cat5 cable tester

[b.a. marcus]

I promised I would post this. Any suggestions are welcome but I rarley
check bruceam@swbell.net; doggone spammers ran me off.
http://www.atomiccomputers.com/projects/cat5t_v2.0.0.html
e-mail webmaster@zebracomputers.net if you have any suggestions.
Also, see the PUT post I made.

Thanks
Bruce aka zebra

 

[Watson A.Name - "Watt Sun]

In article <921df43.0312291829.661dca3f@posting.google.com>,
bruceam@swbell.net mentioned...

I promised I would post this. Any suggestions are welcome but I rarley
check bruceam@swbell.net; doggone spammers ran me off.
http://www.atomiccomputers.com/projects/cat5t_v2.0.0.html
e-mail webmaster@zebracomputers.net if you have any suggestions.
Also, see the PUT post I made.

Thanks
Bruce aka zebra

I'm not trying to disparage the project, but this really doesn't test
cat5 cable. It tests for continuity, but not shorts, so you could
call it a half test(?) But its biggest drawback is that it cannot
detect split pairs. IMHO, if you use a piece of test equipment that
tells you that the device under test is okay, but you replace the DUT
and it cures the problem, then using that test equipment is worse than
not having it at all, because it misleads you and wastes your time.

At work, I do this testing daily. I used to get complaints that the
cabling in the walls, which is my responsibility, isn't working
properly. The tech from another site will tell me that the PC will
work on the network at 10Mb, but not at 100. So I drags out the Fluke
DSP-2000 (costs $5000) and test the cabling. And the cabling in the
wall passes the test okay.

But I test the patch cord between the wall and the PC and it tests
BAD. I tell this to the tech, and he says, "But I checked it with my
Byte Brothers tester, and it tests okay!" Yeah, I tell him, because
your POS tester doesn't detect split pairs, and when you assembled the
patch cord with your crimping tool, you got the wires transposed so
they are a split pair.

See, he has been using that patchcord for years on an old PC that's
only running at 10 Mb, so it works, but probably has a lotta bad
packets and errors. Now that he is using it on a PC with a 100Nb NIC,
it really has major problems with bad packets and errors. Back when
the dufus made the patch cord, he didn't realize that he was making
the cable wrong.

And adding insult to injury is that his POS tester won't tell him what
the problem is, so he's blaming the wall wiring or anything else
instead.

Anyway, after embarrassing a few techs by proving with my FLuke that
their cabling is bogus, I've finally got them to test the setup with a
different patch cable -- usually a store bought, aka not a homemade,
patch cord -- before they tell us the wall wiring is bad. And I've
asked the head honcho to stop the techs from wasting their time making
their patch cords, and use store bought ones, which are pretested.
Well, supposedly, but then that's a whole 'nother story. And I have
another coupla horror stories that occurred recently, but you will
probably have to see them on comp.dcom.cabling newsgroup, where this
post really belongs.

BTW, you can get a Siemon STM-8 tester which detects split pairs for a
couple hundred dollars. Or if you wanna waste time, build the
project, but it will probably cost more than the $50 that a cheap
tester costs.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[b.a. marcus]

I found a cheap tester at Fry's for around $30 dollars. The project
costs more in my time then it does parts. The project does test for
transposed wires and, yes, it is a continuity/polarity tester. Besides
the fact that a tech that transposes wires has to be an idiot. The
"shifted" or "transposed" pairs can be detected by the missing pulse.
The Decade counter resets on the 6th count instead of the 5th. The way
I see it, it's major drawback is that it doesn't test cable length or
short cicuits (which may be tested by other means). But I can darn
near guarantee that if this tester says the cable is "OK", then the
cable IS "OK". If you need an authoritative "Yes" answer, this is
pretty darn close. If I charged myself $50 dollars and hour to build
the tester, it wouldn't be worth my time. But I estimate the cost of
parts to be under $10. And all but one of the parts can be found in an
old POS radio.

A hammer needs a nail but it also needs a thumb and 4 fingers.
Thanx for your input.

Bruce

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a5af4505847a381989ace@news.dslextreme.com>...

In article <921df43.0312291829.661dca3f@posting.google.com>,
bruceam@swbell.net mentioned...
I promised I would post this. Any suggestions are welcome but I rarley
check bruceam@swbell.net; doggone spammers ran me off.
http://www.atomiccomputers.com/projects/cat5t_v2.0.0.html
e-mail webmaster@zebracomputers.net if you have any suggestions.
Also, see the PUT post I made.

Thanks
Bruce aka zebra

I'm not trying to disparage the project, but this really doesn't test
cat5 cable. It tests for continuity, but not shorts, so you could
call it a half test(?) But its biggest drawback is that it cannot
detect split pairs. IMHO, if you use a piece of test equipment that
tells you that the device under test is okay, but you replace the DUT
and it cures the problem, then using that test equipment is worse than
not having it at all, because it misleads you and wastes your time.

At work, I do this testing daily. I used to get complaints that the
cabling in the walls, which is my responsibility, isn't working
properly. The tech from another site will tell me that the PC will
work on the network at 10Mb, but not at 100. So I drags out the Fluke
DSP-2000 (costs $5000) and test the cabling. And the cabling in the
wall passes the test okay.

But I test the patch cord between the wall and the PC and it tests
BAD. I tell this to the tech, and he says, "But I checked it with my
Byte Brothers tester, and it tests okay!" Yeah, I tell him, because
your POS tester doesn't detect split pairs, and when you assembled the
patch cord with your crimping tool, you got the wires transposed so
they are a split pair.

See, he has been using that patchcord for years on an old PC that's
only running at 10 Mb, so it works, but probably has a lotta bad
packets and errors. Now that he is using it on a PC with a 100Nb NIC,
it really has major problems with bad packets and errors. Back when
the dufus made the patch cord, he didn't realize that he was making
the cable wrong.

And adding insult to injury is that his POS tester won't tell him what
the problem is, so he's blaming the wall wiring or anything else
instead.

Anyway, after embarrassing a few techs by proving with my FLuke that
their cabling is bogus, I've finally got them to test the setup with a
different patch cable -- usually a store bought, aka not a homemade,
patch cord -- before they tell us the wall wiring is bad. And I've
asked the head honcho to stop the techs from wasting their time making
their patch cords, and use store bought ones, which are pretested.
Well, supposedly, but then that's a whole 'nother story. And I have
another coupla horror stories that occurred recently, but you will
probably have to see them on comp.dcom.cabling newsgroup, where this
post really belongs.

BTW, you can get a Siemon STM-8 tester which detects split pairs for a
couple hundred dollars. Or if you wanna waste time, build the
project, but it will probably cost more than the $50 that a cheap
tester costs.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[b.a. marcus]

Yeah I messed up pretty bad on that circuit. It was a mistake I made
on the first tester I built. Pretty embarrassing.
Thanx for getting me to do some thinking Watson.

What do you think about the update..
http://www.atomiccomputers.com/projects/cat5t_v2.0.html

 

[Watson A.Name - "Watt Sun]

In article <921df43.0312301321.55c886fe@posting.google.com>,
bruceam@swbell.net mentioned...

I found a cheap tester at Fry's for around $30 dollars. The project
costs more in my time then it does parts. The project does test for
transposed wires and, yes, it is a continuity/polarity tester. Besides
the fact that a tech that transposes wires has to be an idiot. The

Unfortunatelyu there are contractors that hire idiots to install cat5.
Fortunately they get weeded out pretty quuickly, buit before they do,
they can make some serious errors. But yeah, you seldom run into this
problem.

"shifted" or "transposed" pairs can be detected by the missing pulse.
The Decade counter resets on the 6th count instead of the 5th. The way
I see it, it's major drawback is that it doesn't test cable length or
short cicuits (which may be tested by other means). But I can darn
near guarantee that if this tester says the cable is "OK", then the
cable IS "OK". If you need an authoritative "Yes" answer, this is
pretty darn close.

In most cases of a cat5 cabling problem where the cabling was
previously working, the Fluke tells me it's an open wire. Usually
this is at either the wall jack or patch panel, and simply repunching
down both ends takes care of the problem. For years I got by without
the Fluke (or any tester, for that matter), just by doing this simple
procedure. If that didn't fix the problem, then I'd replace the
cable.

So I never needed a tester. And the nice thing about this is that it
costs nothing. And it never gives you a false answer.

If I charged myself $50 dollars and hour to build
the tester, it wouldn't be worth my time. But I estimate the cost of
parts to be under $10. And all but one of the parts can be found in an
old POS radio.

A hammer needs a nail but it also needs a thumb and 4 fingers.
Thanx for your input.

Bruce

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a5af4505847a381989ace@news.dslextreme.com>...
In article <921df43.0312291829.661dca3f@posting.google.com>,
bruceam@swbell.net mentioned...
I promised I would post this. Any suggestions are welcome but I rarley
check bruceam@swbell.net; doggone spammers ran me off.
http://www.atomiccomputers.com/projects/cat5t_v2.0.0.html
e-mail webmaster@zebracomputers.net if you have any suggestions.
Also, see the PUT post I made.

Thanks
Bruce aka zebra

I'm not trying to disparage the project, but this really doesn't test
cat5 cable. It tests for continuity, but not shorts, so you could
call it a half test(?) But its biggest drawback is that it cannot
detect split pairs. IMHO, if you use a piece of test equipment that
tells you that the device under test is okay, but you replace the DUT
and it cures the problem, then using that test equipment is worse than
not having it at all, because it misleads you and wastes your time.

At work, I do this testing daily. I used to get complaints that the
cabling in the walls, which is my responsibility, isn't working
properly. The tech from another site will tell me that the PC will
work on the network at 10Mb, but not at 100. So I drags out the Fluke
DSP-2000 (costs $5000) and test the cabling. And the cabling in the
wall passes the test okay.

But I test the patch cord between the wall and the PC and it tests
BAD. I tell this to the tech, and he says, "But I checked it with my
Byte Brothers tester, and it tests okay!" Yeah, I tell him, because
your POS tester doesn't detect split pairs, and when you assembled the
patch cord with your crimping tool, you got the wires transposed so
they are a split pair.

See, he has been using that patchcord for years on an old PC that's
only running at 10 Mb, so it works, but probably has a lotta bad
packets and errors. Now that he is using it on a PC with a 100Nb NIC,
it really has major problems with bad packets and errors. Back when
the dufus made the patch cord, he didn't realize that he was making
the cable wrong.

And adding insult to injury is that his POS tester won't tell him what
the problem is, so he's blaming the wall wiring or anything else
instead.

Anyway, after embarrassing a few techs by proving with my FLuke that
their cabling is bogus, I've finally got them to test the setup with a
different patch cable -- usually a store bought, aka not a homemade,
patch cord -- before they tell us the wall wiring is bad. And I've
asked the head honcho to stop the techs from wasting their time making
their patch cords, and use store bought ones, which are pretested.
Well, supposedly, but then that's a whole 'nother story. And I have
another coupla horror stories that occurred recently, but you will
probably have to see them on comp.dcom.cabling newsgroup, where this
post really belongs.

BTW, you can get a Siemon STM-8 tester which detects split pairs for a
couple hundred dollars. Or if you wanna waste time, build the
project, but it will probably cost more than the $50 that a cheap
tester costs.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Watson A.Name - "Watt Sun]

In article <921df43.0312302154.1be158af@posting.google.com>,
bruceam@swbell.net mentioned...

Yeah I messed up pretty bad on that circuit. It was a mistake I made
on the first tester I built. Pretty embarrassing.
Thanx for getting me to do some thinking Watson.

What do you think about the update..
http://www.atomiccomputers.com/projects/cat5t_v2.0.html

It makes more sense now. Needs a battery and on/off switch. Nothing
says what the battery V is, but I'd assume 9V.

The link to the All About site shows a SCS, nothing to do with the PUT
or an oscillator.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[b.a. marcus]

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a5c3d0db23ed5fa989adc@news.dslextreme.com>...

In article <921df43.0312301321.55c886fe@posting.google.com>,
bruceam@swbell.net mentioned...
I found a cheap tester at Fry's for around $30 dollars. The project
costs more in my time then it does parts. The project does test for
transposed wires and, yes, it is a continuity/polarity tester. Besides
the fact that a tech that transposes wires has to be an idiot. The

Unfortunatelyu there are contractors that hire idiots to install cat5.
....

9Volts. Or 12 if you want to carry a transformer around too...
That'll make for some bright LED's.

Once I saw the mistake I threw it together real quick and forgot about
the voltage.

SCS... hmmm, musta been in a rush on that one too.

 

[b.a. marcus]

bruceam@swbell.net (b.a. marcus) wrote in message news:<921df43.0312310828.6dd9c222@posting.google.com>...

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a5c3d0db23ed5fa989adc@news.dslextreme.com>...
In article <921df43.0312301321.55c886fe@posting.google.com>,
bruceam@swbell.net mentioned...
I found a cheap tester at Fry's for around $30 dollars. The project
costs more in my time then it does parts. The project does test for
transposed wires and, yes, it is a continuity/polarity tester. Besides
the fact that a tech that transposes wires has to be an idiot. The

Unfortunatelyu there are contractors that hire idiots to install cat5.
...

9Volts. Or 12 if you want to carry a transformer around too...
That'll make for some bright LED's.

Once I saw the mistake I threw it together real quick and forgot about
the voltage.

SCS... hmmm, musta been in a rush on that one too.

I think x555 is the best way to go for the oscillator After all. The
PUT is sensitive to changes in voltage and quits oscillating when the
battery gets low. The only way to solve the problem is to add a
voltage regulator which complicates the circuit as much as a x555
does.

I have to say that I have not found a better cable tester on the web
than mine. I guess thats a matter of opinion though and like Watson
said, "Everybody has one."

Nevertheless, I have not had an opportunity to sit down and hash out
the figures on the PUT (see my PUT post). Actually I found a circuit
that has a "better", I mean more simple, oscillator. And I can't
believe I never thought of it.
http://www.atomiccomputers.com/projects/sutton-001.html
I have actually driven the decade counter in this manner when I was
testing the decade counter with a 555 and an LED to indicate pulses.

Well, it's a learning experience. Started working on this thing back
in August 03. That's when I built the first tester. Never built an
electronics project before that.

Watson, I think this post fits better here than it does in cabling
now. You were right about the 555 but not about this post. just
kidding.