RE: CAT 5 testers

["Keith Doxey" <ukha@xxxxxxx>]

A good tester will show shorts between conductors and crossed pairs etc.

Your method is OK as a basic check but suppose there is a short on the
Oragne pair 1&2. You put your probe on 1 on the first cable which is
looped
back on the second, you put the other probe on 1 on the second cable. Tests
OK. Move to pin 2. Tests OK. Cable wouldnt work because of Short 1-2. To
test properly with a meter you need to go

A1 - B1 Test for continuinty B2,B3,B4,B5,B6,B7,B8 Test for open
A2 - B2 Test for continuinty B3,B4,B5,B6,B7,B8 Test for open
A3 - B3 Test for continuinty B4,B5,B6,B7,B8 Test for open
A4 - B4 Test for continuinty B5,B6,B7,B8 Test for open
A5 - B5 Test for continuinty B6,B7,B8 Test for open
A6 - B6 Test for continuinty B7,B8 Test for open
A7 - B7 Test for continuinty B8 Test for open
A8 - B8

Only then do you know that all pins are straight and not open circuit.

At work I have a cable tester that can also do Co-ax, 9D, 15HD (VGA), 25D,
CENTRONICS. The cable doesnt have to have the same plugs on each end. It
has
two rows of LEDs and a button to step through the first row. Any
interconnected pins light the corresponding LED's. For example, a straight
9D-9D will light 1-1,2-2,3-3,4-4,5-5,6-6,7-7,8-8,9-9.

Where a cable tester is most useful is when you pick up an unknown lead
with
say a 9D on each end and you dont know whether it is a crossover or
straight
RS232, fully or minimal wired. Plug it in and you find 2-2,3-3,5-5 (minimal
straight) or 2-3,3-2,5-5 (minimal crossover). Saves a LOT of headaches.

Unfortunately testers like that are VERY expensive for an individual to buy
buy in the commercial world can pay for themselves hundreds of times over.
It is also usefull if you need to make an identical lead up, just plug the
original in, write down the pinout, make and test your lead. Saves having
to
disassemble connectors or perform a multitues of tests line the RJ45
example
above.

Keith

> -----Original Message-----
> From: Campbell [mailto:c.macd@xxxxxxx]
> Sent: 08 June 2001 23:23
> To: ukha_d@xxxxxxx
> Subject: Re: [ukha_d] CAT 5 testers
>
>
> Forgive my ignorance, but can someone simply explain the working of
the
> testers... I tend to test two lines at once by putting a patch
> cable at one
> end linking the two sockets and at the patch panel use two cables
> to a spare
> double socket, then simplty use a multimeter to check continuity..
Will a
> tester check losses etc on the cable, or just make life easier.
>
> Campbell
> ----- Original Message -----
> From: "Steve Gordon" <steve@xxxxxxx>
> To: <ukha_d@xxxxxxx>
> Sent: Thursday, June 07, 2001 1:08 PM
> Subject: RE: [ukha_d] CAT 5 testers
>
>
> > Graham,
> >
> > Thanks for the offer, unfortunately it's something that I will
need from
> > time to time so I may as well shell out for one.
> >
> > Thanks anyway.
> >
> > Steve
> > -----Original Message-----
> > From: Graham Howe [mailto:graham@xxxxxxx]
> > Sent: 07 June 2001 09:30
> > To: ukha_d@xxxxxxx
> > Subject: RE: [ukha_d] CAT 5 testers
> >
> >
> > I can lend you a set if you are round this way some time.
> >
> > Graham
> >
> > > -----Original Message-----
> > > From: Steve Gordon [mailto:steve@xxxxxxx]
> > > Sent: 07 June 2001 07:32
> > > To: Ukha_D@Yahoogroups. Com
> > > Subject: [ukha_d] CAT 5 testers
> > >
> > >
> > > Do Maplin sell CAT 5 testers, anyone?
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
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> > >
> > >
> > >
> > >
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>
>
>
>
>
>
>
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>




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http://www.automatedhome.co.uk
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____________________________________
Automated Home UK
http://www.automatedhome.co.uk
____________________________________

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/