Re-assignable DB9 Connectors?

[TheWaterbug]

TL;DR: Help me find DB9 connectors with removable/reassignable contacts?

I sell little modules for distribution, translation, and switching of (mostly) digital signals, typically with coax connectors:


Sometimes my customers want to put a bunch of these in a rack mount chassis with mass-terminated connector(s), often D38999-style circular connectors. So we sell D38999 connector kits, with the coax cables terminated with a pair of D38999-style contacts, for the customers to insert into standard D38999 housings as they see fit:



A single coax gets pinned out to two D38999 contacts for signal and shield/GND, and a pair of coax gets pinned out to three D38999 contacts for signal+, signal-, and common shield/GND. There is no "standard" pinout, nor even any standard for which pins are GND, which is why the D38999 is popular, because you can assign the pins any which way you want.

Lately I've gotten several inquiries from customers who want to do exactly this, but with DB9 connectors at the edge of the box. Most DB9 connectors I've seen are solder-cup or PCB-mount, neither of which lends themselves to arbitrary re-assignment of pins in the way that D38999 contacts make possible. I can't just make a "standard" DB9 cable, because there is no standard for generic adaptation of signals if it isn't a serial COM port.

I'm looking for a non-soldering solution, as this is for system integration folks who want to play with these like Legos™ before they commit to a final design.

Do re-assignable DB9 connectors exist? I'd be looking for both genders, and both panel-mount and cable-end varieties for each, as there doesn't seem to any standardization on that area, either.

Thanks!

[themadhippy]

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

[thm_w]

Can't you wire each pin of the DB9 with say a female dupont crimp and then they can connect it to various points on the board?

There is also stuff like this but not sure if its what you are asking for: https://www.aliexpress.com/item/1005009543087275.html

[profanum429]

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

Yep, pretty sure this is exactly what he needs.

Bonus, if you've got the crimper for 38999 contacts then you probably can just get a new positioner for M24308 pins/contacts.

[jpanhalt]

This is what I use:


I got it from Amazon but can't find the exact thing this morning.  It allows arbitrary male to female pin mappings with jumpers. 

[bitwelder]

There should be around also DB9-to-RJ45 adapters, where the DB9 side has the wires plugged already (so no need for a crimping tool), but you'll need to decide the DB9 slot for each pin. Then you'll use a regular twisted pair cable of appropiate length to go from one end to the other of your connection.

[TheWaterbug]

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

Yep, pretty sure this is exactly what he needs.

Bonus, if you've got the crimper for 38999 contacts then you probably can just get a new positioner for M24308 pins/contacts.

Yup! This looks to be exactly what I was looking for. I don't know why I didn't find it earlier. I suppose I was just using the wrong vocabulary.

I'm going to order a few pieces and see how similar it is to 38999 assembly.

Thanks!

p.s. those other suggestions look interesting, but the far side of the sub-cables is going to be SMA.

[MLXXXp]

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

Another alternative brand for the same (or similar) thing:
https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=1308940_Sec8_amplimite&DocType=CS&DocLang=English&DocFilename=ENG_CS_1308940_Sec8_amplimite_0118.pdf

I'm sure there are other brands out there, as well.

And note that technically, it's DE9 (9 pins in an E size shell), not DB9, but DB9 has become popular and understood, just like JST is often used for other brands of similar but incompatible connectors.

[tooki]

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

Yep, pretty sure this is exactly what he needs.

Bonus, if you've got the crimper for 38999 contacts then you probably can just get a new positioner for M24308 pins/contacts.

Yup! This looks to be exactly what I was looking for. I don't know why I didn't find it earlier. I suppose I was just using the wrong vocabulary.

I'm going to order a few pieces and see how similar it is to 38999 assembly.

There’s no special name for them — they’re just crimp-style D-sub connectors.

The vast majority use compatible pins and housings. So shop around, including looking at the generic mil-spec part numbers for the contacts (M32029/64-369 and M32029/63-368 are the most common types, for male and female, respectively), as they may be cheaper. Molex/FCT also tends to be well priced.

A few years ago I compiled a cross-reference guide for the contacts and tooling; I could dig it up if you need.

A little pro tip for you, after some back and forth with one of the manufacturers about the difference between two seemingly-identical series of housings: some have metal contact retention clips, others do not. The ones with the clip can be used with both machined and stamped contacts, while the kind without the metal clips must be used with machined contacts.

Since I like machined contacts better anyway, I just buy the M32029/64-369 and M32029/63-368 and use them with whatever housings I want.

There are dedicated insertion/extraction tools for these, from $$$ tools from DMC all the way to disposable plastic ones that cost a dollar; all of these are defined in mil specs and so they’re widely available and the plastic ones are very cheap.

[Cyclotron]

And note that technically, it's DE9 (9 pins in an E size shell), not DB9, but DB9 has become popular and understood, just like JST is often used for other brands of similar but incompatible connectors.

Similarly the "recommended standard" RS-232 is the actual standard TIA-232. But everyone knows what folks mean when they say RS-232. 

Another one is the common reference to ethernet cable ends as rj45 but they are actually Mod8 (8P8C). rj45 is an obsolete wiring standard.

I purchased a set of male and females from amazon.
https://www.amazon.com/dp/B0CBJYXZGJ?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_6&th=1

[tooki]

Do re-assignable DB9 connectors exist? I'd be looking for both genders, and both panel-mount and cable-end varieties for each, as there doesn't seem to any standardization on that area, either.

What?!? They’re arguably among the most-standardized connectors on the planet. They’re very modular, so perhaps it’s not obvious to you that the connectors for panel- and cable-mount applications are the same. Fundamentally, you just attach the retention nuts, retention screws, and backshell to the respective parts as needed. (You can get some connectors with the nuts integrated or attached, which does reduce their flexibility. But most don’t.)

[EPAIII]

Knowing the correct search terms is called "Google Fu". We all get caught up by it at one time or many.

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

this sorta thing?  https://www.digikey.co.uk/en/products/detail/amphenol-positronic/M24308-2-1F/11617886

Yep, pretty sure this is exactly what he needs.

Bonus, if you've got the crimper for 38999 contacts then you probably can just get a new positioner for M24308 pins/contacts.

Yup! This looks to be exactly what I was looking for. I don't know why I didn't find it earlier. I suppose I was just using the wrong vocabulary.

I'm going to order a few pieces and see how similar it is to 38999 assembly.

Thanks!

p.s. those other suggestions look interesting, but the far side of the sub-cables is going to be SMA.

[Cyclotron]

Knowing the correct search terms is called "Google Fu". We all get caught up by it at one time or many.

I don't know if Google made it better or worse. I used to be a fan of "Altavista" and it was super important to get your boolean search terms and operators proper to get good results. I still use similar techniques with google but more relaxed.

Use of AI search can be dramatically easier, but it remains to be seen if it is "better".

[tooki]

I don't know if Google made it better or worse. I used to be a fan of "Altavista" and it was super important to get your boolean search terms and operators proper to get good results. I still use similar techniques with google but more relaxed.

Use of AI search can be dramatically easier, but it remains to be seen if it is "better".

It’s maybe better than the awful the-only-reason-you-search-for-things-is-shopping disaster that Google search has been turned into, but I don’t think it’s anywhere near as good as Google search was before they ruined it.

One thing I never liked about Google search was the lack of robust support for Boolean search operators. They’ve only ever had half-assed support for them, and the enshittified Google now often ignores them if it can’t find anything.

[KrudyZ]

Going from coax through a DB9 connector and back to coax will really mess with your signal integrity.
If that is of concern then there are better solutions for this:
https://www.molex.com/en-us/products/rf-microwave-technology/multi-port-rf-coaxial-cable-to-board

[tooki]

Going from coax through a DB9 connector and back to coax will really mess with your signal integrity.
If that is of concern then there are better solutions for this:
https://www.molex.com/en-us/products/rf-microwave-technology/multi-port-rf-coaxial-cable-to-board

If it works adequately with the M38999 circular connectors and ordinary pins, it’ll work with a D-sub and ordinary pins.

And if it should become an issue, coaxial contacts (that fit into the normal connector cavities!) do exist.

[tooki]

I just got around to looking at OP’s website. I wouldn’t be surprised if there are some of their products in use in the laser labs I support.

But man, I wouldn’t have the balls to charge those prices — $23 for a 2-pin twisted-pair header cable, $29 for a pack of 10 zip ties… 

I get it that the core products aren’t mass-market products with large numbers of customers, but damn… no wonder my predecessors in the department built so much similar stuff (clock dividers, pulse transmitters, etc.) themselves!

And similarly, I wouldn’t have had the balls to apply for the two patents they received (both expired by now), as they strike me as flagrant violations of the law applicable at the time:

Pre-AIA 35 U.S.C. 103  Conditions for patentability; nonobvious subject matter.
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.

(Pre-AIA means before the 2011 “America Invents Act” revision of the law.)

Both patents apply to simple breadboard adapters (breakout boards), the likes of which existed long before they applied for the patents in 1999:
https://patents.google.com/patent/US6407652B1/en
https://patents.google.com/patent/US6265952B1/en

[Cyclotron]

One thing I never liked about Google search was the lack of robust support for Boolean search operators. They’ve only ever had half-assed support for them, and the enshittified Google now often ignores them if it can’t find anything.

Thank you! You made me actually LOL.  I love that term for a means to quickly communicate how proper and good tools and applications have turned into big turds.

You are of course 100% right. When Google started I got an early view of it from a friend that consulted on investments. He argued with me that Altavista would soon be wiped from the internet. The first time I plugged in a few search terms he told me that he'd pay me 50 bucks if I didn't accept the page that came up when if I pushed "I'm feeling lucky."  He didn't pay me.

It was pure math and pure magic to see. Then, as you say, Enshittification happened.

Thanks again.

[Cyclotron]

I just got around to looking at OP’s website. I wouldn’t be surprised if there are some of their products in use in the laser labs I support.

But man, I wouldn’t have the balls to charge those prices — $23 for a 2-pin twisted-pair header cable, $29 for a pack of 10 zip ties… 

I get it that the core products aren’t mass-market products with large numbers of customers, but damn… no wonder my predecessors in the department built so much similar stuff (clock dividers, pulse transmitters, etc.) themselves!

And similarly, I wouldn’t have had the balls to apply for the two patents they received (both expired by now), as they strike me as flagrant violations of the law applicable at the time:

Pre-AIA 35 U.S.C. 103  Conditions for patentability; nonobvious subject matter.
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.

(Pre-AIA means before the 2011 “America Invents Act” revision of the law.)

Both patents apply to simple breadboard adapters (breakout boards), the likes of which existed long before they applied for the patents in 1999:
https://patents.google.com/patent/US6407652B1/en
https://patents.google.com/patent/US6265952B1/en

I think your link to the OP is wrong? 
https://www.pulseresearchlab.com/ is the one I think is right and the one in your post, lol, goes here:
https://www.pulseresearch.com/

Which I can see someone needing a lot of to sell some 29 dollar pack of 10 zip ties.
Dang, that's twice in one thread I've litterally LOL'd.

[tooki]

I just got around to looking at OP’s website. I wouldn’t be surprised if there are some of their products in use in the laser labs I support.

But man, I wouldn’t have the balls to charge those prices — $23 for a 2-pin twisted-pair header cable, $29 for a pack of 10 zip ties… 

I get it that the core products aren’t mass-market products with large numbers of customers, but damn… no wonder my predecessors in the department built so much similar stuff (clock dividers, pulse transmitters, etc.) themselves!

And similarly, I wouldn’t have had the balls to apply for the two patents they received (both expired by now), as they strike me as flagrant violations of the law applicable at the time:

Pre-AIA 35 U.S.C. 103  Conditions for patentability; nonobvious subject matter.
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.

(Pre-AIA means before the 2011 “America Invents Act” revision of the law.)

Both patents apply to simple breadboard adapters (breakout boards), the likes of which existed long before they applied for the patents in 1999:
https://patents.google.com/patent/US6407652B1/en
https://patents.google.com/patent/US6265952B1/en

I think your link to the OP is wrong? 
https://www.pulseresearchlab.com/ is the one I think is right and the one in your post, lol, goes here:
https://www.pulseresearch.com/

Which I can see someone needing a lot of to sell some 29 dollar pack of 10 zip ties.
Dang, that's twice in one thread I've litterally LOL'd.

Oops you’re absolutely right, thanks for the heads up. I’ll edit my post to fix it.

[TheWaterbug]

A few years ago I compiled a cross-reference guide for the contacts and tooling; I could dig it up if you need.

A little pro tip for you, after some back and forth with one of the manufacturers about the difference between two seemingly-identical series of housings: some have metal contact retention clips, others do not. The ones with the clip can be used with both machined and stamped contacts, while the kind without the metal clips must be used with machined contacts.

Since I like machined contacts better anyway, I just buy the M32029/64-369 and M32029/63-368 and use them with whatever housings I want.

There are dedicated insertion/extraction tools for these, from $$$ tools from DMC all the way to disposable plastic ones that cost a dollar; all of these are defined in mil specs and so they’re widely available and the plastic ones are very cheap.

Thanks! Yeah, I think I want the military-style contacts (e.g. M32029/64-369 and M32029/63-368) because that pretty much guarantees inter-operability all the way down to the contact and tooling level.

[TheWaterbug]

Another one is the common reference to ethernet cable ends as rj45 but they are actually Mod8 (8P8C). rj45 is an obsolete wiring standard.

I purchased a set of male and females from amazon.
https://www.amazon.com/dp/B0CBJYXZGJ?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_6&th=1

Whoa! These look great, at least for low-speed applications. We also make some of our translator modules with 8P8C  connectors:


and those kits would make adapting to DB9 even easier.

Do you know if the DB9 contacts are M32029/64-369 and M32029/63-368 or at least similar?

I'm glad it's an arbitrarily assignable kit, because there aren't really any standard pin assignments for using Category cable for non-Ethernet and non-RS232 applications.

[TheWaterbug]

Going from coax through a DB9 connector and back to coax will really mess with your signal integrity.
If that is of concern then there are better solutions for this:
https://www.molex.com/en-us/products/rf-microwave-technology/multi-port-rf-coaxial-cable-to-board

If it works adequately with the M38999 circular connectors and ordinary pins, it’ll work with a D-sub and ordinary pins.

And if it should become an issue, coaxial contacts (that fit into the normal connector cavities!) do exist.

Yup. We ran 500 MHz TTL through two lengths of RG-174 connected in the middle with 38999 pin and socket contacts, and it still (barely) made TTL thresholds:



We tried the true coaxial inserts as well, and were somewhat surprised that the results were not noticeably better.



We did see an improvement in waveform using LVPECL instead of TTL, because the original rise/fall times are so much faster. White Math channel is Ch 1 - Ch -2:



but I probably need to repeat the LVPECL experiment with the non-coax contacts to have a true A/B comparison. I was also driving the LVPECL with the original complementary TTL signal, DC-coupled, and while the TTL has pretty good symmetry and +/- skew, I might have been better off AC-coupling into the LVPECL receiver single-ended, and seeing if the symmetry was any better that way.

Or just using an ECL clock source to begin with.

So many experiments; so little time.

[TheWaterbug]

I just got around to looking at OP’s website. I wouldn’t be surprised if there are some of their products in use in the laser labs I support.

But man, I wouldn’t have the balls to charge those prices — $23 for a 2-pin twisted-pair header cable, $29 for a pack of 10 zip ties… 

I get it that the core products aren’t mass-market products with large numbers of customers, but damn… no wonder my predecessors in the department built so much similar stuff (clock dividers, pulse transmitters, etc.) themselves!

Different strokes for different folks. We sell primarily to aerospace, and it's an every day experience for us to get a 30 page purchase order, with all its attendant clauses for Quality, and Buy American, and Specialty Metals, and cyber security and parts traceability . . . for a $95 part. 

And now that buyer has to make a decision as to whether to add a $23 cable to that order to me, or generate another 30 page PO to buy it for $2.00 somewhere else. We don't make any money on this sale in any case; we're not efficient at all at selling $20 anythings. We provide the small accessories as a convenience so that they can buy the meaningful stuff.

[KrudyZ]

Running a single frequency signal and looking at it with a scope doesn't tell the whole story.
A bit error rate tester will give you information on inter symbol interference, line loading, etc.
Minimally run a pseudorandom bit sequence and see how your eye looks at various data rates that are of interest to you.