CAT5e/6 connector/termination alternatives...

[Don Y]

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?

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.

 

[Jeff Liebermann]

On Thu, 1 Oct 2020 15:55:40 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

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

The wire spacing for 8P8C flat RJ45 connectors is about 1.05 mm. You
can\'t get the wires any closer to each other unless you contrive a 3D
connector that supports layers of 4 pair bundles.

If you want more density, and can tolerate more than one CAT5/6 cable
per connector, look into 25 pair telco connectors. The only problem
is that these are made for CAT3 and will probably not handle gigabit
ethernet speeds.
<https://www.amazon.com/Amphenol-MP-5T90MMUNNA-010-25-Pair-degree-50-Pin/dp/B00O07B8NW>

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

Amp (TE Connectivity) probably has higher density connectors that
might be convinced to work at gigabit speeds. I\'m too lazy to dig
through the catalog tonite:
<https://www.te.com/usa-en/plp/connectors/Y30Dq.html>

--
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

 

[Jasen Betts]

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\'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?

--
Jasen.

 

[Don Y]

On 10/1/2020 9:31 PM, Jeff Liebermann wrote:

On Thu, 1 Oct 2020 15:55:40 -0700, Don Y <blockedofcourse@foo.invalid
wrote:

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

The wire spacing for 8P8C flat RJ45 connectors is about 1.05 mm. You
can\'t get the wires any closer to each other unless you contrive a 3D
connector that supports layers of 4 pair bundles.

You don\'t need a connector body that\'s \"thicker\" than a few mm to
accommodate a single row of 8 conductors. Yet, 8P8C male mated to
receptacle is ~5/8\" \"thick\". I.e., the female connector body is approx
5/8 x 5/8 x 5/8 -- you don\'t need all of that just to terminate 8
conductors.

(the connector volume of a *40* conductor ribbon cable IDC PCB mount
is less than that)

If you want more density, and can tolerate more than one CAT5/6 cable
per connector, look into 25 pair telco connectors. The only problem
is that these are made for CAT3 and will probably not handle gigabit
ethernet speeds.
https://www.amazon.com/Amphenol-MP-5T90MMUNNA-010-25-Pair-degree-50-Pin/dp/B00O07B8NW

I don\'t need more than one cable termination. Note the 50pin
you cited is still \"bulky\" -- even if you omit the volume of
the backshell.

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

Amp (TE Connectivity) probably has higher density connectors that
might be convinced to work at gigabit speeds. I\'m too lazy to dig
through the catalog tonite:
https://www.te.com/usa-en/plp/connectors/Y30Dq.html

I think I\'m going to try to find an 8pin IDC ribbon termination
and see how well that works. I suspect if the pairs aren\'t overly
\"untwisted\" it should fare as well as a \"hand-made\" 8P8C (if you
look at how long each of the pairs need to be untwisted in each case)

If that works (electrically), then I\'ll have a similar connector
designed that makes installation easier (e.g., like \"pull thru\"
8P8Cs plugs)

 

[whit3rd]

On Thursday, October 1, 2020 at 10:04:13 PM UTC-7, Don Y wrote:

I think I\'m going to try to find an 8pin IDC ribbon termination
and see how well that works. I suspect if the pairs aren\'t overly
\"untwisted\" it should fare as well as a \"hand-made\" 8P8C (if you
look at how long each of the pairs need to be untwisted in each case)

The terminations that work for stranded wire (like in most ribbons)
are unsuitable for solid wire (like in most installations with in-wall wiring).
So, even if it WERE to work electrically, it might fail mechanically.
Since you\'re using telco-style punchdown blocks, you are probably using
solid wire.

Going through an RJ45 connector is a nice way to be able to test the wires... and
disconnect a client object without disturbing the cabling.

 

[Jeff Liebermann]

On Thu, 1 Oct 2020 22:03:56 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

>I don\'t need more than one cable termination.

How about an M8 or M12 ethernet connector?
<https://www.google.com/search?q=m8+ethernet+connector&tbm=isch>
<https://www.google.com/search?q=m12+ethernet+connector&tbm=isch>

--
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

 

[Don Y]

On 10/1/2020 10:30 PM, whit3rd wrote:

On Thursday, October 1, 2020 at 10:04:13 PM UTC-7, Don Y wrote:

I think I\'m going to try to find an 8pin IDC ribbon termination
and see how well that works. I suspect if the pairs aren\'t overly
\"untwisted\" it should fare as well as a \"hand-made\" 8P8C (if you
look at how long each of the pairs need to be untwisted in each case)

The terminations that work for stranded wire (like in most ribbons)
are unsuitable for solid wire (like in most installations with in-wall wiring).
So, even if it WERE to work electrically, it might fail mechanically.
Since you\'re using telco-style punchdown blocks, you are probably using
solid wire.

You can purchase 9P8C plugs for stranded or solid wire. So, it is obviously
possible to design a \"contact surface\" that will handle a solid OR stranded
wire. I.e., in production, that wouldn\'t be an issue.

As to prototyping, I can sidestep the whole \"contact point\" issue by soldering
conductors to the contact points intended to pierce/hug the individual
conductors (i.e., avoid the whole issue of the connection of PCB pin to wire
conductor)

Or, I can select stranded CAT5 cable.

The bigger issue (per my post) is the consequence of the chosen connection
type to the \"bounding volume\" of the completed assembly. Note that a
PCB header requires the cable to exit coplanar to the PCB. This isn\'t the
case with, for example, an 8P8C receptacle. (likewise, it\'s obvious that
you could redesign punchdown blocks for the conductors to exit normal to the
plane of the PCB -- though they would have to be located along an edge of
the PCB in order to be accessible to the punchdown tool.

Going through an RJ45 connector is a nice way to be able to test the wires... and
disconnect a client object without disturbing the cabling.

If solid wire, then you\'d want to avoid the \"moving connector\" or switch to
stranded wire.

In either case, once mated, the connection isn\'t expected to be \"serviced\".
When was the last time you dicked with any of the wires for your thermostat?
Doorbell? Irrigation controller? Automobile\'s ECU?

If you design the connector, then you can address \"removability\" in ways
that aren\'t possible with the 8P8C connectors (e.g., when a locking tab
breaks... you can\'t separate the cable from the connector body). For
example, if removability was a design goal, you could adopt a
\"hinged\"/compression mechanism similar to that used for flat conductors.

 

[whit3rd]

On Friday, October 2, 2020 at 6:42:58 AM UTC-7, Don Y wrote:

...once mated, the connection isn\'t expected to be \"serviced\".
When was the last time you dicked with any of the wires for your thermostat?
Doorbell? Irrigation controller? Automobile\'s ECU?

If the data throughput needs are minimal, could you fall back to two pairs,
and 10/100 speed limit? POE is still possible there... and a lot of the M8 data
connector literature is for four-wire Ethernet.

If you design the connector, then you can address \"removability\" in ways
that aren\'t possible with the 8P8C connectors (e.g., when a locking tab
breaks... you can\'t separate the cable from the connector body). For
example, if removability was a design goal, you could adopt a
\"hinged\"/compression mechanism similar to that used for flat conductors.

The highest speeds require jumble-wound wiring, though. Some kind of handwork for separation and
termination is going to be required, unlike flat cable.

 

[Don Y]

On 10/2/2020 1:59 PM, whit3rd wrote:

On Friday, October 2, 2020 at 6:42:58 AM UTC-7, Don Y wrote:

...once mated, the connection isn\'t expected to be \"serviced\".
When was the last time you dicked with any of the wires for your thermostat?
Doorbell? Irrigation controller? Automobile\'s ECU?

If the data throughput needs are minimal, could you fall back to two pairs,
and 10/100 speed limit? POE is still possible there... and a lot of the M8 data
connector literature is for four-wire Ethernet.

I can live without the CAT6 capability (and likely will have to cuz
CAT6 handles like \"thin orange hose\"!) I can\'t see how to successfully
create service loops, etc. in a small space with something that stiff
(it\'s a chore not putting kinks in CAT5e)

But, I\'d be unhappy downgrading to 100Mb (though I\'m presently only using
100Mb) as needs rarely seem to DEcrease, over time.

If you design the connector, then you can address \"removability\" in ways
that aren\'t possible with the 8P8C connectors (e.g., when a locking tab
breaks... you can\'t separate the cable from the connector body). For
example, if removability was a design goal, you could adopt a
\"hinged\"/compression mechanism similar to that used for flat conductors.

The highest speeds require jumble-wound wiring, though. Some kind of handwork for separation and
termination is going to be required, unlike flat cable.

Yes -- but that would also be the case if you were fitting 8P8C plugs
on the ends of the cable \"on site\".

If I design a connector, then I can make the \"cable side\" more friendly
to on-sit wiring; create guides/channels for individual conductors
instead of forcing the installer to try to keep the conductors in the
\"right\" order and carefully aligned (I could even CHANGE the order
to one that avoids the splitting of pairs BEFORE entry to the connector)

 

[Don Y]

On 10/2/2020 12:07 AM, Jeff Liebermann wrote:

On Thu, 1 Oct 2020 22:03:56 -0700, Don Y <blockedofcourse@foo.invalid
wrote:

I don\'t need more than one cable termination.

How about an M8 or M12 ethernet connector?
https://www.google.com/search?q=m8+ethernet+connector&tbm=isch
https://www.google.com/search?q=m12+ethernet+connector&tbm=isch

Even worse. The \"connector PAIR\" has to be small.

I.e., the 8P8C plug largely fits inside the 8P8C jack so
doesn\'t ADD much to the overall volume of the device
(incl connection).

That\'s why I thought the ribbon cable IDC header was
ideal; the \"connector\" itself is minimalist AND there
is no space required for its \"mate\" (as there is none).

The ideal would be a set of 8 thru-hole pads into which
the 8 conductors could be threaded and then \"cinched\"
without requiring the use of solder. Trim the excess
conductor length poking out the far side and your only
concern thereafter is strain relief (which, applied to the
insulated portion of the cable, could be secured to a
wide variety of surfaces without fear of short-circuit)

 

[Don Y]

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.

(there\'s very little mechanical force exerted on the cable/connection
after mating; mate-and-forget)

The imperative being minimizing the required volume of an encapsulating
enclosure (without having to place special constraints on that enclosure).
So, the \"connector\" has to consume minimal volume and offer flexibility
in how the cable exits wrt the PCB itself.

 

[Grant Taylor]

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 see them in all shapes, sizes, and number of connectors.

http://www.cnkeco.com/keco-terminal-block/71-screw-terminals.html



--
Grant. . . .
unix || die

 

[server]

Grant Taylor <gtaylor@tnetconsulting.net> wrote in
news:rl8smi$hqm$1@tncsrv09.home.tnetconsulting.net:

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 see them in all shapes, sizes, and number of connectors.

snipped link

You really do not know how modern high speed comms work then,
Grant.

Look at a true CAT6 connector. It has:

A: A shield/metal shroud that goes right up to the socket
insertion section. That shield is because the twisted pairs get
\'opened up\', as in \'untwisted\' for their termination into the
connector. No shield == not CAT6. exposed untwisted pairs... not
CAT6. Even that short little segment less than a half inch long
matters.

So yeah, if you want to dumb down your comm link to 15 years ago\'s
speeds then splay those motherfuckers out uncaringly.

Stick to \'net consulting\'. Your hardware acumen is lacking.

Modern PLC wiring is fully shielded. At least when one is talking
about automated assembly machines containing hundreds of connections
and pneumatic actuators and machine vision cameras, etc. Especially
automotive assembly machines where a failure results in high dollar
law suits by victims of said failures.

 

[Grant Taylor]

On 10/2/20 10:30 PM, DecadentLinuxUserNumeroUno@decadence.org wrote:

You really do not know how modern high speed comms work then, Grant.

Look at a true CAT6 connector. It has:

Per the OP\'s subject, CAT 5e is sufficient. CAT 6 is not required.

Depending on the distance that the OP wants to run cables, CAT 5e is
perfectly fine for the desired 1 Gbps speed.

> A: A shield ...

Is not required for 1 Gbps speed.

So yeah, if you want to dumb down your comm link to 15 years ago\'s
speeds then splay those motherfuckers out uncaringly.

The OP said that they did not want to fall back to 100 Mbps, which is
not required. CAT 5e will quite happily handle 1 Gbps.

> Stick to \'net consulting\'. Your hardware acumen is lacking.

Part of my net consulting is figuring out what clients actually need to
accomplish their goal. Part of that process is identifying potential
solutions. Potential solutions include things that don\'t actually
provide the answer but do provide information as to why they don\'t
provide the answer. Thereby providing more information to make it
easier to hone in on the solution.

There\'s no need for a personal attack. If you don\'t like the
suggestion, ignore it and move on.

I\'ve got multiple colleagues running full Gbps traffic across connectors
that fall into the family of what I suggested.

If the OP wanted 10 Gbps, that would be a different discussion. It
might even be different for 2.5 Gbps. But 1 Gbps is still fairly easy
to get and has a lot of options.



--
Grant. . . .
unix || die

 

[server]

Grant Taylor <gtaylor@tnetconsulting.net> wrote in news:rl90u4$sg0$1
@tncsrv09.home.tnetconsulting.net:

A: A shield ...

Is not required for 1 Gbps speed.

Nice snip.
I did not attack you. I said you lack hardware acumen. That is a
fact.

Your snip, however, while you rambled further, IS tantamount to an
attack.

Again... A TRUE CAT6 connector IS shielded, turkey turd. Not the
entire cable, it is not about the entire cable, JUST THE TERMINATION.
The cable is twisted pair and the termination IS important

And crosstalk and EMISSION occours without it and handshakes result
in SLOWER than 1Gb/s speeds.

Just like when you owned a \"56k\" modem but the damn thing never
hooks up faster than 14,400. It FALLS BACK to slower speeds.

So, IF too much untwisted pair segments are exposed, said fallback
DOES occur.

Reading what HE wrote, he DOES know that and wrote about closely
spaced PCB mounting.

 

[Jeff Liebermann]

On Fri, 2 Oct 2020 17:14:30 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:

On 10/2/2020 12:07 AM, Jeff Liebermann wrote:
On Thu, 1 Oct 2020 22:03:56 -0700, Don Y <blockedofcourse@foo.invalid
wrote:

I don\'t need more than one cable termination.

How about an M8 or M12 ethernet connector?
https://www.google.com/search?q=m8+ethernet+connector&tbm=isch
https://www.google.com/search?q=m12+ethernet+connector&tbm=isch

Even worse. The \"connector PAIR\" has to be small.

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>
Line 8 of these in a row on the surface of a PCB. Sweat solder the
sides of these pins to pads on the component side of the PCB. To make
it look good, use plastic separators or spacers, possibly 3D printed.
Or, just use a fixture that looks like an 8 pin \"fork\" to align and
hold the pins until they can be soldered to the PCB. Conjure some
kind of cable clamp to hold the CAT5 cable to the PCB, or just hot
melt glue it in place.

Solid conductor CAT5 is usually 24 AWG. The other CAT\'s can be
different gauges.
<https://www.cablexpress.com/blog/cat6-cabling-what-is-the-big-deal-about-awg-american-wire-gauge/>

Stranded conductor CAT5 will need the wire ends tinned and a larger
pin sockets to compensate for the added solder.

6.6 mm might be a little too short to get a decent grip on the CAT5
wires. Maybe something longer if you spare the PCB real estate.


Drivel: No new fires in the area so far. It\'s been very hot for the
last 3 days and probably will continue to be hot for the next two or
three days. I\'m holding my breath.

--
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

 

[Don Y]

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.)

I see them in all shapes, sizes, and number of connectors.

http://www.cnkeco.com/keco-terminal-block/71-screw-terminals.html

 

[Tom Del Rosso]

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
Line 8 of these in a row on the surface of a PCB. Sweat solder the
sides of these pins to pads on the component side of the PCB. To make
it look good, use plastic separators or spacers, possibly 3D printed.
Or, just use a fixture that looks like an 8 pin \"fork\" to align and
hold the pins until they can be soldered to the PCB. Conjure some
kind of cable clamp to hold the CAT5 cable to the PCB, or just hot
melt glue it in place.

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.

 

[Jeff Liebermann]

On Sat, 3 Oct 2020 15:50:40 -0400, \"Tom Del Rosso\"
<fizzbintuesday@that-google-mail-domain.com> wrote:

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
Line 8 of these in a row on the surface of a PCB. Sweat solder the
sides of these pins to pads on the component side of the PCB. To make
it look good, use plastic separators or spacers, possibly 3D printed.
Or, just use a fixture that looks like an 8 pin \"fork\" to align and
hold the pins until they can be soldered to the PCB. Conjure some
kind of cable clamp to hold the CAT5 cable to the PCB, or just hot
melt glue it in place.

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.

Good idea. However, it should probably be done using a managed 8 port
gigabit switch using SNMP to accumulate error counts by type of error
such as some of these:
<http://net-snmp.sourceforge.net/docs/mibs/EtherLike-MIB.txt>
dot3StatsIndex InterfaceIndex,
dot3StatsAlignmentErrors Counter32,
dot3StatsFCSErrors Counter32,
dot3StatsSingleCollisionFrames Counter32,
dot3StatsMultipleCollisionFrames Counter32,
dot3StatsSQETestErrors Counter32,
dot3StatsDeferredTransmissions Counter32,
dot3StatsLateCollisions Counter32,
dot3StatsExcessiveCollisions Counter32,
dot3StatsInternalMacTransmitErrors Counter32,
dot3StatsCarrierSenseErrors Counter32,
dot3StatsFrameTooLongs Counter32,
dot3StatsInternalMacReceiveErrors Counter32,
dot3StatsEtherChipSet OBJECT IDENTIFIER,
dot3StatsSymbolErrors Counter32,
dot3StatsDuplexStatus INTEGER,
dot3StatsRateControlAbility TruthValue,
dot3StatsRateControlStatus INTEGER
etc...

Managed gigabit switches cost somewhat more than unmanaged gigabit
switches:
<https://www.amazon.com/NETGEAR-PROSAFE-8-PORT-GIGABIT-SWITCH/dp/B003GOFIC2>

Unfortunately, managed switches usually don\'t test for important cable
parameters such as low signal levels, reflections, NEXT (near end
crosstalk), and excessive attenuation. Therefore, a gigabit network
cable tester should also be used along with a TDR (time domain
reflectometer) to look for impedance discontinuities. Some cable
testers and certifiers have a built in TDR, but external is usually
good enough:
<https://www.ebay.com/itm/TDR-Time-Domain-Reflectometer-Fast-Clock-USB-Power-Detect-cable-faults-More/153549738452>


--
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

 

[Don Y]

On 10/2/2020 10:34 PM, Jeff Liebermann wrote:

On Fri, 2 Oct 2020 17:14:30 -0700, Don Y <blockedofcourse@foo.invalid
wrote:

On 10/2/2020 12:07 AM, Jeff Liebermann wrote:
On Thu, 1 Oct 2020 22:03:56 -0700, Don Y <blockedofcourse@foo.invalid
wrote:

I don\'t need more than one cable termination.

How about an M8 or M12 ethernet connector?
https://www.google.com/search?q=m8+ethernet+connector&tbm=isch
https://www.google.com/search?q=m12+ethernet+connector&tbm=isch

Even worse. The \"connector PAIR\" has to be small.

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.

Line 8 of these in a row on the surface of a PCB. Sweat solder the
sides of these pins to pads on the component side of the PCB. To make
it look good, use plastic separators or spacers, possibly 3D printed.
Or, just use a fixture that looks like an 8 pin \"fork\" to align and
hold the pins until they can be soldered to the PCB. Conjure some
kind of cable clamp to hold the CAT5 cable to the PCB, or just hot
melt glue it in place.

Solid conductor CAT5 is usually 24 AWG. The other CAT\'s can be
different gauges.
https://www.cablexpress.com/blog/cat6-cabling-what-is-the-big-deal-about-awg-american-wire-gauge/

Stranded conductor CAT5 will need the wire ends tinned and a larger
pin sockets to compensate for the added solder.

6.6 mm might be a little too short to get a decent grip on the CAT5
wires. Maybe something longer if you spare the PCB real estate.

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.

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

Drivel: No new fires in the area so far. It\'s been very hot for the
last 3 days and probably will continue to be hot for the next two or
three days. I\'m holding my breath.

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