BNC Connectors - Screw-on vs Crimp-on

[jimbo 0]

I posted this message to the Alt.Security.Alarms Newsgroup in response to a question someone posted about whether crip-on connectors were worth the money.

 

Far too many dealers I see (and read about here and in other online forums) don't seem to appreciate the difference between the two types.

 

Anyways here's my original message:

 

Twist-on connectors as good as crimp-ons?!? Shame on you! Let's see what Charlie Pierce the guru of video has to say on this topic.

 

 

##################################################################

The following pulled from Charlies corner at http://www.ltctrainingcntr.com/

 

 

 

Dear Charlie,

 

I have a bet with my Service Manager that screw-on BNC connectors are not the best connectors that we could be using. He says that they are faster to install and so we should use them to cut costs. I say we should stick to the crimp on BNC. Who's right? Help! This is worth$10.00 to me.

 

Just sign me Cash Coming in California.

 

 

 

Dear Cash Coming,

 

You are right! Although the Screw-on BNC connectors appear to save you time in the field, they have too many factors against them to make them a true cost saving factor.

 

1. Screw-on connectors can and do vibrate loose, causing for sporadic video signal problems.

 

2. Screw-on connectors are not considered moisture tight and in actuality suck up moisture through the threaded base of the connector causing corrosion of the coaxial cable.

 

3. Most cases of connector problems that I have seen, that involve the Screw-on connectors are caused by improper installation of the connector and/or the use of a cheap connector.

 

4. These connectors cannot be used in any circumstance where; the cable may be in motion (pole to pole or pan/tilt installations); outside (to many humidity problems); or where the connector may be put on and taken off a piece of equipment often (field patch cords).

 

In the end, many manufacturers of cameras systems are starting to label the Screw-on BNC as an illegal connector due to the extensive problems found in the field. My best advise is that if yours is a long term company, stick to the three piece crimp on BNC connectors. At the end of the day, a good technician can install a three piece crimp on BNC connector in the same amount of or less time than a Screw-on connector.

 

 

end of article

 

#####################################################################

 

Personally we have been using the two piece connector from ICM Corp (http://www.icmcorp.net/F-ConnSeries.htm) for a number of years now.

 

These connectors are built like a battle ship and come in two pieces. A base that gets crimped on the cable and is sized to match the cable (rg59 vs rg6). A 2nd piece is threaded onto the crimped base to provid3 either a BNC or RCA connector. They also make F-connectors (F59) for those of you doing satellite or dtructured cable.

 

Their website kind of sucks as it doesn't show how the connectors go together but take my word they work really well. Call them and ask for some samples.

[rory 0]

I have Charlie Pierces Book, its outdated.

 

The biggest problem with twist ons is most people dont know how to put them on properly. Same can be said with crimp ons. Obviously any extreme conditions would require a good crimp on for sure.

[Thomas 0]

Speaking of books, any good recomendations for books on CCTV? I'm not going to be an installer, but it would help with troubleshooting.

[rory 0]

Pierces Installation book is actually good, just ignore the part about recorders, and some camera stuff is outdated also, but alot of other useful info.

[Thomas 0]

I'm reading Damjanovski's book right now, but it's a little dry.

[cctv_down_under 0]

A little DRY!!!!!!!!! thats an undertsatement, however it is indeed my bible!

[Cooperman 0]

Interesting that nobody mentioned solder connectors.

 

Installers hate them, because they take slightly longer to fit (and they cost more), but for most critical applications, the failure rate is so low, it's not even worth thinking about (especially if you use adhesive lined heat shrink sleeving as a strain relief).

 

I found the failure rate on screw ons ... frightening; and I stopped using crimps about fifteen years ago, simply because I was fed up with cleaners moving equipment on desks, and then having to go back and refit because of strained connections.

 

If you haven't tried soldering a BNC, 25 feet up the side of a building in a high wind, you simply haven't lived (never tried it in a hurricane though ).

 

I suppose one day I ought to get hold of a CCTV book and have a read; then at least I'll know where I've been going wrong all these years

[rory 0]

thats another thing, crimp ons come loose also. With a twist on anyone can simply screw it back on if it comes loose without the need of a crimping tool, new connector, and knowledge of crimping.

 

Where do you get soldered connectors from?

I tried pulling off the screw on connectors on my last job and none would pull off, they were screwed on so tight, so I think they will do just fine

 

I dont think you'd want to be on a ladder in a hurricane, I was on one in 35mph winds before the hurricane and that was hell trying to keep the ladder from blowing over and had to hold on to building tight myself !

[Cooperman 0]

No problem getting solder plugs this side of the pond Rory.

 

I have seen problems with screw on plugs, where the braiding begins to degrade over time, and you don't get a good 'screening' contact. They may be quick and easy, but I still won't use them.

 

Curious thought, but why do the most difficult and dangerous camera locations, only ever need a service call in high winds or pouring rain

Oh yea, I remember ... english weather!!

[qman 0]

If you haven't tried soldering a BNC, 25 feet up the side of a building in a high wind, you simply haven't lived (never tried it in a hurricane though ).

 

 

YOU GOT THAT RIGHT!!!!

 

 

I did it about 60FT up in the air, in the middle of a snowstrom about 2 years ago, while I still lived in NY.

[Cooperman 0]

I did it about 60FT up in the air, in the middle of a snowstrom about 2 years ago, while I still lived in NY.

 

I hope this is fitting BNC connectors that you're talking about

 

Funny, I thought it was only the Swiss that did that

[survtech 0]

I have Charlie Pierces Book, its outdated.

 

Pierces Installation book is actually good, just ignore the part about recorders, and some camera stuff is outdated also, but alot of other useful info.

 

[scorpion 0]

I do not seem to have failure problems whether I use crimp on, or twist on.

 

I seem to have more problems with the quality of the product. Some years back our distributor was sent a bad set of crimp ons. Talk about having multiple failures from multiple installs! That was hell in a hand basket. The dist sent me a new order overnighted, and no additional charges. Nice to see it when your dist stands behind your back to make you look good when chaos reigns!

 

I like the twist ons, but recently I received an order of 100 from a dist, and I thought they were plastic when I picked up one, and it did not have any weight to it. It did not seem to be a quality product, and I have yet to use them on an install out of fear of call backs.

[bpzle 0]

I only use compression! Let's fight about it!

[pikach 0]

I only use compression! Let's fight about it!

I used compresion on my last job, and I'm having some problems with it.

They are very hard to connect properly, and they dont work as good as crimp ons, only pro is that its tighter...

[hardwired 0]

Three-piece crimp on only, for us. Too many problems have shown up later with the other types to be comfortable with.

 

Installs 10+ years later are just fine with three piece connectors (the connectors, at least, the other hardware is a little iffy at that age!), others (two piece, twist on) have failed much more often.

 

On a service call recently, it took me a while to find my RG59 crimpers at the bottom of my toolbox, it's been RJ45's on CAT5e/6 for us almost exclusively for a while now...

[bpzle 0]

Compression takes a little practice. Mainly you have to be careful not to leave the center conductor too long. I usually eyeball it, but most guides say around 1/8"? It helps to have good tools. Cheap DataShark ones at Home Depot I've found to be the best. I've used others that are wayyyy more expensive like Paladin and don't care for them.

 

Also, I've run into crappy a brand of connectors one time and hated them. Pins kept falling out. Can't remember what brand they were...

 

I too hardly use coax anymore. UTP all the way now...

[bpzle 0]

Hey when you guys use CAT6e, do you use special and complicated CAT6e RJ45s? I've got some but man they're a PITA.

 

I've heard it only makes a difference for gigabit, but I've only had to pull for 10/100.

Edited February 23, 2010 by Guest

[pikach 0]

 

I too hardly use coax anymore. UTP all the way now...

some people claim that using cat5 and convert it to bnc tend to loose quality is it true?

Or its the same exact quality as coax rg59?

[bpzle 0]

With good baluns, I can't tell a difference.

Maybe Rory can with his vintage CRT monitors though...

[pikach 0]

With good baluns, I can't tell a difference.

Maybe Rory can with his vintage CRT monitors though...

Which baluns do you use?

[kensplace 0]

Muxlab did some research on baluns (they also sell baluns) and concluded

 

Nighttime Operation

When the CCTV Baluns are used in nighttime conditions it is found that the image

luminosity may not be as good as when coax cable is used. This is because the pair of

baluns introduce approximately 3dB of signal loss, resulting in a loss of picture

luminosity under very dark conditions. If this occurs, the solution is either to replace the

passive CCTV Balun at the receiver end by an active CCTV balun or to replace the cable

by coax.

 

http://www.muxlab.com/assets/files/application_guides/VE_CCTV_Balun.pdf

 

Analogue CRT monitors will enable you to see problems with a picture from analogue cameras easier than LCD style monitors, CCTV (analogue) was designed for CRT display, so you will get a better picture on one. They are bulky and expensive to run compared to modern flat screens, so many people prefer the newer style, for cosmetic purposes...

[survtech 0]

Hey when you guys use CAT6e, do you use special and complicated CAT6e RJ45s? I've got some but man they're a PITA.

We prefer the kind with IDC connectors on the balun, rather than having to install RJ45 connectors.

 

Analogue CRT monitors will enable you to see problems with a picture from analogue cameras easier than LCD style monitors, CCTV (analogue) was designed for CRT display, so you will get a better picture on one. They are bulky and expensive to run compared to modern flat screens, so many people prefer the newer style, for cosmetic purposes...

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.

[bpzle 0]

Which baluns do you use?

 

Can't remember... they're rebranded. I get them from one of my supplers. RJ45 in, BNC video, and 2.5mm for power. Pretty clean looking and they work pretty good.

[lengfeng203 0]

Hey when you guys use CAT6e, do you use special and complicated CAT6e RJ45s? I've got some but man they're a PITA.

We prefer the kind with IDC connectors on the balun, rather than having to install RJ45 connectors.

 

Analogue CRT monitors will enable you to see problems with a picture from analogue cameras easier than LCD style monitors, CCTV (analogue) was designed for CRT display, so you will get a better picture on one. They are bulky and expensive to run compared to modern flat screens, so many people prefer the newer style, for cosmetic purposes...

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.

 

I'm a manufacture of monitors,so,i can say something here.

 

1. 5 years ago all this is true, the lcd display effect is so bad,cant compare with the CRTs, But in recent years,lcd display tech developed so fast,especially after the LED Backlight tech is in use,actually,high-end lcd display products are not worse than the CRTs now, the display effect depends on what level of lcd are you chosing.

 

2. in the past,the CRT Tubes are mainly for TV use, nowadays,little people are buying CRT TVs,after loosing this part of market to LCD, most CRT Tube manufacture cant stand any more, most of them turn to LCD or bankrupted. So,most of manufactures of monitors has to turn to lcd.