DE-5000  LCR TL-21 mod. - Page 1
Forum section: electronics / testgear

author: McBryce
author_rank: Super Contributor
timestamp: February 10, 2016, 04:20:23 am
content: Hi all,I got a DER EE DE-5000 (also sold as IET) LCR meter a while back. It came with a TL-21 connector that looks like this:http://www.japaninabox.jp/wp/wp-content/uploads/2013/08/der-ee-de-5000-high-accuracy-andheld-lcr-meter-with-tl21-tl22-tl23-iet-06.jpgThe problem is, the crocodile clips are crap. They're pretty cheap, don't grip the components pins particularly good and the wires are so short that they can be difficult to connect at all to some parts. My plan is to remove them and install 4 banana sockets so that I can use my standard Kelvin clips with it. Has anyone tried this yet? Is there enough space in the case for sockets? And is there any disadvantages to doing this? The meter is taking a 4-wire measurement, but the 4 wires actually connect at the base of the crocodile clip at the moment, so using proper Kelvin clips should actually give a more accurate reading.McBryce.

author: Lightages
author_rank: Unknown
timestamp: February 10, 2016, 04:56:02 am
content: I modified mine. I purchased some cheap Kelvin clips on ebay, cut off the ends,and soldered the cables directly to the board in place of the cheap aligator clips.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: February 10, 2016, 04:58:59 am
content: I was going to do the same thing with mine. I bought a spare tweezer set so that I could replace it if it breaks (again). I think the price was about the same.I was planning on using Mueller kelvin clips that I had as spares. I already bought the Extech LCR205 smt adapter for it too, but the blades of the adapter aren't quite long enough for a secure fit.

author: McBryce
author_rank: Super Contributor
timestamp: February 10, 2016, 05:09:55 am
content: I'd prefer not to solder the Kelvin clips onto the TL-21 as I use them on other meters too. I'll have to investigate the smallest 4mm sockets I can get and see if I can fit four of them into the case.McBryce.

author: Lightages
author_rank: Unknown
timestamp: February 10, 2016, 05:11:56 am
content: It is cheaper, easier, and better IMHO to just buy these and solder them in:http://www.ebay.com/itm/LCR-Meter-Test-Leads-Clip-Kelvin-Wires-With-2-BNC-per-Channel-Red-Black-/171907327574?hash=item280679a656:g:eLIAAOxyhXRTO-7i

author: McBryce
author_rank: Super Contributor
timestamp: February 10, 2016, 05:48:33 am
content: Yes, it's probably easier, but I doubt it's cheaper. It also means that the TL-21 then becomes a case with bulky leads (and I already have way too many leads around the room). With sockets it becomes a tidy little box and I just use the leads I already have. I've just ordered the smallest sockets I could find (for €5). I'll see if they fit when they get here.McBryce.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: February 10, 2016, 02:22:27 pm
content: Quote from: McBryce on February 10, 2016, 05:48:33 amDon't forget this is a 5-wire connection, not a 4-wire connection. If you break the kelvin leads out into their individual lines you are supposed to have a guard shield around the lines too. Even the short alligator leads use shielded cable (with all of the shields connected together to the guard pin). This supposedly becomes even more important at longer lengths.You can see the shielding here (the braided copper) soldered to the guard-line:

author: Fat
author_rank: Regular Contributor
timestamp: February 10, 2016, 10:18:22 pm
content: Here are mine made from an Ebay kelvin set with a BNC end.

author: TimFox
author_rank: Super Contributor
timestamp: February 10, 2016, 10:27:01 pm
content: I bought two extra TL-21's to make fixtures.On one, I replaced the two black cables with two teflon shielded twisted pair cables to Kelvin clips, roughly 60 cm long.On the other, I replaced the black cables with four RG-174 coax cables to BNC plugs, to allow making "black box" fixtures with binding posts at different spacings.In the black-box fixtures, I included a small switch to short the binding posts together for short-circuit calibration, using multiple-pole miniature toggles to reduce the contact resistance.I kept the original TL-21: I haven't had any problems with the alligators except that the plastic covers make them stiff.I'm looking for a good way to keep the alligators the correct distance apart (corresponding to the final spacing on the component) when doing the open-circuit calibration.

author: circuitravi
author_rank: Contributor
timestamp: February 11, 2016, 01:21:05 am
content: what is the good kelvin clip?ORone type has 2 wire connect to both kelvin clip end and other type 2 wire connect to one end.

author: TheSteve
author_rank: Unknown
timestamp: February 11, 2016, 01:26:56 am
content: They are both connected the same. The cables in the second picture loop around to the other side of the clip near the hinge.

author: McBryce
author_rank: Super Contributor
timestamp: February 11, 2016, 09:37:47 am
content: Quote from: PedroDaGr8 on February 10, 2016, 02:22:27 pmYes, I was aware of the guard connection, but I intended leaving that unconnected as my Kelvin clips (like the mods shown above) don't contain an additional shield anyway. Lots of ideas to go on though now, thanks for all the ideas and pics. I'll post a picture of what I've done when it's finished.McBryce.

author: Carrington
author_rank: Super Contributor
timestamp: February 18, 2016, 05:12:53 pm
content: Another DE-5000 LCR mod.http://designideas.cocolog-nifty.com/blog/2014/09/de-5000-test-fi.html

author: McBryce
author_rank: Super Contributor
timestamp: February 18, 2016, 08:24:34 pm
content: A bit more than I actually need, but thanks for the link. Still waiting for the 4mm sockets to arrive before I start my mod.McBryce.

author: mos6502
author_rank: Frequent Contributor
timestamp: February 18, 2016, 10:14:19 pm
content: Waitaminute ... so there's a PCB with SMD pads in the TL21 that's covered with this sticker? Why didn't they leave it exposed?I think I'll have to take a knife to mine ...

author: Lightages
author_rank: Unknown
timestamp: February 19, 2016, 01:00:32 am
content: So that it is what the circuit board is for! The problem is, as built, it stil can't do anything without soldering some wires to it. his would also render the external test connections less accurate as the circuit board would be adding its capacitance and inductance to the reading.

author: mos6502
author_rank: Frequent Contributor
timestamp: February 19, 2016, 03:29:20 am
content: You're right, one would probably want to remove the PCB to which the wires are attached, hook up the SMD PCB to the blade contacts and make a dedicated TL-21 for SMD devices.On closer inspection, the SMD pads don't have a Kelvin connection either ...

author: McBryce
author_rank: Super Contributor
timestamp: February 19, 2016, 09:23:54 am
content: Quote from: mos6502 on February 19, 2016, 03:29:20 amYou mean like the TL-22 ?McBryce.

author: mos6502
author_rank: Frequent Contributor
timestamp: February 19, 2016, 03:09:48 pm
content: Quote from: McBryce on February 19, 2016, 09:23:54 amThe tweezers aren't that great. I have them. The tips are not very precise (cheap stamped metal) and the thick cable is clumsy. Putting SMD components directly on a PCB would work better, IMHO. It's really odd that they would go to the lengths to manufacture those PCBs but then not hook them up and hide them under a sticker.

author: McBryce
author_rank: Super Contributor
timestamp: February 19, 2016, 09:56:03 pm
content: Yes, I have a TL-22 myself. It does the job more or less, but it's galaxies away from winning any prizes for design or usability. The manufacturing quality is relatively good, it's just a bad design.But back to the TL-21. I've opened mine and the PCB under the lid on mine is a non-etched PCB. So there seems to be different versions. See below.The sockets arrived. They were the smallest 4mm shrouded sockets I could find, but there's not a chance I can get 4 of them on the case, so I'll have to come up with some other solutionMcBryce.

author: Lightages
author_rank: Unknown
timestamp: February 20, 2016, 02:55:40 am
content: Quote from: McBryce on February 19, 2016, 09:56:03 pmThis is why I suggested buying another set of Kelvin leads and just soldering them directly. It is the surest and cheapest solution.

author: electr_peter
author_rank: Unknown
timestamp: August 27, 2016, 06:30:47 pm
content: I modified TL-21 adapter as well, see my postbroken-der-de-5000-tl-21-crocodile-clip-adapterTL-21 has tendency to break internal solder joints - I had to repair it.

author: markce
author_rank: Regular Contributor
timestamp: August 27, 2016, 09:41:58 pm
content: Also please have a look here:https://www.eevblog.com/forum/testgear/der-ee-de-5000-lcr-meter-with-changeable-cables/

author: Corner
author_rank: Regular Contributor
timestamp: August 15, 2020, 10:03:11 am
content: Quote from: McBryce on February 11, 2016, 09:37:47 amHi McBryce, did you manage to get yours to work perfectly? I have these leads I hand made a while ago. Each wire is just 14AWG stranded wire. I cut the plug ends off only to realise I also need a guard wire to connect onto the TL21... I should have checked these threads first before I sacrificed a pair of leads.I assume that I can't easily mod my existing leads to have a guard wire. Can I safely leave the guard wire out and only connect 4 wires to TL21? Would this affect measurements, say for small resistors and capacitors?Edit: Attach photo

author: McBryce
author_rank: Super Contributor
timestamp: August 15, 2020, 10:11:02 am
content: Hi Corner,in the end I used shielded Kelvin clips with 4x BNC connectors. I 3D printed a new housing to put it all into. This is what it looks like. The measurements with this are identical to the values I get with the original short clips.McBryce.

author: Corner
author_rank: Regular Contributor
timestamp: August 15, 2020, 12:01:36 pm
content: That looks amazing

author: jerolee
author_rank: Contributor
timestamp: August 15, 2020, 12:13:37 pm
content: Awesome piece of work, i like it.I would be interested in such a box. im struggeling with the same issue. My readings are not stable, i gues its the cheap pcb connector strips plugged into the device. Component legs straight into the clips give me better readings.Im in to get a more decent bench LCR meter anyway but $$$$$$!

author: McBryce
author_rank: Super Contributor
timestamp: August 15, 2020, 12:58:41 pm
content: The PCB I used was a blank two sided PCB. It needs to be the thinner 1mm stuff, the standard 1.5mm PCB won't fit between the blades. I didn't bother etching it, I just used a hacksaw to seperate the three/six contacts.As for the meter, I'm pretty happy with it, not looking to upgrade any time soon.McBryce.

author: Fraser
author_rank: Super Contributor
timestamp: August 15, 2020, 01:20:32 pm
content: McBryce,Would you consider sharing your 3D print files for the box please ?Best WishesFraser

author: precaud
author_rank: Frequent Contributor
timestamp: August 15, 2020, 01:30:24 pm
content: Quote from: circuitravi on February 11, 2016, 01:21:05 amWhichever one you get, check the connections to the BNC adapters and make sure they are soldered properly. Makes a big difference when measuring low-impedance parts.

author: McBryce
author_rank: Super Contributor
timestamp: August 15, 2020, 01:44:53 pm
content: Quote from: Fraser on August 15, 2020, 01:20:32 pmI think the lid file may be upside down (needs to be flipped 180 before printing). There are two versions here, one with the BNC holes and the other is blank for designing your own variation.McBryce.EDIT: I just discovered that mistakes crept into this version when I made minor tweaks. I will upload a new version later in this thread.

author: Fraser
author_rank: Super Contributor
timestamp: August 15, 2020, 03:43:37 pm
content: BrilliantThank youFraser

author: cdev
author_rank: Super Contributor
timestamp: August 16, 2020, 12:29:56 pm
content: As far as grip, they grip very strongly, and after having tried to find smaller, stronger clips for a very similar purpose, and also recently having gotten a TINY network analyzer, and given that the issue, though important to me doesn't start to get critical except at much higher frequencies, I decided to devote that same energy to developing better text fixtures to use on my nanovna. You'll be able to get the same data, but better and going much higher.People who have done the conversion, how different are your readings?Quote from: McBryce on February 10, 2016, 04:20:23 am

author: Acecool
author_rank: Regular Contributor
timestamp: August 16, 2020, 07:52:39 pm
content: I modified a box of mine.. I was thinking of using BNC connectors in the actual unit but I didn't like having to plug 4 things in.. additionally, because of the box it wouldn't fit into the slot. So I originally had 2 shielded BNC 6" leads, 4 of them... I had red and black heat shrink tubing to denote ground or one section and the other section...This worked well, but I hated the 4 connections and I didn't like the leads hanging out. It made it difficult with how much stuff was in the box. So I used GX16 connector, the Chinese airplane connector with screw cap... Ground is soldered directly to the threads to ensure ground goes through and to the shielding... It passes the calibration and works. I have 2 of the ebay alligator BNC wires ( $20 USD each or so ).. One I left with BNC, one has the GX16 connector on it.It works, and I can keep the connection permanent but typically I have to remove it to put it in the box. There is less stuff to worry about int he box now that I have a single box - the tweezers were also modified to the GX16 connector and I have yet to do the small alligators as I'll probably keep that as a control module. I do have a spare set of tweezers too and another box I have disasembled.Someone suggested I use audio XLR connectors - mini or normal. They are much higher quality, gold plated in some cases. I priced out the connectors as they are pricey but they don't screw on and have a designated ground pin. I would probably have a 1 inch lead coming out of the box too so it'll fit in the stock storage box as one issue I do have with the GX connector is that if I put the box in the unit first, then plug tweezers or the alligator clips in... I can't screw it in. I have to unplug it just a bit then I can push it in but it puts it at a slight slant. I don't want to modify the unit to let that fit as I'll probably screw it up and make it look bad, like I did with the box which I'll probably fix using spin welding.Look for my posts, I have some photos, etc.. I think.The GX16-4 connector ( the 4 pins are for each normal pin, and ground goes through the threads, then the shielding of the cable ) is the one I'm using.. I will probably switch to the higher quality XLR connectors because there is a built in ground tab to solder to, and the connectors come apart and go together much better. Plus the gold plating, etc... It'll cost quite a bit, but it will also make it much easier to just plug something in and use it, then I can plug something else in and go with it too.Right now being able to plug in a single plug and have access to alligator clips on decently long leads is nice, plus the tweezers, etc... I can just plug in and use - no need to screw it in unless I want the ground but most don't use it... although it is probably a good thing to have the ground running through the shielding. Or, maybe it'll create a capacitor effect as power does run through the + wires.Edit:Also, when I go for the XLR connectors - instead of just having the ground running through the shield... I'm thinking of having the ground run through the shield, in addition having 1 pin as a ground too. so the 5 pin connector. Still debating on this. The point of this would be so if the ground tab has an issue, with the ground going straight to another pin, on each connector I can create a jumper to go from the pin I choose for ground, and the ground tab and the shielding. This way if there is ever an issue, or it ends up fitting loosely at some point in the future... the ground will be a solid connection regardless. This is probably overkill, and I won't be using 5 core wire... it will still be ground through the shielding, but to have the ground go through a pin as well as the connector would just ensure that connection.What do you all think of that idea? Should I just go with the 4 pin with ground through the outside, or go with the 5 pin and the jumper? I'm leaning towards 5 pin just because it wouldn't be difficult to do and would make sure the ground is never in question. I've never worked with the XLR connectors so I'm not sure how well the outside connection fits - I'm assuming it is decent enough but while it can clip together, the connections have some black layer on the outside so I don't know if it is conductive or not. It could be, but it could also be a protective coating. The inside should be fine if the outside has a protective coating. But I'd rather be 100% especially as I haven't worked with them before - another reason for the 5 pin.I am also planning on getting 1 or 2 main female connectors, and the rest male - 5 or so so I can create up to 5 connections. 2 are spoken for, and I may make a small alligator clip set too just to have it in the box especially as with needing only 1 box it would mean a lot more room in the carry box. I may make a second one just so I could swap between them - but I highly doubt the machine has any way to tell, unless in software, what is connected and how it was calibrated. If it can, then 2 boxes wouldn't be a bad idea to quickly switch from one thing to another... but unplugging something and plugging the other in could be just as effective if I don't need to calibrate... but I probably do.

author: TimFox
author_rank: Super Contributor
timestamp: August 16, 2020, 07:55:15 pm
content: What gauge wire are those GX-series connectors designed for? I had trouble with them on another project.

author: Acecool
author_rank: Regular Contributor
timestamp: August 16, 2020, 08:12:27 pm
content: The tabs are pretty large on the inside but I typically heat shrink them just so they don't hit the outer shell. You could probably get a solid coax wire on them....They are used in soldering stations, heat gun / rework stations, and more... so they can handle a lot of current and they've never gotten hot on me despite pushing an iron and heat gun to its absolute highest temps and highest fan speed setting. So very little resistance - but then again it is a bigger piece of metal and the metal box of the station acts as a heatsink which could be why the wire may be warmer...You can get smaller GX connectors. GX16 is 16mm, GX12 is 12mm, which is the mini ones ( these screw in - the 16mm pushes in, then has a small turn, then a locking / set screw is used to stop it from coming undone. The 12mm - typically photos online show the GX16 instead of the 12... it has no set screw and just screws in - this does work well... )My T12 station uses the GX12 connector. It is tighter in there but it could probably fit close to the same wire inside, especially with heat wrap as the divider may be smaller... I'll take it apart to verify this - but as for the exact spec of what you can use - not sure. I wouldn't go larger than the actual pins inside the connector and those measurements are...GX16 5 pin: 1.9mm - These typically have 12 to 24v going through at or around 4 to 5 amps at 100% power to the T12 soldering station - or this is what the station itself is drawing from the wall - I'd have to double check... I saw these numbers from a video review of the KSGER T12 station... it should be 24V 4 + amps. not sure how much is making it to the tip. but that is typically in short bursts.GX16 8 pin: 1.25mm - This is used for the heat-gun and these typically have 110v going to the heating element - unsure on ampsGX12: 1.2mmThat being said, a lot of Chinese manufacturers typically under-engineer the design so these may be absolute highs for these connectors... however I've never noticed any melting, arcing, etc.. but I go through and do some extra work on them to be absolutely sure there won't be an issue by adding heat shrink, redoing the joints, etc...Also, the connectors likely have a lot of flaws in them so it is quite possible that there is a lot of resistance within them... they are inexpensive and not always the best quality - hence one reason I want to switch to something better made.I'd be spending around $30 in connectors for the XLR-5 connectors... normal or mini.

author: TimFox
author_rank: Super Contributor
timestamp: August 16, 2020, 09:14:17 pm
content: My problem was with the internal dimension of the solder cups--extremely small internal diameter. I don't remember which suffix on the GX.

author: sequoia
author_rank: Unknown
timestamp: August 17, 2020, 01:40:02 am
content: I wanted to use Kelvin clips that I use with bench multimeters. So, I ended up adding banana jacks:

author: Acecool
author_rank: Regular Contributor
timestamp: August 17, 2020, 02:07:56 am
content: They can be quite tricky to solder and get to.. it is best to pre-tin everything and blob up the connectors. There is a cradle and there is a hole. Don't use the hole - just cradle the wire and that's it.I had an issue with mine too once where it felt almost like it was difficult to solder to the pieces and get everything squeezed into the connector. I don't recall why this was the case. I know it can sometimes be odd to get it packed in, and make the slight turn required on the GX16 ( if you measure the connector around the female plug at the widest point - the rim which is held on by the retained nut, without measuring the nut - that should give that value clamped to the nearest mm... )I have to redo my hot air gun so I'll put it on video.'@sequoiaThe banana jacks actually look decent. I had around the same length of 4x BNC connectors and I didn't like all the mass... the banana jacks are nice but it doesn't give the option to pass on any shielding to the tool if it has that option, or pass it on to an extension is the only downside I see to it.

author: mansaxel
author_rank: Super Contributor
timestamp: August 17, 2020, 07:02:48 am
content: Quote from: Acecool on August 16, 2020, 08:12:27 pmMy 5€-Cents:A Neutrik XLR is probably not going to wear out on you. I'd get the silver plated ones if I did it, because they hold up better to mating cycles than the gold ones. Mouser has NC5FXX (female cable) for ~ €6, and mating male chassis connector NC5MP for around €7. I chose this combination of male / female because the male chassis is narrower (it's the old Cannon / Switchcraft standard for a 19mm hole with two 3mm holes top and bottom for screws) and should fit better on the TL style box. The Guard connection IMNSHO should get a separate pin, and also be connected to the shell via the dedicated tab. From pure habit, I'd do the following pin-out:GuardPositive clamp drivePositive clamp senseNegative clamp driveNegative clamp sense(Does the terminology make sense?)This way you can extend with COTS DMX512 cable if you wish.If you want something smaller, I'd research two things;Screw-lock DIN connectors as made by Binder. They've been used for microphone connection when the RFI qualities of XLR aren't up to spec.Automation machinery M series connectors. Smaller than the Binder. TE makes an extensive range. I think you'd be best off with a M12 style housing.

author: Corner
author_rank: Regular Contributor
timestamp: August 17, 2020, 07:10:44 am
content: Quote from: sequoia on August 17, 2020, 01:40:02 amIt's hard to see but I assume those are 14 AWG wires from the looks. How did you manage to cram them all in that little hole? Did you make the hole bigger?

author: sequoia
author_rank: Unknown
timestamp: August 17, 2020, 09:13:03 am
content: Quote from: Acecool on August 17, 2020, 02:07:56 amMy Kelvin clips set doesn't have a guard/shielding connection. But presumably if one has Kelvin clip set with banana plugs, it would also have banana plug for the guard/shield (?). Then should be able to plug in directly to TL-21 guard socket? (or may need to make banana plug to banana jack adapter cable if have safety banana plug...).Btw, is there any bench multimeters (with 4-Wire measurement terminals) that also have connection for guard/shielding?

author: sequoia
author_rank: Unknown
timestamp: August 17, 2020, 09:23:54 am
content: Quote from: Corner on August 17, 2020, 07:10:44 amYes, I had to modify the plastic case little bit, to enlarge the opening enough to fit through 4 of those 14 AWG silicone cables. Could have used thinner cable, but then it would not have fit nicely to those "safety" banana jacks....

author: Acecool
author_rank: Regular Contributor
timestamp: August 17, 2020, 12:01:33 pm
content: Yeah, I'm leaning towards 5 pin - basically if the end tool being plugged in has a ground then it can be used from the pin instead of the ground tab with xlr... and if an extension is used then it can go through shielding, ground pin and also the pin itself.I'll see where I posted my images in a bit to show mine - I did make the hole bigger when it was the 4 shielded BNC cables... with the GX connector, I had to make it much bigger and I cut the PCB just so the threads don't cut into it. I also soldered the ground wire directly to the threads - required lots of heat and time with my old iron..The XLR plugs just seem much higher quality...And I am leaning towards the gold, but it should be nickel underneath but I'll double check. I was setting up 2 orders - one mini, one large. One of the component sites had them for less money than on eBay too.. Still expensive... I will double check regarding the nickel only. Although, if I do use the hold plated - gold on gold should last a very long time since I'll be modifying the tools / attachments to use the new connectors. Right now using GX16... - also I got the measurement section wrong... it is 16mm but I can't recall where you measure.Also, I was going to do this for the GX connector, but I've decided to wait until I get the XLR plugs - make more attachments... ie: GX to BNC breakout... GX to Banana, and so on... Now XLR to XXX --- the good thing about going to Banana or BNC, or whatever... I could always have the ground Banana come with... ie: the guard plug. So if you use an adapter to go from XLR to Banana, then you end up with 5 plugs. To BNC you end up with 2 BNC plus one banana... And all of these will be small so they'll all fit in the carry box.As far as soldering the GX connectors - not a fan. I just redid my heat gun because I wasn't happy. Added a heat-shrink tube with glue as strain relief - and it is super stiff now right there, aand works as intended... but the wires were super short... it had to be because there is no space to put it in.. .this is what I don't like about the GX connectors... the mini GX are better than the large, but still annoying. The XLR connectors seem a lot better as they are longer. I also did redid the pin-out for the heatgun so the white wire for the heat gun ( because the thick white wire is in the center, and I used the wire default wire positions as the new pin out )... so no need to cross wires. I also alternated heat shrink - so the center pin has heat shrink ( ie pin 8, 1 / 7, and 3 / 5 all have heat shrink with 2, 4 and 6 without )... then a large heat shrink to add a barrier between the pins and the wall of the connector.It looks so good right now... I wouldn't want to do it again though... not a fan of the GX normal size connectors.... I'll be placing the order for the XLR soon.

author: mansaxel
author_rank: Super Contributor
timestamp: August 17, 2020, 01:18:38 pm
content: Quote from: Acecool on August 17, 2020, 12:01:33 pmHmm, shouldn't that be "To BNC you end up with 4 BNC"? I'm thinking the Guard connection should be shield on all connectors, whether driver or sense. They're all sensitive, and borderline RF if measuring @ 100KHz. There are no problems doing another Guard banana in parallel, of course. But its efficiency as a RF shunt goes down with length.

author: McBryce
author_rank: Super Contributor
timestamp: August 18, 2020, 08:09:16 am
content: Quote from: cdev on August 16, 2020, 12:29:56 pmI did a few quick comparisons last night:Sample Capacitors: 33pf Ceramic, 47nf Multilayer Ceramic, 470µf (cheap crap) ElectrolyticResults:Plugged directly into slots on meter = 33.3pf - 48.50nf - 394µfOriginal unmodded TL-21 = 33.7pf - 47.75nf - 394µfMy mod - 4x BNC / shielded Kelvin clips = 33.4pf - 48.38nf - 394µfSo all results are very similar, just with my BNC solution, I can leave the LCR meter on the shelf and have half a metre of cable to the component.The meter was of course recalibrated each time I swapped the leads.McBryce.

author: donlisms
author_rank: Frequent Contributor
timestamp: September 15, 2020, 01:48:54 pm
content: I would have been interested in ESR and low resistance readings, where Kelvin connections can really do their thing... Could you, would you?

author: Electro Fan
author_rank: Super Contributor
timestamp: September 15, 2020, 05:46:09 pm
content: - makes a pretty good case for the benefit of the guard connectionhttps://youtu.be/UTCKNm-PYWs

author: jerolee
author_rank: Contributor
timestamp: October 03, 2020, 10:49:56 am
content: McBryce was so friendly to print a box for my meter. It works a treat! The small alligator clips didnt pass the Cal half the time and readings were odd the least to say.Now with the 4 lead extensions, the readings are fine. awesome mod.Thanks McBryce!.

author: beowulfenator
author_rank: Contributor
timestamp: October 17, 2020, 10:25:28 pm
content: Hi! I am modding my TL-21, and ran into some issues. I've tried attaching kelvin clips with short (15cm) and thick (16AWG) wires directly to the little PCB inside the TL-21.Nothing is shielded. The system calibrates OK, but touching the wires or clips while measuring adds from 5 to 10 pF to the measurement.Does shielding solve this problem? Also, does the shield need to be grounded to work, or does it provide a benefit even without grounding?In other words, should I replace the thick unshielded wires with thinner, but shielded wires?Thank you!

author: beowulfenator
author_rank: Contributor
timestamp: October 19, 2020, 07:28:02 pm
content: In case anybody reads this seemingly dead thread, here are a few of my notes on the project.1. Unshielded cables are not an option. Touching the insulated cable with a hand is enough to throw off the measurement.2. Shielding works well enough even without grounding.3. Clean your flux after soldering! The device is sensitive enough to pick up the 20 MOhm path between terminals across the flux residue on the board.

author: uski
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:40:49 am
content: Hey, does the DE 5000 comes with a backlight ? I don't remember the one I used to have one !

author: McBryce
author_rank: Super Contributor
timestamp: October 20, 2020, 07:51:42 am
content: Yes, it has a weak blue backlight.For those wanting to print the case seen above, here's the final model files.McBryce.

author: pdewestvries
author_rank: Newbie
timestamp: January 14, 2021, 02:45:00 pm
content: This my solution.For about 3€ I orderded an assembly with 4 BNC connectorshttps://nl.aliexpress.com/item/32821941000.html?spm=a2g0s.9042311.0.0.27424c4dOL721xto connect the 7€ Kelvin leadhttps://nl.aliexpress.com/item/32505106470.html?spm=a2g0s.9042311.0.0.27424c4dtt72tJUsed a piece two layer pcb board for the fingers. With a small drill I made the correct layout for the connections and attached the BNC connectors to the pcb board.The pictures show the result

author: BroMarduk
author_rank: Unknown
timestamp: January 26, 2021, 06:22:34 pm
content: The Voltlog guy has a board available on Tindie that MAY work in the DE-5000 and has some big pads to attach the wires. I have a couple on the way to try out.https://www.tindie.com/products/voltlog/lcr-meter-kelvin-test-lead-adapter-pcb/

author: McBryce
author_rank: Super Contributor
timestamp: January 27, 2021, 08:04:27 am
content: Quote from: BroMarduk on January 26, 2021, 06:22:34 pmThey look like 1.6mm boards. They'll be extremely difficult to insert, the original boards are 0.5mm.McBryce.

author: Hydron
author_rank: Super Contributor
timestamp: January 27, 2021, 09:55:48 am
content: Originals are actually 1mm not 0.5, but I agree, 1.6 is gonna be tight. Best to just order your own from the usual cheapo-pcb suspects.

author: McBryce
author_rank: Super Contributor
timestamp: January 27, 2021, 10:14:10 am
content: Quote from: Hydron on January 27, 2021, 09:55:48 amDoh, yeah. Posted before my first coffee.McBryce.

author: BroMarduk
author_rank: Unknown
timestamp: January 29, 2021, 03:29:42 pm
content: Thanks for noticing that. I will not be trying to force them into the DE-5000 now, that's for sure. I was actually thinking the spacing of the tabs might be different, not the thickness.If anyone does happen to OSH out a board let us know.

author: McBryce
author_rank: Super Contributor
timestamp: January 29, 2021, 03:38:19 pm
content: The "layout" is so simple, I just "etched" the separators on a blank double-sided PCB with a hacksaw.McBryce.

author: ozkarah
author_rank: Regular Contributor
timestamp: March 13, 2023, 09:36:49 pm
content: Finally, I had time to build my modified version of the Kelvin Clip adapter for DE-5000. Thanks, McBryce for sharing his adapter from which I have been inspired very much.My primary goals for the modifications were:To be able to use the adapter both on horizontal and angled vertical positions. Because of the length of the BNC connectors of the cable I had to shift the female connectors on the adapter a little bit upper and in a slightly angled position.To use less wiring inside the adapter I designed the PCB layout compatible with the current positions of the inner pins of female BNC connectors. Soldering a small length (3-4mm) of wire between the pin and PCB was enough.Having a pair of discharging pads on the top. (through a 1K resistor)Used the following connectors and a double-sided PCB with 0.8 mm thickness.L-KLS1-BNC015https://www.aliexpress.com/item/32472482265.htmlHere are the pics:

author: McBryce
author_rank: Super Contributor
timestamp: March 14, 2023, 08:24:18 am
content: Quote from: ozkarah on March 13, 2023, 09:36:49 pmVery cool improvements!McBryce.

author: ozkarah
author_rank: Regular Contributor
timestamp: March 14, 2023, 12:07:04 pm
content: So far, I am happy with the results. As posted before, cleaning the flux residues and keeping the separating gaps as larger as possible is important.I am planning to decrease the cable length of the clips for better stability. 50 cm is more than enough for my use.STL files are uploaded to:https://www.thingiverse.com/thing:5909801

author: mawyatt
author_rank: Super Contributor
timestamp: March 14, 2023, 02:55:34 pm
content: Quote from: ozkarah on March 13, 2023, 09:36:49 pmNice work, like the 3D printed mounting fixture for the BNCsOur solution wasn't as nice but simple. Basically get another TL-21 and replace the TL-21 cables with 4 short coaxial cables with BNC connectors to mate with the various LCR fixtures we utilize.We found that with SMD fixtures the DE-5000 performs admirably as compared to our lab bench LCR meters, TH2830 and IM3536.Best

author: Electro Fan
author_rank: Super Contributor
timestamp: August 23, 2023, 02:46:10 am
content: I realize this thread has been dormant for awhile but it looked like a good place to get some guidance. ThxI'm finally getting around to adding some longer cables to the DE-5000. I bought some shielded cables with Kelvin clips and BNC connectors (that I have removed), and now I'm trying to figure out the connection points to the PCB.I saw a post from IliyaOsnovikov on Defpom's youtube channel that said "Contacts "-2" and "+2" provide test signal and the other two "-1" and "+1" are sensing voltage." My particular Kelvin clips have the cables connected through just one handle side, so presumably the wire is slightly longer to the the opposite side. The post I saw went on to say "I wanted to keep a voltage sensing wire inside a shield as far as possible, right to an alligator clip contact. But the other wire supplying test signal can be run from one side of an alligator clip to another without shielding."Maybe not a big deal either way, but thought I'd double check to confirm Iliya's wiring approach... ?Thanks

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2023, 08:22:01 am
content: I am planning on shielding both sides, but shielding the driven signal might not matter. That project is sitting on my workbench again.

author: audiotubes
author_rank: Regular Contributor
timestamp: December 28, 2023, 09:26:07 pm
content: What about just splicing kelvin clips to the existing wires rather than soldering them to the board? Is that less than optimal?With no post office here since last January and 40 bucks a pop for the DER box, I'm reluctant to take the chance to screw something up.

author: korlatos
author_rank: Regular Contributor
timestamp: December 29, 2023, 05:48:50 pm
content: Here is a very simple and effective mod using an off-the-shelf product. You can buy ZB-L100K on several well-known sites both in the USA and in China. The price is low ($20-27) and the quality is quite decent. All four Kelvin clip wires are separately shielded. You may need to file the TL-21 cable entry point, as the ZB cable diameter is a bit too large.

author: ufocia
author_rank: Newbie
timestamp: February 20, 2024, 05:13:01 am
content: No need to modify the meter. Just bevel the ends of the blades on the adapter so they can open up the contacts in the meter. Also, the adapter installs upside down, i.e. cable on the left, to match the guard, hi, lo.

author: igor78
author_rank: Contributor
timestamp: July 08, 2024, 12:18:17 am
content: I modified the original PCB herehttps://www.tindie.com/products/voltlog/lcr-meter-kelvin-test-lead-adapter-pcb-set-of-2/to fit DER DE-5000See attached gerbers.gerbers.zip(19.5 kB - downloaded 127 times.)

author: audiotubes
author_rank: Regular Contributor
timestamp: January 05, 2025, 06:17:20 pm
content: Hi Guys,I bought a few extra TL-21 boxes but when I looked for them during my vacation (which is sadly over already) I couldn't find anything.Does anybody know of a source inside the EU for these? Our Post is basically rejecting anything that comes from outside the EU for the last years, it doesn't even go to Customs and just gets sent back. We have no hope to buy anything from ebay and I don't use scamazon.Thanks.