DE-5000 Future-Proof Upgrade ( Kelvin Clips, or others to 1 unit ) - suggestions

[Acecool]

I ordered another TL-22 off eBay for $20 USD ( I could've paid $18.88 USD on Amazon for TL-21 but the alligator clips are useless to me and short, but the tweezers I can attach other ends to and it'll be an upgrade from my current ones and then I can use the box for something else )...

I keep seeing videos showing people either removing the ends of kelvin clips, or cutting the wires and soldering them to one of the DE-5000 modules but this isn't future-proof. You can always resolder something, sure.. but to be of most use there should be a different way... So I've come up with a solution...

One of the ideas being passed around was to have a single module and 4 BNC connectors mounted to it - there are a lot of problems with this: There isn't much room, it doesn't fit with the current design so it'll need to be modded or a new case needs to be 3D printed meaning less available and depending where you mount the wires they could be a burden.... I did find a BNC Female 4 connections in 1 2x2 layout which is 36x31x32mm so it could fit, but it'd be bulky... It'd require cutting. And it'll require extra markings... I wanted to look for a 1x4 layout and check the measurements because I could use that for my solution and use heat-shrink wrap around it but I think there is a better way...

So, BNC Wires Female to Female should be available on eBay for a low price... Cut them in half and wire them up to one of those aircraft connectors with the seal ( which are typically used on the Chinese knockoff Rework / soldering stations )... The benefits of this is you can have a single wire coming out of the module with a female adapter to give flexibility, and it'll be wired with the 6 leads needed ( 2x per plus shield - although I may go for the 8 so each shield can have its own pin and then I can alternate them but the 8 pin variant has a pin in the center )... Then an adapter is made for each type of system you want to use... So you can make the attachment for BNC kelvin clips, and many more.... But once the adapter is made, it's made, and once the adapter to convert the 8 pin or 6 pin connector to the standard is made, then that's also done....

The wires will come off in a similar fashion as the kelvin clips which have heat shrink around the double-wires so the two negatives are together and two positives are together... and they'll be joined until about the mid-way to give a few inches of flex and separation at the connectors, while still keeping them together...



Now, my questions are as follows:

- Is there any reason why this wouldn't work? I know that connecting between multiple connectors adds resistance, but the 4 wire testing system is supposed to negate all of that....
- Will 8 pins be too much for the single connector? ie are they too close together - should I separate into 2 4 pin connectors instead? The reason I want to keep the wires isolated is because that's how it's done in the actual wires leading up to the clips so it'll be uniform all the way to the PCB.... So 1 signal wire, plus 1 shield...
- From the previous: Should I use 2 4 pin connectors instead? Then the signal wires can be diagonal and the shields can be too... This means more connectors are needed for each adapter, but if it helps keep signals isolated then that's better...
- Do you have any additions or ideas to make this project better?


The main reasons I am picking this strategy is because it is a simple project which can be more widely used instead of requiring a 3D printer or going through expensive manufacturers, which would also limit you to a certain angle of connectors, etc...

As of right now, I'm going to go ahead and purchase the 8 pin and 4 pin connectors needed to make this happen and the shielded BNC Female to Female wires... I'll happily add links to each and every item I use in the build and I'll make videos and add photos when everything arrives...


Notes:
- Right now I'm thinking of using the 4 pin GX16 connectors with 1 per side so 2 needed... From a single connector 2 connectors will come so from the GX16-4 - side 2 BNC Female ports will accept the negative kelvin clips, and same on +...  This means 2 wires coming from the TL-22 unit coming out and they'll be easily marked, from those 2 4 wires ( the adapters will be identical so there's at least that )... I'll ensure the wiring is done identically on both sides and marked so if anyone follows this they will be able to like the wires up to the ports and done.. - Next step is to find some good wiring to go from the GX16 connectors into the unit, and then deciding if I'm going to get a Y splitter ( which seems to be all they have in terms of wires with 2 female connectors on eBay ) M to 2*F or M to F *4 which will be pricey and chop them in half, or buy the connectors and make my own wires.... The benefit of the preconstructed is that the reliefs will be good quality, in most cases...
- I am still considering a single GX16-8 from the unit so one wire into 4 ( or even 2 with a double BNC 1x2 female plate coming out of the end of the adapter wire )... Benefit is 1 wire, 1 plug and then clearly marked splitters but if theres interference then thats no good - I'll probably try both ways even if it means making another adapter and then seeing what I prefer...

Purchases:
- TL-22 ( The DE-5000 adapter with the tweezers ) :: $20 USD Delivered from :: https://www.ebay.com/itm/DER-EE-Chip-Probe-TL-22-SMD-for-DE-5000-New-in-Box/312091713364?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 :: Note: I chose this option because I can use the tweezers - you can get the TL-21 on Amazon for $18.88 but the alligator clips aren't really worth as much as the tweezers and I know they're worth more than the $1.12 difference...
- GX16-4 ( 4 pin screw on connector male and female ports ) :: $3.77 USD Delivered from :: https://www.ebay.com/itm/5pcs-Aviation-Plug-4-Pin-16mm-GX16-4-Metal-Female-Male-Panel-Connector/272488501093?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
- Kelvin Clips :: $12.85 each * 2 :: https://www.ebay.com/itm/1-Set-Kelvin-Clip-with-4-BNC-Male-Test-lea-cable-Wires-for-LCR-Meter/372305358126?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[bugi]

Only bit of info I can give is from the chipset's pdf:
"Open condition requirement: Impedance is
larger than 9.5MΩ @ 1kHz
Short condition requirement: Impedance is less
than 1.1Ω"

Otherwise the calibration might not work.  I've seen videos which mention failing calibration (I don't remember the specifics), so there seems to be at least some limitations.

[Acecool]

Interesting - it may not be possible then with all of the connectors....

I'll be the guinea pig, and if it works then we'll have a viable solution for all - and if it doesn't, I can use the parts elsewhere and simply solder the kelvin clips directly...

[Acecool]

Alright, just a quick update...

I received the clips, a lot of connectors ( I bid on a ton and paid at most 20 to 25 cents each or so - some less... and they arrived very quickly ( 10 to 14 days ) and look to be high quality... I purchased GX16-4 and GX16-8 connectors ( these are the screw on connectors with 4 and 8 pins with a size of 16mm ). The clips  seem to have thinner wires than I thought they would have but seem ok... I had to bend the tips a little in order to get the teeth to line up better than they did to start with...

I may modify the clips later so one wire goes to each arm / lever, insulate the spring to ensure it is true 4 wire loop...

I did finally find BNC Female to Female wires - I purchased 2. I cut one in half to check the quality and it seems good. Copper shield instead of steel or aluminum..


I drew a copy of the pcb to lay out my design options... I'm still waiting on my second TL-22 ( I chose the tweezers so I could attach bnc connectors or whatever and use them with this future-proof mod and so I could also attach other connectors and use them where-ever...


I did a few size tests... If I want to use the GX16-8 plug, then I'll need to remove the entire outer cover for the cable, and then add heat-shrink wrapping to the core and put it through the end this way... Then I'd either need to buy or 3d print, or make an end with a glue-gun by making a mold so the wires will have tension relief... Otherwise the overall size of the wires is way too large to fit. Second, if I use the BNC wires directly from the PCB the original hole won't fit so I'd either need to create an extra hole, or 2 holes ( and weld the center with the material removed ) - I'd prefer the 2 hole option because they'd be offset evenly and it'd be clear as to negative vs positive. Although a center and left or right hole would work too if I shave down the exterior of the wire a little bit which would actually create a tension relief so that's not bad either...

Using the GX16-4 plug, both BNC wires fit in, just barely and tighten all the way down flattening the inner hard plastic core, etc.. and the raised walls in the end of the connector creates a stress-relief...

I wrote down benefits and negatives of using either....


Pros using GX16-4
- Much easier to manufacture as one or 2 wires can come from the unit per side so you'd have 2 GX16-4s hanging off... But the adapter from GX16-4 to BNC or other connector will split into 2 so 1 wire to plug -> plug to 2 wires to BNC or other -> to units and this can stay plugged in...
- You can also leave the adapter plugged into the clips since it is easier to manufacture so I can make a few then I only have 2 plugs to connect... ( I may make an added adapter to go from the 2 GX16-4s to a single GX16-8 and then leave them plugged in so only one plug needs to be plugged in to swap between clips but it means more to manufacture...
- Wider spacing between pins - also the GX16-4 I got has a center shield between all 4 connectors shaped like a + to prevent contact... I'm disappointed the 8 pin doesn't have this.

Cons using GX16-4
- 2 plugs to use when plugging the adapter into the unit which then turns into 4 wires to plug into the clips - I could simply keep the adapters plugged in and then I'd only need to plug in 2 if I make more adapters...
-
-


Pros using GX16-8
- A single plug to attach / detach to the unit but you still need to connect all 4 wires with the clips... Maybe faster than the other option...
- I can either use 6 pins and leave the center and bottom pin un-used by combining grounds which is done anyway, ( although other units may not do this? ), use 5 pins by using the center 8 pin as shared ground and give a pin of space between each signal wire. But this is on the line of pro because I could've just purchased 5 pin connectors ( I may do that too and try different ways - I can always re-use plugs so it isn't wasting anything )
-

Cons using GX16-8
- Originally I thought using the 8 plug would be annoying because of the layout, but it seems ok - the big problem is the spacing... not a lot of room..
- I'd have to create an adapter for the GX16-8 plug so depending how it is done, there will be either 1 to 4 wires going in from the unit, and 4 wires coming out - tight fit, hard to make...
- The 8 pin connector doesn't have a built in shield meaning I'd need to manually shield or cover the wires inside the cover ( maybe I don't, but I do it anyways )...


Overall Pros
- 'Future proof': I'd only need to make an adapter to use different clips, or whatever.

Overall Cons
- All designs which add cable length, connectors, etc.. will add impedance and resistance - at a certain limit it will not work so I need to make sure to check all when doing this...


Note: I won't be using ALL of the BNC male / female connectors with the green easy wire connects ( I got them for testing ) or the power supply connectors ( same ) but I will hold on to a few... If anyone needs any of these and lives near Hendersonville NC and is interested in a few, I don't mind sharing for what I paid for them ( some as low as 5 or 10 cents each if I recall correctly ) and if I need to ship then media male can be shipped in a pvc mailer ( up to 9 day shipping ) and is usually $2 for really heavy weights... It'd be ok as long as I include some company swag or a Thank you for your interest in my company letter! I also have a ton of 1p, 2p, 3p, 4p and 5p dupont standard connectors, and also male / female pins for them.. for arduino, etc.. single / double row, headers too and I have voltage regulators AMS1117 in ADJ, 1.2, 1.5, 1.8, 2.5, 3.3, and 5.0V.. I have SC 8.000 oscillators, ws78L05s, PT4115s, bright SMC LED 3.3v, usb micro SMC 5p with the 2 plastic keys which can be removed. USB Micro Breakout boards for testing....

I'm not looking to profit off spare components so if anyone is interested in it for hobby or to teach, you pay what I paid ( and I only look for the best deals and ROHS )...



Here are some photos of the parts accumulated so far, and of the design options. Design 1A is likely what I'll be doing. 2B seems too much of a hassle and 2 means making another hole in the TL-22 case...

All 10 photos:
https://www.dropbox.com/s/2900dp6is107ek5/DER_DE-5000_Future_Proof_Connector_Mod.zip?dl=0

Overhead of clips with cut female wires attached and some connectors at the top partly out of frame.
https://www.dropbox.com/s/fsuudbtm5uyywg5/20180610_082534.jpg?dl=0

Basic plans:
https://www.dropbox.com/s/nmmjkhtwjzqm4dh/20180610_083402.jpg?dl=0

Connectors in foreground and top right has the clips / wires along with the TL-22 tweezers and board there... Red container is for 'food' ( 2 or 3 for $1 and they word great for parts / repairs, etc.. for storing disassembled part screws, etc.. ) the other plastic containers are absolute trash - I bought them at Harbor Freight in a larger container containing these containers and they are loose fitting and they are soft but not the soft which helps seal them, the soft but less pliable meaning things will escape if parts aren't big enough... Some of the GX16-4 and 8 connectors at the bottom, some BNC Male and Female to RCA connectors and the Black / Green tester or camera BNC connectors in Male and Female in the middle on the left side... The red container is holding some of the parts to be used in the build, disassembled and ready to be used....
https://www.dropbox.com/s/922j78hryuaop7g/20180610_083107.jpg?dl=0


I still need to measure the impedance and resistance so it may actually be that I will be required to go a direct route which I wouldn't be to excited about, but we'll see.... Once I measure everything up I'll see what I can get away with now that I have everything basically ( still need color coded heat-shrink wrap, I want to split the wires apart on the clips themselves, and color code the wires and the adapters ( even though the adapters will be identical so it won't matter, but having color-coding is helpful to avoid issues ), and when I receive the replacement TL-22 I'll either mod THAT one, or I'll simply mod the one I have here and put that one back into my toolbag...


I do plan on making a video when I start the build - I won't have some of the steps in it such as cutting the wire but I'll list where I purchased all of the parts, and tips and tricks to help measure bent-wire accurately and so on as well as the actual assembly, calculating ( adding ) the impedance / resistance to make sure it'll work ( first part ) and more... The goal with the video is to help as many complete this build for as little as possible ( and since the TL-21 and TL-22 are identical except for the TL-2X marking and the soldered clips vs tweezers anyone can use what they want - as said I am using the TL-22 because I wanted the tweezers as an upgrade to my $1 set I purchased on eBay which fail the units calibration and this new set will essentially cost $1.12 since that's the amount extra I paid extra for the TL-22 over the TL-21 ( with the 21 being on amazon and the 22 on eBay for $20 flat USD )....


Current links will be added to top post. I'm not receiving any payment to advertise these eBay sellers, these are simply who I purchased from. I will only list the parts I know I will use in the build ( I won't include the loose connectors with the green unless someone asks for them )...


1 Set Kelvin Clip with 4 BNC Male Test lea cable Wires for LCR Meter ( Quantity: 2 for ITEM PRICE: US $25.70 TOTAL )
https://www.ebay.com/itm/1-Set-Kelvin-Clip-with-4-BNC-Male-Test-lea-cable-Wires-for-LCR-Meter/372305358126?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

DER EE Chip Probe TL-22 SMD for DE-5000 New in Box ( Still waiting to receive )
https://www.ebay.com/itm/DER-EE-Chip-Probe-TL-22-SMD-for-DE-5000-New-in-Box/312091713364?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649


1M 75ohm BNC Male to Male Male to Female Female to Female Coax CCTV Cable Cord - Connector A-BNC Female to BNC FemaleConnector A: BNC Female to BNC Female Quantity: 2 ( US $3.98 + US $0.38 )
https://www.ebay.com/itm/1M-75ohm-BNC-Male-to-Male-Male-to-Female-Female-to-Female-Coax-CCTV-Cable-Cord/253648419922?ssPageName=STRK%3AMEBIDX%3AIT&var=552884833361&_trksid=p2057872.m2749.l2649

5Pcs 8-Pin 16mm GX16-8 Aviation Plug Power Chassis Male Female Panel Connector
https://www.ebay.com/itm/5Pcs-8-Pin-16mm-GX16-8-Aviation-Plug-Power-Chassis-Male-Female-Panel-Connector/372299960350?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

5pcs Aviation Plug 4-Pin 16mm GX16-4 Metal Female Male Panel Connector
https://www.ebay.com/itm/5pcs-Aviation-Plug-4-Pin-16mm-GX16-4-Metal-Female-Male-Panel-Connector/272488501093?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[WhichEnt2]

Why don't you just use db9 or something like that?
There were opinions about that chinese aviation connectors doesn't really work well in small signals cause their sockets made of nickel or something like that.

[Acecool]

I have a few DB9 connectors but they're SMCs...

Once I calculate the resistance and impedance of everything, I'll post all of the results here...

I started on the video - I, before testing any of the values, have created a basic test rig.... and it passed...

I'm using a few of the connectors I purchased on eBay and the uncut kelvin clips...

So, I had some Radio Shack 100 foot in-wall CM style Cat5 solid-copper-wire length so I cut 2 at about 7 inches each and removed the wires from both - I left them twisted as that helps with signal... I used all of the solid white with x color stripe for shield / ground wires.. Then the colored wires for -1, -2 and +1, +2 signal wires. I am using 2 separate wire sheathes to help keep them separate since I haven't added any coloring yet ( ordering color-coded heatshrink so I can also redo the clips so I can isolate the spring in the clips and ensure one wire goes to each side... I then used a screw-terminal BNC Female to attach the Cat5 to and then I connected them to the clips..

For the soldering, I didn't go through the through-hole because this was a temporary test to make sure it will work - I may or may not use the cat5 wire in the final, but I do like the twist. I am looking for a wire which contains more internal - the DB9 solution may actually work well but I don't know how many I have laying around - I may have a null modem cable or two but I'd need to double-check the pin-outs... Some DB9 wires have crossed pins from one side to the next...

I will test the GX16-N connectors to see if they're viable for lower signals... I'll make sure I test resistor values, etc.. using the default tweezers, and the default alligator clips in addition to these new clips to see if the value changes. I don't have any other meters to compare with so I'll do either the full 30 values with 3 each, or whatever, write down the results from each, and then average to see.... with the final clip setup whether I use the DB9, GX16-N, or other method... I'll also test the same settings with the setup I just made...


The bad thing about using 2 Cat5 sheathes is they're incredibly stiff ( I am also looking at buying some cable weave to use around the wire sheathes I choose - hopefully I can find colored sheathes as that'd look cleaner, in my opinion, than using colored heat-shrink although I plan on using colored heat-shrink underneath.

The reason there is hotglue on the Cat5 wires is because of the heat, some of the wires split in a few places ( I did check to see if happened inside the sheathe but it looks ok ) there were just a few areas so I added it as insulation - and... remember, this is temporary as a test to see if it'd work like this....

Also note: I didn't clean off manufacturing process gunk - the new one I received in the mail today had a lot of flux, etc.. on it so I'll be cleaning that one too..

Photos ( The photos here have been added to the main archive so you can download from there or just add these photos to it ): https://www.dropbox.com/s/leafmcx9l318vyw/DER_DE-5000_Future_Proof_Connector_Mod_test.zip?dl=0

Individual Photos:

Shows the clips attached to the 2 screw-post BNC Female connectors connected to the Cat5 wire - the colors showing out the end are so I know which is which... Orange / Brown is -1 / -2, and Blue / Green is +1 / +2
https://www.dropbox.com/s/72gp2cjeg96qhol/20180612_071758.jpg?dl=0

Same except you see the closed top TL-22
https://www.dropbox.com/s/bmnnksrq3byphhj/20180612_071810.jpg?dl=0

TL-22 Open so you can see the zip-tie, and soldering job along with hot glue... Note: I did clean off the original solder before doing this. I prefer Lead-Free... 2 photos of the same..
https://www.dropbox.com/s/tfhkxm2f6o3s3eu/20180612_071850.jpg?dl=0

And TL-22 open with a shot of the wires...
https://www.dropbox.com/s/2ahscyqocynsgmd/20180612_071901.jpg?dl=0
https://www.dropbox.com/s/72gp2cjeg96qhol/20180612_071758.jpg?dl=0



Edit:

So it is clear - I am definitely looking into using DB9 :-) - A lot of them, however, do not have 9 wires... I think the standard is 6 or 7 - but there are some with 8 or 9 so I'd prefer to have 8 minimum so the shield wires can be on their own instead of combined as the wires in a DB9 wire are very thin, and the trace on the pcb for the TL-2X series is about the same as 4 or more of those wires...

I am going to tally up the resistance and impedance of every single thing I put in line... So I'll show values for the GX16-8 and 4 connector for each pin ( averaged out of the 5 I have ), the current connector I have, the values for the kelvin clip wires I have, the clips themselves or the entire wire from tip to the end of the BNC connector although I am going to see about getting the connector by itself ( I did buy some which look identical so I can compare the values to see if they are the same or not..

I also ordered gold connectors so I cna show the difference in those vs tin or nickel or whatever it is these others are made of... I'll also add in the values for the BNC to RCA I have ( male and female on the RCA side, male only on BNC I believe )... Also, whichever wire I decide to use I'll add that too along with the length...

I want this project to contribute to the community so with the values and listings where I purchased the items listed, you can expect similar values and you can also choose how to build it if you decide to build it...

And the tweezers I liberated - for now I'll add BNC connectors to it...

[jrd]

Hmm.  I think you want to the drive and sample lines together under covered conductive shield tied to the guard voltage.  Whatever magnetic noise is induced on the cable should get cancelled out by the pair, and the electrostatic shield at guard voltage kills the electric field noise.  Looks alot like a balanced microphono or phono system doesn't it ?

* I'd be tempted to go for Mini XLR connectors mounted on the TL-21:
http://www.switchcraft.com/Category.aspx?Parent=806

* Then I'd get a small Bud box and drill for 4 x BNC  and 2 x mini-XLR (TB series males)
* I'd get an extra TL-21 and drill and add 2 x miniXLR (TB series males), Guard to Pin 1,  Drive to Pin 2 and Sample to Pin 3
* I'd wire it up so that even box is held at Guard potential.  Inside the box, I'd run short, maybe silver wire for kicks, from miniXLRs to BNCs.
* I'd then build a very short interconnect, maybe only 6 inches, to link the Modified TL-21 and the bud box.
   Perhaps the Right Angle mini XLR female to plug into the meter so it looks cool, and the shielded mini XLR female (silver to the box)
   For interconnect wire, I'd have to shop around for thin two-conducted shielded (Belden, Canare, etc)
* Not cheap project, but clean!  The XLR connectors are $10 a pop.  You're talking $80 just for the interconnect system mechanical parts....
It requires faith in balanced interconnects. The upside is the connectors are always useful to many other projects that need the connectors (mainly studio audio).
Overall I'd estimate the connection project to use the clips to be about $130.... This is why people cut off the BNC connectors and hack the TL-21.....

There's a reason the interconnects have to be kept short.  That DE-5000 is able to run at 100 kHz.  Please not the frequency attenuation that occurs
in the otherwise heralded, godly Canare Quad Star balanced cable (!)
http://www.canare.com/ProductItemDisplay.aspx?productItemID=53

That response graph begs one to ask how those cheap Kelvin clips' cables respond at 100 kHz measurement regime.

-- Jim

[jrd]

Let's take my last proposal, using mini XLR's - and Iterate on it for cost reduction!

* Use ordinary XLR connectors, which are much cheaper and have many available sources.
* Eliminate a pair of connections, reducing the cost by 4 connectors.

1. Modify the TL-21 by directly soldering in, and fixing by strain relief, two 1 foot sections of Balanced XLR cable.
2. Terminate XLR cable ends with 2 x Male XLR connectors.  Same scenario, Pin 1 to guard voltage, Pin 2 to Drive, Pin 3 to Sample.
3. Drill out a Bud Box for 4 x BNC and 2 x Female Panel Mount XLRs (i.e. Neutrik NC3FD)

There!  That's MUCH better costwise!  And it retains the original objective (Pairs transports under guard voltage shield end to to end! Possibly pretty looking.)