to mention the increased consumption of oil-dependent plastics.

Soundy, so you're saying that the baluns are the key component to the Cat 5? In other words, any length of 24AWG (100s of feet for example) would be capable of conducting the signal provided baluns were used?

You seem to be emphasizing the point I was making. If Cat 5 can run 2200', what was the point of using RG59? What is it about the design of Cat 5 that allows such high returns for comparitively small amounts of material?

Cat 5 TC-L2 uses 22AWG and the specs claim additional shielding at Cat 6. See: http://www.wisp.net.au/pdf_datasheet.php?products_id=429 This is still very close to the original Cat 5 specifications. The TC-L2 uses 22AWG with a .065 mm diameter yet it achieves four times the signal conducting distance of 24AWG.

To our dear friends in China, especially Guangdong and Shenzhen, as well as Korea, Vietnam and Japan All the Best for the Lunar New Year. Gong He Xin Xi - Happy New Year for the 23rd of January 2012. And to the workers in the EPZs; the R&D specialists and the wholesalers in Asia who build, develop and export the equipment, have a great Year of the Dragon. Chuc mung toan bo nguoi Viet Nam van song o nuoc que huong minh va nhung nguoi Viet song o nuoc ngoai mot nam moi vui ve.

A couple of thoughts: What is the brand name of the DVR? I presume you were using all 8 channels? As a general rule, it is pragmatic to build redundant capacity into any system - cameras; PCs; DVRs etc. By 'redundant capacity' I am suggesting that you must always anticipate technical failures irrespective of the cause. If the DVR had, say, double the necessary channels, thereby some redundant capacity, the loss of two channels would have been irrelevant to the immediate operational capacity of the system. By the way, I hope it is a DVR that is popular with members on this forum. If it is, you can be certain that such an odd failure will rouse the curiosity of those loyal to that brand.

Chesterfield, I will try to keep this simple for your benefit. (1) The subject of this thread is lofts and those areas which fall under the rubric of ‘roof spaces’ such as above ceiling cavities and empty uppermost voids; as well as structured, framed areas and other generally non-habitable hollows or nooks directly beneath roof tiles, sheets or rolled tar membranes. This thread is categorically not requesting an analysis of the security implications arising from an interloper’s access into basements, ground floors, first floors, garages, conservatories or outbuildings to which you so confidently allude. If you are so interested in these areas irrelevant to this thread, then I encourage you to start a separate thread about securing a DVR within habitable areas of a building. (2) The proposition that is implied in the title is that lofts are infallible places to secure DVRs. Dub Thing’s post is requesting objections to test any areas of fallibility which he may or may not have considered. (3) My initial reply challenged that infallibility. N.B. It is not the quantity of posts that matters, so much as the quality of each post. I am now finished with this thread.

According to official crime statistics, in approximately thirteen percent (13%) of all house break-ins, entry is gained via the roof. So it would be bitterly ironic if, having squirreled your DVR safely amongst the rafters, a burglar should luck upon it up there.

For what it’s worth, the Kings BNC Model Number: KC-59 294 range of RG59 crimp on BNC connectors are a work of art. They were exquisitely machined and precision made in the US many years ago. They used a small T-piece heat resistant washer to line up the BNC pin with the RG59 core. This detailed washer fitted hard against the dielectric insulator so that the dielectric insulator sat on one side with the soldered pin on the other. The ferules too are of a high quality; being about ½” long and exceptionally sturdy. Kings BNC connectors originally retailed, as I remember, for around $9.00 each US. New Old Stock is only available today, with prices at about $2 to $3 US. Given the quality of the Kings BNCs, it should come as no surprise that the company went out of business many years ago. Cheaper imports and more popular twist-on fittings eroded Kings’ market share until the inevitable cessation of business.

The raw aluminium threads on the Spectra Back Boxes look like they'd easily corrode when threaded into the mounts - IWY; pole mounts etc. Question: What product or method is used to prevent those threads from corroding when installed in wet, damp or humid locations? What does Pelco recommend?

Thanks Soundy, if corrosion isn't an issue at your lattitude then I guess it shouldn't be a problem. Thread tape crossed my mind, along with transparent grease. Hardwired, that's a terrific annecdote about Pelco recommending and providing Loctite and then having to eat their words with a free arm and BB replacement.

So the a budget of $800 is for the speed dome alone? In other words, you already have: (i) the keyboard controller (ii) the power supply (iii) a DVR (iv) wall/pole mounts (v) the necessary cabling installed And you intend to install it yourself presumably?

Come to think of it, there was a woman about a year ago who had a gigantic scanner nailed to her front porch. You guys don't live in the same street by any chance...?

myplace46 wrote: (1) You can always use the wheel on your PC Mouse to magnify the entire screen image. (2) I imagine a Goldwing piloted by a rider with poor eyesight would be potentially lethal. (3) Some Pelco scanners such as the PT270 were built for indoor use only. By the appearance of your scanner, it seems never to have been installed outdoors.

Er, check out the power consumption of those Pelco units, then multiply that by 8760 hours per annum times, say, three years in operation and you will quickly find that the efficient DVRs pay for themselves.

Have you considered the Samsung range of consumer grade DVRs?

Oh, if it were all only that easy... Unfortunately it is not really possible to say that a single brand can achieve the highest quality with the greatest reliability. Your criteria of "quality" and "reliability" is dependent on the specific nature of the application. i.e. what objectives you need to satisfy with any proposed system. For example, if your CCTV is to monitor machines in a factory, the brands suited to this would be different to a nanny cam in the basement or mobile surveillance in a vehicle. It is all very well to name the established brands, but not even all of those can necessarily produce an outstanding product without becoming very expensive. For example, if you need medical imaging, you might want to consider a Mitsubishi DVR or some other DVR that uses the JPEG2000 format. The Mitsubishi's aren't quite so user friendly as some other DVRs and they cost a lot more to purchase plus they consume a lot more power. So, as a first step, one needs to clearly specify the objectives in mind. Clearly defining the problem is always the best way to start. And never forget that old maxim: A Job Well Begun Is Already Half Done.

Well don't say you weren't warned by the experts on this forum not to buy that system. Honestly, why do people bother asking the Installers for their valuable opinions and then go right ahead and ignore them? Frankly, I'd be surprised if that system achieves any long-term goals. And if it doesn't, then you're back to square one again. The objective of this forum is not to penny-pinch every step of the way.

This strikes me as the Law of Diminishing Returns. If this is a cheap no-name PTZ, all this effort to resolve the 12VDC issue might well be the beginning of your problems. I hope the PTZ internals are substantially built PCBs; motors; fans; belts; with a brand name camera module. If they are not, you may be chasing down annoying little problems from now on - until individual parts of the unit begin to fail. If it is a substantially built PTZ then it is certainly worth the effort. But this gets me back to the question of 24-28VAC versus 12VDC. Most of the quality generic Chinese PTZ units now take almost any voltage offered by the Power Supplies mentioned. A generic PTZ that only takes 12VDC today, appears to be a sign that the manufacturer is not a serious contender.

I searched the archives and couldn't find a 2012 Pelco Pricelist. This is dated 12/01/2010 and "Effective November 4th 2011" which looks like it is the current pricelist. Here it is. A Retail Pricelist. All 267 Pages: http://www.peppm.org/Products/pelco/price.pdf

hardwired wrote: The last generic dome I installed (which is a good copy of a Spectra II) has a tiny gap for cable entry. A big spider got past that and onto the inside of the lower dome. I had to go up a ladder, take off the plexiglass dome and flick the blighter out. The 1.5" NPT threaded pipe on the top of the Back Box leads directly to a fairly insubstanial rubber 'cable guide' just above the PCB board. Certainly no deterent for bugs and spiders to enter. dustmop wrote: I have never seen "Sealtite rubber-coated flexible metal conduit" which sounds like a better solution than plain ol' galvanised metal flexible conduit. (Or even stainless) So the lowest point of the 4' pole will have to be sealed with expandable spray foam or a compression fitting which also looks like a good solution - like a large cable gland.

Thanks Dustmop for the details about the ‘sleeve’ fittings on the PP4348. It looks like a good general purpose parapet mount with greater flexibility than the 451. The PP4348 can also take an Esprit, unlike the 351/451 which are purpose built for the Spectras (plus DF5s and DF8s). I will go ahead with the PP451 because, as you point out, it has a greater reach. This would allow it to reach out and over the top of the building thus maximizing the downward view of the PTZ. The hurricane capability is welcome news too. I said earlier that 60mph winds are normal, but I think it has maxed out at around 80mph with golf ball sized hail stones. Recent weather smashed some vehicle windows and actually dented car bodies when a mini-tornado struck. And the last thing I would want to see is the Spectra crashing to the ground or dangling from its cables.. I have one IWM GY lying around. I ordered the IWM24-GY, but, of course, the IWM-GY arrived without the inbuilt transformer. I really didn’t need the 24, other than out of curiosity and perhaps having some redundancy in case the 24VAC power supply fails. (Probably better to buy a spare MCS Power Supply.) The distances are not too great, so I will simply run some 16AWG Carol up to the camera. Thanks again.

It isn't just the face shots so much as the body silhouettes. After a while, you can identify local hoods, crims, scumbags, gypsies, perps, and ne'er do wells by their outlines. It is also quite hard to get a good facial shot with a fixed camera unless you point it down a sidewalk or onto oncoming pedestrians. Lower cameras also evoke that lovely lump-in-the-throat squirm when they eyeball the enclosures pointing right at them. For the really close close-up face shots and number plate shots, I rely on the PTZ. Almost all of the regular neighbourhood punks make a 300' arc to avoid the cameras. (They pay their respects at a great distance by pointing out the location of the PTZ to their punk friends - but I can still easily make them out at 300'.) I achieved this psychological victory by placing close-up mugshots on nearby light poles. The photos and information about a crime tell everybody that the cameras are effective. The problem of new heroin addicts, though, never quite goes away. Junkies new to the area are typical 'heroes' and the heroin in their veins makes them believe they are indestructible. (the word 'heroin' is obviously derived from the word 'hero') I mount most of my cameras at about ten feet (3 metres) off the ground. I am currently working on mounting a new Spectra at about 25+ feet off the deck to get a panoramic shot over 270 to hopefully 360 degrees. For lighting, I mostly keep that low too; to avoid shadows. I use a combination of high lumen HID and compact flouros, though I am looking for some 10,000 lumens LED luminaires which are still rather expensive. The HIDs have a slow startup so they are not much good as "instant on lights". The same goes for the compact flouros. I use the HIDs when gangbangers try to get cosy in their pimped-out rides directly in front of my house. When they are still too stupid to get it - somehow thinking the lights are a free service - I use a PA Horn to inform them that my PTZ is videoing the needle they are currently sticking into their arm. At 130 decibels, "Hey bros, yeah you in the orange Chevy - yeah you - you wanna stick that needle in yer arm someplace else bro! Yo solid!" So far that last ditch method has worked without fail.