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Crimping tool, odd review

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  Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-28 15:37 +0100
    Re: Crimping tool, odd review Poblano <8minutes@450F.com> - 2025-05-28 10:20 -0700
      Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-29 11:49 +0100
    Re: Crimping tool, odd review Andy Burns <usenet@andyburns.uk> - 2025-05-28 19:20 +0100
      Re: Crimping tool, odd review Lawrence D'Oliveiro <ldo@nz.invalid> - 2025-05-29 04:17 +0000
    Re: Crimping tool, odd review Chris Green <cl@isbd.net> - 2025-05-28 19:29 +0100
    Re: Crimping tool, odd review Theo <theom+news@chiark.greenend.org.uk> - 2025-05-29 09:33 +0100
      Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-29 12:04 +0100
        Re: Crimping tool, odd review Theo <theom+news@chiark.greenend.org.uk> - 2025-05-29 17:34 +0100
          Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-29 18:22 +0100
            Re: Crimping tool, odd review Theo <theom+news@chiark.greenend.org.uk> - 2025-05-29 19:48 +0100
              Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-29 23:02 +0100
                Re: Crimping tool, odd review Paul <nospam@needed.invalid> - 2025-05-30 06:05 -0400
                  Re: Crimping tool, odd review Dan Purgert <dan@djph.net> - 2025-05-30 14:10 +0000
                Re: Crimping tool, odd review Jasen Betts <usenet@revmaps.no-ip.org> - 2025-07-01 09:10 +0000
                  Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-07-01 18:46 +0100
                    Re: Crimping tool, odd review "Carlos E.R." <robin_listas@es.invalid> - 2025-07-01 20:58 +0200
              Re: Crimping tool, odd review Dan Purgert <dan@djph.net> - 2025-05-29 22:55 +0000
                Re: Crimping tool, odd review Java Jive <java@evij.com.invalid> - 2025-05-30 11:56 +0100
              Re: Crimping tool, odd review "Carlos E. R." <robin_listas@es.invalid> - 2025-05-30 16:20 +0200
    Re: Crimping tool, odd review Dan Purgert <dan@djph.net> - 2025-05-29 11:21 +0000
      Re: Crimping tool, odd review Chris Green <cl@isbd.net> - 2025-05-29 12:38 +0100
      Re: Crimping tool, odd review "Carlos E. R." <robin_listas@es.invalid> - 2025-05-29 13:54 +0200

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#81582 — Crimping tool, odd review

Please excuse the Linux/Windows cross-post, this is a general question 
about networking gear.

I'm thinking of buying a CAT-Crimper, and was looking at this model ...

 
<https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B0DLNV7KDB>

... for which the reviews are mostly very good, but I was a little taken 
aback by this one ...

 
<https://www.amazon.co.uk/product-reviews/B0DLNV7KDB/ref=cm_cr_getr_d_paging_btm_next_3?pageNumber=3>

Michael Howe
2.0 out of 5 stars Not suitable for gigabit WiFi.
Reviewed in the United Kingdom on 17 March 2025
Model: CHZHHYF Verified Purchase
Product worked as intended, but I have gigabit internet and all the 
cables I made are limited to 100mbps.

... I'm thinking, surely the cable and connector combination should be 
what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
used?  Perhaps he means that the connectors supplied are not fully 
populated, and so reduced to 100Mbps?

What are others' thoughts?

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

[toc] | [next] | [standalone]

#81584

On 5/28/25 07:37, Java Jive wrote:
> Please excuse the Linux/Windows cross-post, this is a general question 
> about networking gear.
> 
> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
> 
> 
> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/ 
> dp/B0DLNV7KDB>
> 
> ... for which the reviews are mostly very good, but I was a little taken 
> aback by this one ...
> 
> 
> <https://www.amazon.co.uk/product-reviews/B0DLNV7KDB/ 
> ref=cm_cr_getr_d_paging_btm_next_3?pageNumber=3>

Amazon needs me to sign in before I'm allowed to see it.
No.

> Michael Howe
> 2.0 out of 5 stars Not suitable for gigabit WiFi.
> Reviewed in the United Kingdom on 17 March 2025
> Model: CHZHHYF Verified Purchase
> Product worked as intended, but I have gigabit internet and all the 
> cables I made are limited to 100mbps.
> 
> ... I'm thinking, surely the cable and connector combination should be 
> what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
> used?  Perhaps he means that the connectors supplied are not fully 
> populated, and so reduced to 100Mbps?
> 
> What are others' thoughts?

Michael Howe wasn't much help.

Gary might have something useful.
https://www.amazon.co.uk/gp/customer-reviews/R1MJCVUNADEURX/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B0DLNV7KDB

" ...it cut everything flush but the tool doesn't compress fully 
resulting in the gold pins not being forced into the sheath of the 
individual data wires. This means all looks fine but the cable is not 
acknowledged and won't send data."

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#81590

On 2025-05-28 18:20, Poblano wrote:
> On 5/28/25 07:37, Java Jive wrote:
>> Please excuse the Linux/Windows cross-post, this is a general question 
>> about networking gear.
>>
>> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
>>
>>
>> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/ dp/B0DLNV7KDB>
>>
>> ... for which the reviews are mostly very good, but I was a little 
>> taken aback by this one ...
>>
>>
>> <https://www.amazon.co.uk/product-reviews/B0DLNV7KDB/ 
>> ref=cm_cr_getr_d_paging_btm_next_3?pageNumber=3>
> 
> Amazon needs me to sign in before I'm allowed to see it.
> No.

Yes, some of us here from different countries have encountered that sort 
of problem before, it's ridiculous.

>> Michael Howe
>> 2.0 out of 5 stars Not suitable for gigabit WiFi.
>> Reviewed in the United Kingdom on 17 March 2025
>> Model: CHZHHYF Verified Purchase
>> Product worked as intended, but I have gigabit internet and all the 
>> cables I made are limited to 100mbps.
>>
>> ... I'm thinking, surely the cable and connector combination should be 
>> what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
>> used?  Perhaps he means that the connectors supplied are not fully 
>> populated, and so reduced to 100Mbps?
>>
>> What are others' thoughts?
> 
> Michael Howe wasn't much help.
> 
> Gary might have something useful.
> https://www.amazon.co.uk/gp/customer-reviews/R1MJCVUNADEURX/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B0DLNV7KDB
> 
> " ...it cut everything flush but the tool doesn't compress fully 
> resulting in the gold pins not being forced into the sheath of the 
> individual data wires. This means all looks fine but the cable is not 
> acknowledged and won't send data."

Yes, I saw that review as well, but Michael Howe's raised the alarming 
possibility, that hadn't previously occurred to me, that the tool may 
only be suitable for making Fast Ethernet, 100Mbps, connections  - 
perhaps because it wouldn't crimp all the pairs in Cat5e/6 cables  - 
but nevertheless was being sold as suitable for Gigabit Ethernet, 
1000Mbps, connections.*

However, the general consensus seems to be that the difficulties with 
more modern designations of cable are that they have somewhat thicker 
strands and won't fit easily into at least some, quite possibly all, of 
the plugs supplied in the kits, hence people getting sub-standard 
results.  Some have even suggested throwing the plugs from the kits away 
and buying better quality ones separately.

*  I jumped upon this particularly because 10-15 years ago, not long 
after the Gigabit standard became available, I was in the market for a 
Gigabit switch, and *NEARLY ALL* the so-called 'Gigabit' switches 
advertised on eBay were in fact only Fast Ethernet; a few were even just 
Ethernet, 10Mbps!  I got so fed up I spent quite a while reporting them 
all in an effort to make looking through the listings a little more 
manageable.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

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#81585

Java Jive wrote:

> ... I'm thinking, surely the cable and connector combination should be 
> what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
> used?  Perhaps he means that the connectors supplied are not fully 
> populated, and so reduced to 100Mbps?
> 
> What are others' thoughts?

As long as you can get hold of the "through style" plugs in future 
should be ok, they are a little easier to see that you've got the pairs 
inserted in proper sequence.

I can only think that the reviewer didn't get the wiring correct, but if 
he thinks he's wiring "gigabit wifi", who knows?

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#81588

On Wed, 28 May 2025 19:20:05 +0100, Andy Burns wrote:

> ... but if he thinks he's wiring "gigabit wifi", who knows?

Wi-fi has to go through wires at some point. If the wires can’t cope with 
gigabit rates, then your wi-fi won’t either.

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#81586

Java Jive <java@evij.com.invalid> wrote:
> Please excuse the Linux/Windows cross-post, this is a general question 
> about networking gear.
> 
> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
> 
> 
> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B0DLNV7KDB>
> 
> ... for which the reviews are mostly very good, but I was a little taken 
> aback by this one ...
> 
> 
> <https://www.amazon.co.uk/product-reviews/B0DLNV7KDB/ref=cm_cr_getr_d_paging_btm_next_3?pageNumber=3> 
> 
> 
> Michael Howe
> 2.0 out of 5 stars Not suitable for gigabit WiFi.
> Reviewed in the United Kingdom on 17 March 2025
> Model: CHZHHYF Verified Purchase
> Product worked as intended, but I have gigabit internet and all the 
> cables I made are limited to 100mbps.
> 
> ... I'm thinking, surely the cable and connector combination should be 
> what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
> used?  Perhaps he means that the connectors supplied are not fully 
> populated, and so reduced to 100Mbps?
> 
> What are others' thoughts?
> 
Yes, it does very much sound as if the reviewer was misconfiguring his
cables doesn't it!  You have to make pretty bad (but correctly
configured) cables to stop them working at gigabit speeds. I've made
quite a few quite long ones and as long as all the wires are correctly
connected they 'just work' at 1000Mb/s.

-- 
Chris Green
·

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#81589

In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
> Please excuse the Linux/Windows cross-post, this is a general question 
> about networking gear.
> 
> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
> 
>  
> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B0DLNV7KDB>
> 
> ... for which the reviews are mostly very good, but I was a little taken 
> aback by this one ...

I bought that one. Well, one of the many lookalike listings of what's
presumably the same Chinese product - I can't find the exact listing but it
looks identical.  It was advertised as a cat6 kit.

It's ok, but I had a lot of difficulty getting cat6 solid core outdoor
cables to feed through it.  It seems there's two problems.  In the middle of
the cable is a cross-shaped structural plastic filler (keeps the pairs more
separated).  First problem is that doesn't fit into the rear of the RJ45
plugs they supplied very well.  One of my cat6s is double wrapped and gel
filled - I concluded that I need to strip off the first wrapping to have any
chance of getting it into the plug, but most of them I've just used the
wires for strain relief which isn't great.

Second problem is that I could only fit 7 wires into the plug before running
out of space. Seems like the insulation is slightly thicker and that doesn't
leave enough space for the last wire.  What I ended up doing was stripping
all the wires to bare copper and feeding the stripped wires through.  Then
going through each wire in turn and pulling it so the insulation pulled
through the connector.  By pulling each one a little at a time I could
eventually work it to get all 8 wires through.

At least I could do that - I have a stash of older non-passthrough
connectors in both regular and 'load bar' type and there was no chance I
could get the wires in position with those.  I killed at least a dozen
trying.

When I finally got everything in position and crimped it, they all worked
first time, which was nice.

> Michael Howe
> 2.0 out of 5 stars Not suitable for gigabit WiFi.
> Reviewed in the United Kingdom on 17 March 2025
> Model: CHZHHYF Verified Purchase
> Product worked as intended, but I have gigabit internet and all the 
> cables I made are limited to 100mbps.
> 
> ... I'm thinking, surely the cable and connector combination should be 
> what limits the result to Fast Ethernet, 100Mbps, not what crimper was 
> used?  Perhaps he means that the connectors supplied are not fully 
> populated, and so reduced to 100Mbps?

Probably he didn't make the terminations correctly and so was down a pair,
which would have resulted in dropping back to 100Mbps.  The kit doesn't come
with a tester to confirm the connections are good (some other kits do; I
already had one).

> What are others' thoughts?

Use patch panel sockets with proper punchdown terminals and a punchdown tool
(Krone or 110, depending on what you sockets need), avoid using RJ45 plugs
at all costs, and buy ready made patch leads where you can.  Punchdown is so
so much easier.

Theo

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#81591

Thanks for *ALL* the replies, all of which I've read, but mostly they 
don't require an individual response ...

On 2025-05-29 09:33, Theo wrote:
>
> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>
>> Please excuse the Linux/Windows cross-post, this is a general question
>> about networking gear.
>>
>> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
>>
>>   
>> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B0DLNV7KDB>
>>
>> ... for which the reviews are mostly very good, but I was a little taken
>> aback by this one ...
> 
> I bought that one. Well, one of the many lookalike listings of what's
> presumably the same Chinese product - I can't find the exact listing but it
> looks identical.  It was advertised as a cat6 kit.
> 
> It's ok, but I had a lot of difficulty getting cat6 solid core outdoor
> cables to feed through it.  It seems there's two problems.  In the middle of
> the cable is a cross-shaped structural plastic filler (keeps the pairs more
> separated).  First problem is that doesn't fit into the rear of the RJ45
> plugs they supplied very well.  One of my cat6s is double wrapped and gel
> filled - I concluded that I need to strip off the first wrapping to have any
> chance of getting it into the plug, but most of them I've just used the
> wires for strain relief which isn't great.

Videos for another I examined show the demonstrator cutting out the 
central filler:

https://www.amazon.co.uk/Solsop-Kit-Ethernet-Crimper-Crimping/dp/B09WR31VK2

> Second problem is that I could only fit 7 wires into the plug before running
> out of space. Seems like the insulation is slightly thicker and that doesn't
> leave enough space for the last wire.  What I ended up doing was stripping
> all the wires to bare copper and feeding the stripped wires through.  Then
> going through each wire in turn and pulling it so the insulation pulled
> through the connector.  By pulling each one a little at a time I could
> eventually work it to get all 8 wires through.

Yes, since posting my OP I've come across quite a few similar tales. 
With almost all of the crimpers, choosing to view critical reviews will 
bring up a raft of them  -  it's a negatively biased sample to be sure, 
so you have to make allowances for that, but I find it useful to do this 
to get a sense of "What's the worst that can happen?!"

As you suggest, and as suggested by other reviewers, there seems to be a 
problem getting more recent CAT standard cables to fit into the 
connectors supplied in the kits, because the individual strands are 
somewhat thicker than perhaps the connectors were designed for.

> At least I could do that - I have a stash of older non-passthrough
> connectors in both regular and 'load bar' type and there was no chance I
> could get the wires in position with those.  I killed at least a dozen
> trying.
> 
> When I finally got everything in position and crimped it, they all worked
> first time, which was nice.

That's encouraging for someone like myself with ageing and less steady 
hands.

>> Michael Howe
>> 2.0 out of 5 stars Not suitable for gigabit WiFi.
>> Reviewed in the United Kingdom on 17 March 2025
>> Model: CHZHHYF Verified Purchase
>> Product worked as intended, but I have gigabit internet and all the
>> cables I made are limited to 100mbps.
>>
>> ... I'm thinking, surely the cable and connector combination should be
>> what limits the result to Fast Ethernet, 100Mbps, not what crimper was
>> used?  Perhaps he means that the connectors supplied are not fully
>> populated, and so reduced to 100Mbps?
> 
> Probably he didn't make the terminations correctly and so was down a pair,
> which would have resulted in dropping back to 100Mbps.  The kit doesn't come
> with a tester to confirm the connections are good (some other kits do; I
> already had one).

Many variants of the kits have testers, including one from the same 
supplier, so probably wisest for me to go for one of those:

https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B08L4CHL7V

>> What are others' thoughts?
> 
> Use patch panel sockets with proper punchdown terminals and a punchdown tool
> (Krone or 110, depending on what you sockets need), avoid using RJ45 plugs
> at all costs, and buy ready made patch leads where you can.  Punchdown is so
> so much easier.
Noted.

Thanks as always, Theo.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

[toc] | [prev] | [next] | [standalone]

#81595

In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
> Thanks for *ALL* the replies, all of which I've read, but mostly they 
> don't require an individual response ...
> 
> On 2025-05-29 09:33, Theo wrote:
> >
> > In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
> >>
> >> Please excuse the Linux/Windows cross-post, this is a general question
> >> about networking gear.
> >>
> >> I'm thinking of buying a CAT-Crimper, and was looking at this model ...
> >>
> >>   
> >> <https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B0DLNV7KDB>
> >>
> >> ... for which the reviews are mostly very good, but I was a little taken
> >> aback by this one ...
> > 
> > I bought that one. Well, one of the many lookalike listings of what's
> > presumably the same Chinese product - I can't find the exact listing but it
> > looks identical.  It was advertised as a cat6 kit.
> > 
> > It's ok, but I had a lot of difficulty getting cat6 solid core outdoor
> > cables to feed through it.  It seems there's two problems.  In the middle of
> > the cable is a cross-shaped structural plastic filler (keeps the pairs more
> > separated).  First problem is that doesn't fit into the rear of the RJ45
> > plugs they supplied very well.  One of my cat6s is double wrapped and gel
> > filled - I concluded that I need to strip off the first wrapping to have any
> > chance of getting it into the plug, but most of them I've just used the
> > wires for strain relief which isn't great.
> 
> Videos for another I examined show the demonstrator cutting out the 
> central filler:
> 
> https://www.amazon.co.uk/Solsop-Kit-Ethernet-Crimper-Crimping/dp/B09WR31VK2

Yes, you cut the filler down to where you've stripped off the outer sheath. 
But you need to poke the whole outer sheath including filler into the back
of the RJ45 for strain relief, and it was impossible to do that with the
supplied plugs.  Different RJ45s have different cable entry gaps at the
back, and it seems that different variations of cat5e/cat6 indoor/outdoor
have different thicknesses of gap.  These are probably ok for regular cat5e
and maybe indoor cat6 but didn't fit outdoor cat6.

> > Second problem is that I could only fit 7 wires into the plug before running
> > out of space. Seems like the insulation is slightly thicker and that doesn't
> > leave enough space for the last wire.  What I ended up doing was stripping
> > all the wires to bare copper and feeding the stripped wires through.  Then
> > going through each wire in turn and pulling it so the insulation pulled
> > through the connector.  By pulling each one a little at a time I could
> > eventually work it to get all 8 wires through.
> 
> Yes, since posting my OP I've come across quite a few similar tales. 
> With almost all of the crimpers, choosing to view critical reviews will 
> bring up a raft of them  -  it's a negatively biased sample to be sure, 
> so you have to make allowances for that, but I find it useful to do this 
> to get a sense of "What's the worst that can happen?!"
> 
> As you suggest, and as suggested by other reviewers, there seems to be a 
> problem getting more recent CAT standard cables to fit into the 
> connectors supplied in the kits, because the individual strands are 
> somewhat thicker than perhaps the connectors were designed for.

It seems like you need to buy RJ45 connectors to match the cable
construction you have, but they aren't widely available to take different
thicknesses.

In a pro install you'd never be putting plugs on 'structured wiring', it
would all be punchdown sockets and patch leads.  But there's certain use
cases where you need to wire a structured cable directly into a device. 
Although even in structured wiring there can be a socket on the ceiling for
an access point with a short patch cable, rather than hanging the cable out
of the ceiling and into the access point.

> Many variants of the kits have testers, including one from the same 
> supplier, so probably wisest for me to go for one of those:
> 
> https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B08L4CHL7V

Either that or an RJ45 socket at each end and a multimeter.  But the tester
makes it quicker.

(can't speak for that tester - you need to test for open circuits, shorts
and mis-wired pairs and I can't tell if it does that.  In particular if it's
structured wiring you need to be able to test from one end because you can't
see both ends at the same time as the cable runs through the building -
unless you can run a long patch cable back to the start)

Theo

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#81596

On 2025-05-29 17:34, Theo wrote:
>
> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>
>> As you suggest, and as suggested by other reviewers, there seems to be a
>> problem getting more recent CAT standard cables to fit into the
>> connectors supplied in the kits, because the individual strands are
>> somewhat thicker than perhaps the connectors were designed for.
> 
> It seems like you need to buy RJ45 connectors to match the cable
> construction you have, but they aren't widely available to take different
> thicknesses.

Yes, that's the impression I get.

> In a pro install you'd never be putting plugs on 'structured wiring', it
> would all be punchdown sockets and patch leads.  But there's certain use
> cases where you need to wire a structured cable directly into a device.
> Although even in structured wiring there can be a socket on the ceiling for
> an access point with a short patch cable, rather than hanging the cable out
> of the ceiling and into the access point.

Understood.

>> Many variants of the kits have testers, including one from the same
>> supplier, so probably wisest for me to go for one of those:
>>
>> https://www.amazon.co.uk/Through-Ethernet-Crimping-Connectors-Stripper/dp/B08L4CHL7V
> 
> Either that or an RJ45 socket at each end and a multimeter.  But the tester
> makes it quicker.
> 
> (can't speak for that tester - you need to test for open circuits, shorts
> and mis-wired pairs and I can't tell if it does that.  In particular if it's
> structured wiring you need to be able to test from one end because you can't
> see both ends at the same time as the cable runs through the building -
> unless you can run a long patch cable back to the start)
As I understand, the two halves of those testers slide apart and you can 
put one half at each end to perform the test.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

[toc] | [prev] | [next] | [standalone]

#81597

In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
> On 2025-05-29 17:34, Theo wrote:
> > Either that or an RJ45 socket at each end and a multimeter.  But the tester
> > makes it quicker.
> > 
> > (can't speak for that tester - you need to test for open circuits, shorts
> > and mis-wired pairs and I can't tell if it does that.  In particular if it's
> > structured wiring you need to be able to test from one end because you can't
> > see both ends at the same time as the cable runs through the building -
> > unless you can run a long patch cable back to the start)
> As I understand, the two halves of those testers slide apart and you can 
> put one half at each end to perform the test.

Do you need to see both ends to run the test, or is one sufficient?

I saw a video showing that a green light on each part scans down the numbers
1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
at both ends, or if a fault is only shown at the end that detects it.

(eg if you had open circuit at one end and a short at the other, what would
it tell you?)

Theo

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#81598

On 2025-05-29 19:48, Theo wrote:
>
> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>> 
>> As I understand, the two halves of those testers slide apart and you can
>> put one half at each end to perform the test.
> 
> Do you need to see both ends to run the test, or is one sufficient?
> 
> I saw a video showing that a green light on each part scans down the numbers
> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
> at both ends, or if a fault is only shown at the end that detects it.
> 
> (eg if you had open circuit at one end and a short at the other, what would
> it tell you?)

Well, I've not used one, so I'm guessing based solely on electronic 
logic.  Hopefully, if I'm wrong, someone will correct me.

1)  If the cable was miswired by crossing two cables, then I'd expect 
the lights at one end, most probably the remote end, to light in the 
wrong order.

2)  If you have a short at one end, I'd expect two lights to be on at 
the same time at least at that end, probably at both.

3)  If you have an open circuit, I'd expect the corresponding light at 
one end or the other to fail to light.

But let's see if anyone can confirm what actually happens based on 
actual experience.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

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#81600

On Thu, 5/29/2025 6:02 PM, Java Jive wrote:
> On 2025-05-29 19:48, Theo wrote:
>>
>> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>>
>>> As I understand, the two halves of those testers slide apart and you can
>>> put one half at each end to perform the test.
>>
>> Do you need to see both ends to run the test, or is one sufficient?
>>
>> I saw a video showing that a green light on each part scans down the numbers
>> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
>> at both ends, or if a fault is only shown at the end that detects it.
>>
>> (eg if you had open circuit at one end and a short at the other, what would
>> it tell you?)
> 
> Well, I've not used one, so I'm guessing based solely on electronic logic.  Hopefully, if I'm wrong, someone will correct me.
> 
> 1)  If the cable was miswired by crossing two cables, then I'd expect the lights at one end, most probably the remote end, to light in the wrong order.
> 
> 2)  If you have a short at one end, I'd expect two lights to be on at the same time at least at that end, probably at both.
> 
> 3)  If you have an open circuit, I'd expect the corresponding light at one end or the other to fail to light.
> 
> But let's see if anyone can confirm what actually happens based on actual experience.
> 

A GbE chip, has MDI/MDIX and the two ends of the cable
automatically negotiate the highest rate they can manage.
I presume in this case, that starts with selecting
GbE full duplex 1gbit mode and trying to make that work.

If the four pairs do not operate, for whatever reason,
the negotiation will eventually drop to 100BT and the
two pairs on 1,2,3,6 . I don't think there is a reason
for the GbE end to move to 10BT 1,2,3,6, unless some kind
of response from the other end, indicates that is all the
hardware can manage.

A second kind of diagnostic, is a Marvell Ethernet Chip,
has a TDR (Time Domain Reflectometer), it shoots a pulse
down each pair. If the end is shorted or open, that causes
a reflection off the spot, and the Marvell
logic block measures the pulse polarity and arrival time
(possibly to the nearest 1 nanosecond). If your cable
was shorted in the middle and not at the crimp, the TDR
method tells you roughly where to look for crushing damage.

I'm not aware of any NIC PHY having the ability to work
at the "I've got eight wires level" and figure out
what is connected to what, as a means of vetting home made
cables with the wires shoved in the wrong holes (like
an attempt to make a "rolled" cable). For that matter,
the MDI/MDIX on the Gbe, is even capable of dealing
with "straight" wiring pattern or "rolled" wiring
pattern. Either cable works. Whereas with 100BT NICs
as endpoints, if you use the wrong cable, it fails
to function, you switch cable types (remove that yellow
cable from the broadband modem box), and the interface
starts to work.

The GbE NIC then, is the magical beast, up to the point of
the user has mis-wired and put the wires in the wrong holes,
and the wrong-ness happens to not be in the MDI/MDIX feature
set :-)

The PCI Express used on computer motherboards, is similarly
whizzy at this kind of stuff. If one of the wires on a
PCI Express interface isn't working, the interface
can restore enough functionality (reduced bandwidth)
for the equipment to carry on. PCI express can even handle
an endian problem, such that if the diff pairs are flipped
on bus order... it still works. I don't know what they
were smoking when they came up with all of this, but it must
drive the implementers nuts to support it all. You're running
at very high speed, and you have all these modes, and negotiations
to do. (The negotiation was even broken, in one generation, and
some video cards needed their VBIOS flashed up, to jam the bus
into the lower speed mode. The industry is better at checking
for compliance now.)

   Paul

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#81602

On 2025-05-30, Paul wrote:
> On Thu, 5/29/2025 6:02 PM, Java Jive wrote:
>> On 2025-05-29 19:48, Theo wrote:
>>>
>>> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>>>
>>>> As I understand, the two halves of those testers slide apart and you can
>>>> put one half at each end to perform the test.
>>>
>>> Do you need to see both ends to run the test, or is one sufficient?
>>>
>>> I saw a video showing that a green light on each part scans down the numbers
>>> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
>>> at both ends, or if a fault is only shown at the end that detects it.
>>>
>>> (eg if you had open circuit at one end and a short at the other, what would
>>> it tell you?)
>> 
>> Well, I've not used one, so I'm guessing based solely on electronic logic.  Hopefully, if I'm wrong, someone will correct me.
>> 
>> 1)  If the cable was miswired by crossing two cables, then I'd expect the lights at one end, most probably the remote end, to light in the wrong order.
>> 
>> 2)  If you have a short at one end, I'd expect two lights to be on at the same time at least at that end, probably at both.
>> 
>> 3)  If you have an open circuit, I'd expect the corresponding light at one end or the other to fail to light.
>> 
>> But let's see if anyone can confirm what actually happens based on actual experience.
>> 
>
> A GbE chip, has MDI/MDIX and the two ends of the cable
> automatically negotiate the highest rate they can manage.
> I presume in this case, that starts with selecting
> GbE full duplex 1gbit mode and trying to make that work.

Note that MDI-X is more of a (fast-)ethernet thing, and not really used
by gbit-ethernet. This is because, whereas (fast-)ethernet specifies
pins 1,2 as TX, and 3,6 as RX, gbit-ethernet utilizes all four pairs
bidirectionally.

Least in 25 years, I've never seen a link come up at gbit with a
crossover-cable.  There *might* be something about this in the gbit
specs, but I don't have them to hand anymore :( .

>
> If the four pairs do not operate, for whatever reason,
> the negotiation will eventually drop to 100BT and the
> two pairs on 1,2,3,6 . I don't think there is a reason
> for the GbE end to move to 10BT 1,2,3,6, unless some kind
> of response from the other end, indicates that is all the
> hardware can manage.

If the cable is sufficiently damaged, it might fail down to 10 before
dropping link.

>
> A second kind of diagnostic, is a Marvell Ethernet Chip,
> has a TDR (Time Domain Reflectometer), it shoots a pulse
> down each pair. If the end is shorted or open, that causes
> a reflection off the spot, and the Marvell
> logic block measures the pulse polarity and arrival time
> (possibly to the nearest 1 nanosecond). If your cable
> was shorted in the middle and not at the crimp, the TDR
> method tells you roughly where to look for crushing damage.
>
> I'm not aware of any NIC PHY having the ability to work
> at the "I've got eight wires level" and figure out
> what is connected to what, as a means of vetting home made
> cables with the wires shoved in the wrong holes (like
> an attempt to make a "rolled" cable). For that matter,
> the MDI/MDIX on the Gbe, is even capable of dealing
> with "straight" wiring pattern or "rolled" wiring
> pattern. Either cable works. Whereas with 100BT NICs
> as endpoints, if you use the wrong cable, it fails
> to function, you switch cable types (remove that yellow
> cable from the broadband modem box), and the interface
> starts to work.

If by "rolled", you mean swapping pin1 for pin8 (and likewise all the
rest), you are correct in that no NIC can figure that mess out.  

If you mean swapping between 568-A/B on the same cable (pairs 2 and 3 -
white-green/green and white-orange/orange -- i.e. "creating a crossover
cable"), gbit NICs will likely downgrade to fast ethernet due to the
garbled bi-directional pairs.

In order to not accidentally creating crossover cables, regardless of
whether both ends are 8p8c connectors, or if only one end is -- pick
568-A or -B and stick with it everywhere (I learned it as 568-B first,
so that's my go-to).  When you do the 8p8c, the clip needs to be DOWN
(so you're looking at the bottom, with the gold contacts). Being
Right-Handed, I hold the 8p8c connector in the right hand and the cable
in my left.  This ends up setting the orientation as "farthest pin from
me" is pin 1. 

This means that when I untwist the conductors and orient them for
insertion into the 8p8c, their orientation will be: 

  (farthest) white-orange
  orange
  white-green
  blue
  white-blue
  green
  white-brown
  (closest) brown

If you're left-handed, everything just gets inverted (that is, the
farthest pin from you is pin 8).

  (farthest) brown
  white-brown
  green
  white-blue
  blue
  white-green
  orange
  (closest) white-orange

Then it's just a matter of trimming the conductors to the appropriate
length, getting everything into the appropriate pin slots, and the
outer sheathing to where that little strain-relief bit is (the
triangular / rectangular bit that deforms when you crimp down on the
8p8c).  This is sometimes far more difficult than it sounds :)

In the event of cat6 (indoor or outdoor cable), when you're cutting out
that stupid spacer on the inside, give it a decent yank so it stretches
out a little bit (about 1/8" or 3mm is enough), then cut it off. When
you cut it off, it'll retract back to its original length (or
thereabouts), and give you a little bit of an easier time of getting the
outer sheathing into the 8p8c connector.

HTH :)

-- 
|_|O|_| 
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1  E067 6D65 70E5 4CE7 2860

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#81656

On 2025-05-29, Java Jive <java@evij.com.invalid> wrote:
> On 2025-05-29 19:48, Theo wrote:
>>
>> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>> 
>>> As I understand, the two halves of those testers slide apart and you can
>>> put one half at each end to perform the test.
>> 
>> Do you need to see both ends to run the test, or is one sufficient?
>> 
>> I saw a video showing that a green light on each part scans down the numbers
>> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
>> at both ends, or if a fault is only shown at the end that detects it.
>> 
>> (eg if you had open circuit at one end and a short at the other, what would
>> it tell you?)
>
> Well, I've not used one, so I'm guessing based solely on electronic 
> logic.  Hopefully, if I'm wrong, someone will correct me.

The scanning light testers give indication only that ther terminals
are connected in the correctr order,  that catch more than 99% of all
miswired connectors.... because usually you get one pair right.

> 1)  If the cable was miswired by crossing two cables, then I'd expect 
> the lights at one end, most probably the remote end, to light in the 
> wrong order.

Exactly that happens.  If the numbers "555" and "4017" mean anything to
you you can probably guess how these devices are built.

> 2)  If you have a short at one end, I'd expect two lights to be on at 
> the same time at least at that end, probably at both.

Both ends show both lights at reduced brightness

> 3)  If you have an open circuit, I'd expect the corresponding light at 
> one end or the other to fail to light.

Yeah the unpowered end gets no light, the powered end gets a slightly
brighter light. (assuming that the receiver is attached at the other
end)



-- 
 Jasen.
 🇺🇦 Слава Україні

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#81657

On 2025-07-01 10:10, Jasen Betts wrote:
>
> On 2025-05-29, Java Jive <java@evij.com.invalid> wrote:
>>
>> On 2025-05-29 19:48, Theo wrote:
>>>
>>> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>>>
>>>> As I understand, the two halves of those testers slide apart and you can
>>>> put one half at each end to perform the test.
>>>
>>> Do you need to see both ends to run the test, or is one sufficient?
>>>
>>> I saw a video showing that a green light on each part scans down the numbers
>>> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
>>> at both ends, or if a fault is only shown at the end that detects it.
>>>
>>> (eg if you had open circuit at one end and a short at the other, what would
>>> it tell you?)
>>
>> Well, I've not used one, so I'm guessing based solely on electronic
>> logic.  Hopefully, if I'm wrong, someone will correct me.
> 
> The scanning light testers give indication only that ther terminals
> are connected in the correctr order,  that catch more than 99% of all
> miswired connectors.... because usually you get one pair right.
> 
>> 1)  If the cable was miswired by crossing two cables, then I'd expect
>> the lights at one end, most probably the remote end, to light in the
>> wrong order.
> 
> Exactly that happens.  If the numbers "555" and "4017" mean anything to
> you you can probably guess how these devices are built.
> 
>> 2)  If you have a short at one end, I'd expect two lights to be on at
>> the same time at least at that end, probably at both.
> 
> Both ends show both lights at reduced brightness
> 
>> 3)  If you have an open circuit, I'd expect the corresponding light at
>> one end or the other to fail to light.
> 
> Yeah the unpowered end gets no light, the powered end gets a slightly
> brighter light. (assuming that the receiver is attached at the other
> end)

Thanks for the detailed explanation.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

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#81658

On 2025-07-01 19:46, Java Jive wrote:
> On 2025-07-01 10:10, Jasen Betts wrote:
>>
>> On 2025-05-29, Java Jive <java@evij.com.invalid> wrote:
>>>
>>> On 2025-05-29 19:48, Theo wrote:
>>>>
>>>> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>>>>>
>>>>> As I understand, the two halves of those testers slide apart and 
>>>>> you can
>>>>> put one half at each end to perform the test.
>>>>
>>>> Do you need to see both ends to run the test, or is one sufficient?
>>>>
>>>> I saw a video showing that a green light on each part scans down the 
>>>> numbers
>>>> 1 to 8 then 'G'.  But I'm not sure if you are testing that the 
>>>> lights match
>>>> at both ends, or if a fault is only shown at the end that detects it.
>>>>
>>>> (eg if you had open circuit at one end and a short at the other, 
>>>> what would
>>>> it tell you?)
>>>
>>> Well, I've not used one, so I'm guessing based solely on electronic
>>> logic.  Hopefully, if I'm wrong, someone will correct me.
>>
>> The scanning light testers give indication only that ther terminals
>> are connected in the correctr order,  that catch more than 99% of all
>> miswired connectors.... because usually you get one pair right.
>>
>>> 1)  If the cable was miswired by crossing two cables, then I'd expect
>>> the lights at one end, most probably the remote end, to light in the
>>> wrong order.
>>
>> Exactly that happens.  If the numbers "555" and "4017" mean anything to
>> you you can probably guess how these devices are built.
>>
>>> 2)  If you have a short at one end, I'd expect two lights to be on at
>>> the same time at least at that end, probably at both.
>>
>> Both ends show both lights at reduced brightness
>>
>>> 3)  If you have an open circuit, I'd expect the corresponding light at
>>> one end or the other to fail to light.
>>
>> Yeah the unpowered end gets no light, the powered end gets a slightly
>> brighter light. (assuming that the receiver is attached at the other
>> end)
> 
> Thanks for the detailed explanation.

Yeah, I crimp very few cables, so I have not seen some of the failure 
modes Jasen describes, and the booklet doesn't say either.

-- 
Cheers, Carlos.

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#81599

On 2025-05-29, Theo wrote:
> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>> On 2025-05-29 17:34, Theo wrote:
>> > Either that or an RJ45 socket at each end and a multimeter.  But the tester
>> > makes it quicker.
>> > 
>> > (can't speak for that tester - you need to test for open circuits, shorts
>> > and mis-wired pairs and I can't tell if it does that.  In particular if it's
>> > structured wiring you need to be able to test from one end because you can't
>> > see both ends at the same time as the cable runs through the building -
>> > unless you can run a long patch cable back to the start)
>> As I understand, the two halves of those testers slide apart and you can 
>> put one half at each end to perform the test.
>
> Do you need to see both ends to run the test, or is one sufficient?
>
> I saw a video showing that a green light on each part scans down the numbers
> 1 to 8 then 'G'.  But I'm not sure if you are testing that the lights match
> at both ends, or if a fault is only shown at the end that detects it.
>
> (eg if you had open circuit at one end and a short at the other, what would
> it tell you?)

Yes, you need both ends in order to complete the test circuit; but you
can look at them independently. Verification is basically that on the
REMOTE end (smaller unit without the battery), the LEDs count in the
correct order (1,2,...8,G).  LEDs on the main end (the one with the
battery) -- at least in the testers I have here -- are just wired in
parallel to the conductor under test, and don't actually provide any
insight into the conductor state.

Note that these LED testers will only find *electrical* faults (crossed
conductors, missed terminations, etc.); but the testers can't confirm if
the run is actually "good". For example, if it got crushed in a bend
somewhere, electrically the cable is OK, but the excessive bend radius
may cause problems at gbit speeds.

-- 
|_|O|_| 
|_|_|O| Github: https://github.com/dpurgert
|O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1  E067 6D65 70E5 4CE7 2860

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#81601

On 2025-05-29 23:55, Dan Purgert wrote:
> 
> Yes, you need both ends in order to complete the test circuit; but you
> can look at them independently. Verification is basically that on the
> REMOTE end (smaller unit without the battery), the LEDs count in the
> correct order (1,2,...8,G).  LEDs on the main end (the one with the
> battery) -- at least in the testers I have here -- are just wired in
> parallel to the conductor under test, and don't actually provide any
> insight into the conductor state.
> 
> Note that these LED testers will only find *electrical* faults (crossed
> conductors, missed terminations, etc.); but the testers can't confirm if
> the run is actually "good". For example, if it got crushed in a bend
> somewhere, electrically the cable is OK, but the excessive bend radius
> may cause problems at gbit speeds.

Understood, thanks for the explanation.

-- 

Fake news kills!

I may be contacted via the contact address given on my website: 
www.macfh.co.uk

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#81603

On 2025-05-29 20:48, Theo wrote:
> In uk.comp.os.linux Java Jive <java@evij.com.invalid> wrote:
>> On 2025-05-29 17:34, Theo wrote:
>>> Either that or an RJ45 socket at each end and a multimeter.  But the tester
>>> makes it quicker.
>>>
>>> (can't speak for that tester - you need to test for open circuits, shorts
>>> and mis-wired pairs and I can't tell if it does that.  In particular if it's
>>> structured wiring you need to be able to test from one end because you can't
>>> see both ends at the same time as the cable runs through the building -
>>> unless you can run a long patch cable back to the start)
>> As I understand, the two halves of those testers slide apart and you can
>> put one half at each end to perform the test.
> 
> Do you need to see both ends to run the test, or is one sufficient?

You need to watch both ends, but doesn't need to be at the same time. 
Yes, a fault can happen that is only detected at one end. Like the 
lights going in a different order.


-- 
Cheers,
        Carlos E.R.

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