For anyone curious about the reason of the mandrel, at least from my humble knowledge: each channel in multimode is transmitted at a slightly different angle, so when the receiver gets it, it can figure out which channel it is because of the angle. The higher the angle, the "higher order" of mode it is. The mandrel is a tightly wrapped coil that causes higher orders(higher angles) of light to lose their angle and transmit more directly. It does not affect lower orders of channels. This is mainly done for testing purposes, if you don't use a mandrel, the tester might accidentally report a higher dB loss than it really is. Have a good day :)

@perrooceaniko2005

5 жыл бұрын

this is correct .. the higher modes are eliminated or attenuated strongly after the mandrel . Only the main modes are of interest. By the way, heavy losses show a so small piece of cable …

@somethingsomethingsomethingdar

5 жыл бұрын

Best explanation I have heard and it makes sense

@HOLIGHTFiberOptic

3 жыл бұрын

Wow

All good Mercy..... Show and Tell done well. Appreciate the "asking for the order", (perhaps a little smoother).....but overall a great job on a complex subject. Nice work.

Good show! Just a little correction... when you write the result as a loss do not write it as a negative number; it should be positive because "loss" takes care of the negative, else it becomes negative of a negative which is "gain". Loss of 3.00 dB and not loss of -3.00 dB

@perrooceaniko2005

5 жыл бұрын

very rightly said !! or you may say, in a complicated math way, a gain of -3db !!!!!!!! :-) :-) :-)

Before testing would you not zero out the meter with both transmit and receive patch chords connected to one another with a some sort of coupler?

I have been getting different results with positive and negative values, when I am doing insertion loss testing. One result will be .026dB while another will be -0.15dB. What does that signify?

Great Video Mercy. Can you recommend a chart or graph that will give installers a Rough guide to what Acceptable losses we can expect to find out in the field. Tks. Trevor.

@dusanveselka3240

7 жыл бұрын

The accepted maximum db loss is 1.5 for multimode and thats what you should expect (your loss will be higher with smaller fibre, lets say 50/125 than lets say 62.5/125).

Hi Mercy, Great tutorial. Question: if you want to measure total loss to include customer patch cords at both ends, do you still need to use the jumper with the mandrel after setting reference? Meaning plugging in customer patch cords directly to the light source and meter. Thanks!

Another question, what is the mandrels purpose?

COULD TELL ME HOW IS THAT THING CALLED WITH THE CORD WRAP??

NICE VIDEO

So is -0.14db acceptable for a 400 ft run? Was my first splice... I was supervised but unaided ;P

so touching for an excellent video

Mercy, I need to do a check on a piece of bare fiber prior to putting the connector on the fiber. are there adapters that let you non destructive grab onto a single fiber strand on both ends and check for loss. Thanks in advance.

@mumbles1justin

8 жыл бұрын

+Chris Howells as soon as a tip is replaced, removed etc from fiber your loss readings will change. there are bare fiber adapters on the market if you need to take TDR or OTDR readings that "grab fiber". But bare fiber adapters aren't very useful with OLTS readings.

when is insertion loss in negative and when is it in positive?

What testers do you have for "single mode", & are there any testers available for use with smart phones?

@shamshulqamar3807

8 жыл бұрын

+Mercy Salinas we have face some problem in LS/PM test results of single mode like this 1310nm _____0. 65db 1550nm_____0. 8169db cable length 0. 161km sir what is the solution

I work on aircraft fitted with fiber optic lines and have a couple of questions. I have sma connectors (threaded coupler with a brass barrel that slides into a female hole in the box), are all these types of connectors the same size? Also, does your test kit (light source and meter) come ready to use with these sma connectors or do I need a adapter? Thanks for any help.

@2WheelsAs1

9 жыл бұрын

***** Thanks for the info!

I have 1490 nm -19.18 dbm is good or bad ?

thanks bro

Very informative

Is there a chart you have that I can go by to see what the db should be at for certain lengths? Is it best to have more or less insertion loss? I'm very new to fiber cabling.

@quacktony

9 жыл бұрын

***** So I'm testing a 36ft LC to LC multimode. Its showing -18db. Is that good? Power source is 850nm.

@quacktony

9 жыл бұрын

***** I might be doing something wrong. I'm going to reset everything.

@quacktony

9 жыл бұрын

***** I love the reply though LOL.

@quacktony

9 жыл бұрын

***** Zeroed out my meter, powered both the source and meter on and let it sit for 5 minutes, saved current reading of -18.43dbm, I disconnect the meter and hook up the 36ft cable, now it reads -0.65db.

@quacktony

9 жыл бұрын

***** Thanks for your help in figuring out my new toy!!!

I need of the fiber optic cable cable power management

Ok thanks. i already found it , didnt know how is called it

Please make video cd testing for optic fiber and cd full from al so

why throw out a patch cord without cleaning it or scoping it to see if that's where your loss is coming from?

Great!

is there other name for fibre tester?

@mumbles1justin

8 жыл бұрын

+Tayo Ahmed OLTS

nice vodeo

Good

"black magic" haha isn't that the truth! Great straight forward video, thanks!

aiyoo salli

tusant cable net NEPAL

it cost more than $50 that kit ;-)

how you take the reference without connecting the two patchcord with zero db connector ????????????? you r using only one patchcord for reference hhhh