After hunkering down for a while you might find yourself buried alive under the amount of low voltage networking information.
While crawling and running in the trench you'll bump into fellow soldiers cat5e, fiber optic cable, security cameras. You'll also find tutorials, tips, installation aids and all kinds of cool networking stuff!
The commander and chief is Discount-Low-Voltage.com
Testing fiber optic cable can be intimidating if you've never done it before, but we've decided to open a fiber test kit and figure out how to measure db loss just for you.
Looks easy because it is. For more cool videos follow our YouTube Channel .
I get sucked into this discussion constantly and it always ends up being a long conversation that goes round and round and ends up going nowhere.
Our good buddy Ron with Ideal Industries discusses the differences of a qualifier vs certifier when the quality of your network cabling is in question.
Did you notice the standards chart did not include "Cat5 Big E" or "Cat5e 350mhz"? Did you find a standard for "Cat6E"? Those are probably topics that you'll have to educate your customer on.
Over the past 15 years we've sold all kinds of fiber products for all kinds of different projects but I think the most overlooked part about a fiber optic network installation might be the use of fiber optic mandrels for proper insertion loss testing.
Before we get into the mandrels themselves let's all get on the same page with "ZEROING" your fiber optic light source and power meter. Our good friend Professor Jim Powers with Optical Wavelength Laboratories gives us a great explanation on "ZEROING".
Thanks Professor Jim Powers, now let's get into the mandrel.
Your LED light source emits light over an area larger than the typical
multimode fiber core causing the low and high order modes to get excited. The
simplest way to calm your light source down is to tightly bend the
launch cable from your light source tester around a mandrel.
A fiber optic mandrel is a very inexpensive tool to help improve your fiber optic testing as the tight bends around the mandrel calm the light source down. Mandrels allow the use of your overfilled LED light source to properly certify 50 and 62.5 fiber links for high bit rates such as Gigabit Ethernet and 10 Gigabit Etherent.
These mandrels are not a "want to" or "don't want to" tool to use during testing. This is not 'Nam, there are rules, and according to TIA/EIA-568-B it specifies that attenuation (insertion loss) measurements of multimode fiber links for all applications be made using an overfilled light source, such as an LED with a mandrel-wrap mode filter on the transmit jumper. This enables certification of multimode links for Gigabit and 10 Gigibit. Also allows for existing 850/1300 LED light sources to test 50 and 62.5 links.
Now let's use our fiber mandrel for "ZEROING"!
Wrap the "transmit jumper" five times around the mandrel and attach it to the output port of your LED source. Then attach the other end of the jumper to your power meter and set your wavelength.
Set your reference to display "0 dB" indicating that the power measured at output of the transmit jumper has been recorded as the reference level for your insertion loss measurements. You have now completed the "One Jumper Method".
Now disconnect your transmit jumper from your power source but NOT from your light source. Attach a "receive jumper" to to your power meter. Mate together the "transmit jumper" and "receive jumper"
with a coupler. Make sure that the insertion loss is well under 0.75 dB
and that is the maximum allowed by TIA.
Now your ready to test the fiber link. Connect your light source to one end and your power meter to the other. Store results, print and rock and roll!
So long story short, a fiber mandrel is for modifying the distribution of a propagating fiber optic signal. You can order your fiber optic mandrel from DLV.
Almost forgot to show the mandrel in action, here a How-To video on DB loss.
Recently we had a contractor customer ask us, "What do you have for testing HDMI cables?" I then asked if he was making his own and if so I have a tester in mind but he had a couple of concerns. The first was that the end user provided the cable and wanted to make sure the cable worked properly since if there was a problem the customer may point the finger to him and not the cable. Second being that the cable was going to be pulled through a conduit and he wanted to make sure that the connectors were not damaged during the pull.
We recommended the Greenlee Data Shark HDMI Cable Tester.
The Greenlee DataShark HDMI cable tester can test for proper continuity before installation. Also a great diagnostic tool for checking cables already installed. The 1 piece design splits into 2 pieces a transmitter and receiver. The 9 LED readout is easy and very fast to read.
The contractor checked it out and for the price, it was well worth putting another tester into his collection.
