CAT5e/6 connector/termination alternatives...

[Don Y]

On 10/3/2020 12:50 PM, Tom Del Rosso wrote:

It might be useful to test whatever method being considered by
retrofitting it onto the board of an 8-port gigabit switch. For $30 you
could test 8 methods for data errors.

My switch already gives me statistics on types of packets, errors, etc.
It also gives me information on the quality of the power delivered
to each PD. So, I can check for \"lossy\" connections at the PD
in \"real time\" (useful so I can ensure proper operation \"over time\"
instead of just \"at installation\").

 

[Jeff Liebermann]

On Sun, 4 Oct 2020 10:50:52 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

On 10/2/2020 10:34 PM, Jeff Liebermann wrote:
The smallest connector I know of are \"closed bottom pin sockets\".
https://www.te.com/usa-en/product-50863-4.html
https://www.te.com/usa-en/product-5050863-6.html

These look to just be a plane hollow cylinder -- no \"spring tines\"
(like you would find on a machined pin IC socket) to cling to the
\"mating\" conductor.

These have a spring inside. See PDF at:
<https://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Customer+Drawing%7F50863%7FZ4%7Fpdf%7FEnglish%7FENG_CD_50863_Z4.pdf%7F50863-4>
Hint: If the mating pin covers a range of diameters, such as 28 to 22
AWG in this socket, it has a spring inside.

More for #24 AWG to choose from:
<https://www.te.com/usa-en/search.html?q=pin%2Bsocket&n=130468&d=646048&type=products&samples=N&inStoreWithoutPL=false&instock=N>

You haven\'t said anything about the high cost.

From my (uneducated) observations, it appears that the way connectors
grab wires has a fair bit of thought involved. I\'d rather trust to
an ME (or Materials Scientist?) to sort that out, properly, than to
hope an /ad hoc/ approach will work scaled to production quantities.

Well, there should be something in the TE online catalog with a proper
signature in the title block of the drawing. I won\'t claim to be an
ME (materialistic engineer) but I have had some experience using those
connectors inside marine radios (xtal sockets and board interconnects)
and in applications somewhat beyond the imagination of the ME\'s.

Incidentally, I picked a gold plated pin socket because I thought it
looked cool and might get your attention. In reality, you want
something galvanically compatible with the copper CAT5 wire. Methinks
brass or tin would be best.

Perhaps if tapered pins were affixed to the ends of the wires to
ensure a more reliable fit...?

Before you invest time and money in such an abomination, it might be
useful if you first determine if you have a problem worth solving.
We\'re not talking about the retention force of a single wire in socket
connection here. We\'re talking about 8 such connections at the same
time. But if you believe insufficient retention force to be a
problem, please note that a simple cable clamp or hot melt glue blob
on the jacket, will act as a suitable stress reliever. Or, if you
really want more retention force, perhaps a longer version of the same
pin socket.

God: \"Noah?\"
Noah: \"Yes, Lord?\"
God: \"How long can you tread water?\"

Forever, with only 20 inches of rain last year:
<https://www.slvwd.com/sites/g/files/vyhlif1176/f/uploads/rainfall_13060_highway9_march-30-2020.pdf>

After a few similar discussions with various patriarchs, God became
tired of losing the arguments and stopped talking directly to mere
mortals.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Cydrome Leader]

Don Y <blockedofcourse@foo.invalid> wrote:

On 10/1/2020 9:55 PM, Jasen Betts wrote:
On 2020-10-01, Don Y <blockedofcourse@foo.invalid> wrote:
I\'m currently using punchdown blocks to terminate network cables
on my devices. But, they are considerably larger (volumetric)
than I\'d like. Coupled with the bend radius of the cables,
it requires a larger enclosure volume than I\'d like (I\'m aiming
for really small devices -- on the order of a couple of cubic
inches).

I\'d ruled out the more traditional 8P8C\'s as they\'re even more
bulky (and require additional labor to install).

Are there other connector/termination options that might be
leaner?

Do you have any bandwidth requirements?

I need to run 100Mb/Gbe over the link. But, I don\'t need to be able to
\"unmate\" the connection (which tends to be a requirement for \"typical\"
network connections).

I\'m currently looking at designing a custom connector along the lines
of the IDCs used for ribbon cable. But, I\'d like to avoid those tooling
charges and reliance on a single supplier.

what\'s wrong with the availalble IDC terminations?

Aside from 8P8C plugs, I don\'t see any IDC connectors/terminations that
are suited for the \"4 discrete pairs\" that you encounter in a CAT5/6
cable. I imagine you can repurpose a connector for that sort of
application but can\'t imagine it being a reliable undertaking
(installer errors, etc.) given that these aren\'t really just \"8
generic conductors\"

What I\'d like to see is 8 closely spaced holes/tubes/channels into
which the individual conductors could be inserted. Then, a \"cinching\"
mechanism to pierce their insulation and physically secure them to
the board.

Maybe scavenge the 110 IDC terminals off the back of an old 19\" rackmount
110 to RJ45 panel? They were soldered onto a PCB with the jacks the solder
onto the same board.

I\'ve never seen those solder mount 110 terminals in a catalog, but
somebody made or makes them. Lever lock terminals are pretty awful to work
with, and I don\'t see any that will piece the insulation. If you respect
the twists of the pairs, they\'re good to gigabit with no problem.

 

[Cydrome Leader]

Don Y <blockedofcourse@foo.invalid> wrote:

On 10/2/2020 8:54 PM, Grant Taylor wrote:
On 10/2/20 8:49 PM, Don Y wrote:
What I\'d like to see is 8 closely spaced holes/tubes/channels into
which the individual conductors could be inserted. Then, a \"cinching\"
mechanism to pierce their insulation and physically secure them to
the board.

What about the screw terminals that are common in alarm systems and PLCs.

I had considered the \"spring loaded\" sort of connections that you\'d encounter
(in a grossly overlarge implementation) for speaker connections. E.g.,
the Nest thermostat\'s field connections are of this form -- though as
INDIVIDUAL connections (I\'d prefer \"align set of conductors, depress
spring release, insert conductors, release spring\"). But, I\'m not sure
this would be a reliable connection.

One of the issues is that the connection is unlikely to be made
\"at a bench\" but, rather, atop a ladder, wandering around a mezzanine,
in the bowels of a piece of industrial equipment, etc. So, you want
it to be as simple and fool-proof as possible: insert wires (in some
particular order), then \"secure\" (crimp?)

(This is why I\'d suggested individual tubes/channels for each
conductor so the installer only has to get each conductor aligned
with appropriate channel and then \"drive it home\" -- while moving
on to the next conductor.)

There\'s another system called Krone which is like 110 but no impact
involved. A special tool with little scissors was needed. It looks like
the standard impact too, but more european. They were suitable for
ethernet and were sort of the \"cadillac\" for mass termination of
telecom/data wiring, at least 20 years ago. 110 terminations were way
harder to get right ever time vs. the krone stuff.

 

[whit3rd]

On Thursday, October 1, 2020 at 3:56:00 PM UTC-7, Don Y wrote:

I\'m currently using punchdown blocks to terminate network cables
on my devices. But, they are considerably larger (volumetric)
than I\'d like. Coupled with the bend radius of the cables,
it requires a larger enclosure volume than I\'d like (I\'m aiming
for really small devices -- on the order of a couple of cubic
inches).

I\'d ruled out the more traditional 8P8C\'s as they\'re even more
bulky (and require additional labor to install).

Are there other connector/termination options that might be
leaner?

It just hit me; a two-lump solution would be to put a powered USB port
at the terminus of your Ethernet, and use a limp USB A/ USB micro-B cable
to go to the device; that gives you an awkward bit of standard Etherhose-wire
for the long run, and a final few feet of limp cable to a tiny (volumetric)
device socket. This is one commercial item of the right sort:

<https://www.inavateonthenet.net/products/article/airtame-launches-poe-to-usb-adapter>

Then your onsite wiring would just be a choice of standard cable for length and color... and plugging
multi-sourced connectors together. Performance, though, would be USB-1 or USB-2 speeds with
that micro-B connection.

 

[Don Y]

On 11/6/2020 2:51 AM, whit3rd wrote:

On Thursday, October 1, 2020 at 3:56:00 PM UTC-7, Don Y wrote:
I\'m currently using punchdown blocks to terminate network cables
on my devices. But, they are considerably larger (volumetric)
than I\'d like. Coupled with the bend radius of the cables,
it requires a larger enclosure volume than I\'d like (I\'m aiming
for really small devices -- on the order of a couple of cubic
inches).

I\'d ruled out the more traditional 8P8C\'s as they\'re even more
bulky (and require additional labor to install).

Are there other connector/termination options that might be
leaner?

It just hit me; a two-lump solution would be to put a powered USB port
at the terminus of your Ethernet, and use a limp USB A/ USB micro-B cable
to go to the device; that gives you an awkward bit of standard Etherhose-wire
for the long run, and a final few feet of limp cable to a tiny (volumetric)
device socket. This is one commercial item of the right sort:

Then your onsite wiring would just be a choice of standard cable for length and color... and plugging
multi-sourced connectors together. Performance, though, would be USB-1 or USB-2 speeds with
that micro-B connection.

Clever approach -- but it\'s even bulkier than the punchdown blocks/service
loop! I am struggling to keep my devices REALLY small -- a few cubic inches
(and that to hold processor, RAM, PoE + some magic, I/O, etc.)

[And I\'m not sure I could get the b/w needed out of a USB connection]

I considered putting an 8P8C jack on the boards but that requires connectors
to be affixed to the ends of the cables \"on site\" (and often in tediously
inaccessible locations). Plus, introduces the bulk of the connector and
its mate as well as \"fixing\" the direction that the cable enters the board
(there may not be space for a service loop \"in that direction\" and hard
bends in the cable are discouraged)

This is very frustrating! I spend a disproportionate amount of time dealing
with mechanical issues (connectors, packaging, etc.). Things are considerably
easier when you\'re designing something to sit in a desktop/benchtop *box*! :<